kvm_main.c 119.2 KB
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// SPDX-License-Identifier: GPL-2.0-only
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/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * This module enables machines with Intel VT-x extensions to run virtual
 * machines without emulation or binary translation.
 *
 * Copyright (C) 2006 Qumranet, Inc.
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 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
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 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 */

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#include <kvm/iodev.h>
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#include <linux/kvm_host.h>
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#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
#include <linux/debugfs.h>
#include <linux/highmem.h>
#include <linux/file.h>
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#include <linux/syscore_ops.h>
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#include <linux/cpu.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/stat.h>
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#include <linux/cpumask.h>
#include <linux/smp.h>
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#include <linux/anon_inodes.h>
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#include <linux/profile.h>
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#include <linux/kvm_para.h>
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#include <linux/pagemap.h>
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#include <linux/mman.h>
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#include <linux/swap.h>
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#include <linux/bitops.h>
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#include <linux/spinlock.h>
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#include <linux/compat.h>
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#include <linux/srcu.h>
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#include <linux/hugetlb.h>
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#include <linux/slab.h>
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#include <linux/sort.h>
#include <linux/bsearch.h>
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#include <linux/io.h>
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#include <linux/lockdep.h>
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#include <linux/kthread.h>
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#include <asm/processor.h>
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#include <asm/ioctl.h>
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#include <linux/uaccess.h>
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#include "coalesced_mmio.h"
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#include "async_pf.h"
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#include "vfio.h"
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#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>

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/* Worst case buffer size needed for holding an integer. */
#define ITOA_MAX_LEN 12

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MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

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/* Architectures should define their poll value according to the halt latency */
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unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
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module_param(halt_poll_ns, uint, 0644);
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EXPORT_SYMBOL_GPL(halt_poll_ns);
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/* Default doubles per-vcpu halt_poll_ns. */
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unsigned int halt_poll_ns_grow = 2;
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module_param(halt_poll_ns_grow, uint, 0644);
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EXPORT_SYMBOL_GPL(halt_poll_ns_grow);
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/* The start value to grow halt_poll_ns from */
unsigned int halt_poll_ns_grow_start = 10000; /* 10us */
module_param(halt_poll_ns_grow_start, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start);

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/* Default resets per-vcpu halt_poll_ns . */
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unsigned int halt_poll_ns_shrink;
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module_param(halt_poll_ns_shrink, uint, 0644);
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EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
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/*
 * Ordering of locks:
 *
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 *	kvm->lock --> kvm->slots_lock --> kvm->irq_lock
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 */

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DEFINE_MUTEX(kvm_lock);
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static DEFINE_RAW_SPINLOCK(kvm_count_lock);
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LIST_HEAD(vm_list);
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static cpumask_var_t cpus_hardware_enabled;
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static int kvm_usage_count;
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static atomic_t hardware_enable_failed;
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static struct kmem_cache *kvm_vcpu_cache;
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static __read_mostly struct preempt_ops kvm_preempt_ops;
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static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
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struct dentry *kvm_debugfs_dir;
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EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
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static int kvm_debugfs_num_entries;
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static const struct file_operations stat_fops_per_vm;
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static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
			   unsigned long arg);
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#ifdef CONFIG_KVM_COMPAT
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static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
				  unsigned long arg);
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#define KVM_COMPAT(c)	.compat_ioctl	= (c)
#else
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/*
 * For architectures that don't implement a compat infrastructure,
 * adopt a double line of defense:
 * - Prevent a compat task from opening /dev/kvm
 * - If the open has been done by a 64bit task, and the KVM fd
 *   passed to a compat task, let the ioctls fail.
 */
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static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl,
				unsigned long arg) { return -EINVAL; }
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static int kvm_no_compat_open(struct inode *inode, struct file *file)
{
	return is_compat_task() ? -ENODEV : 0;
}
#define KVM_COMPAT(c)	.compat_ioctl	= kvm_no_compat_ioctl,	\
			.open		= kvm_no_compat_open
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#endif
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static int hardware_enable_all(void);
static void hardware_disable_all(void);
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static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
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static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn);
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__visible bool kvm_rebooting;
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EXPORT_SYMBOL_GPL(kvm_rebooting);
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#define KVM_EVENT_CREATE_VM 0
#define KVM_EVENT_DESTROY_VM 1
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
static unsigned long long kvm_createvm_count;
static unsigned long long kvm_active_vms;

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__weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
						   unsigned long start, unsigned long end)
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{
}

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bool kvm_is_zone_device_pfn(kvm_pfn_t pfn)
{
	/*
	 * The metadata used by is_zone_device_page() to determine whether or
	 * not a page is ZONE_DEVICE is guaranteed to be valid if and only if
	 * the device has been pinned, e.g. by get_user_pages().  WARN if the
	 * page_count() is zero to help detect bad usage of this helper.
	 */
	if (!pfn_valid(pfn) || WARN_ON_ONCE(!page_count(pfn_to_page(pfn))))
		return false;

	return is_zone_device_page(pfn_to_page(pfn));
}

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bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
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{
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	/*
	 * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting
	 * perspective they are "normal" pages, albeit with slightly different
	 * usage rules.
	 */
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	if (pfn_valid(pfn))
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		return PageReserved(pfn_to_page(pfn)) &&
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		       !is_zero_pfn(pfn) &&
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		       !kvm_is_zone_device_pfn(pfn);
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	return true;
}

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bool kvm_is_transparent_hugepage(kvm_pfn_t pfn)
{
	struct page *page = pfn_to_page(pfn);

	if (!PageTransCompoundMap(page))
		return false;

	return is_transparent_hugepage(compound_head(page));
}

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/*
 * Switches to specified vcpu, until a matching vcpu_put()
 */
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void vcpu_load(struct kvm_vcpu *vcpu)
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{
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	int cpu = get_cpu();
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	__this_cpu_write(kvm_running_vcpu, vcpu);
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	preempt_notifier_register(&vcpu->preempt_notifier);
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	kvm_arch_vcpu_load(vcpu, cpu);
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	put_cpu();
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}
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EXPORT_SYMBOL_GPL(vcpu_load);
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void vcpu_put(struct kvm_vcpu *vcpu)
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{
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	preempt_disable();
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	kvm_arch_vcpu_put(vcpu);
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	preempt_notifier_unregister(&vcpu->preempt_notifier);
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	__this_cpu_write(kvm_running_vcpu, NULL);
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	preempt_enable();
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}
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EXPORT_SYMBOL_GPL(vcpu_put);
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/* TODO: merge with kvm_arch_vcpu_should_kick */
static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req)
{
	int mode = kvm_vcpu_exiting_guest_mode(vcpu);

	/*
	 * We need to wait for the VCPU to reenable interrupts and get out of
	 * READING_SHADOW_PAGE_TABLES mode.
	 */
	if (req & KVM_REQUEST_WAIT)
		return mode != OUTSIDE_GUEST_MODE;

	/*
	 * Need to kick a running VCPU, but otherwise there is nothing to do.
	 */
	return mode == IN_GUEST_MODE;
}

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static void ack_flush(void *_completed)
{
}

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static inline bool kvm_kick_many_cpus(const struct cpumask *cpus, bool wait)
{
	if (unlikely(!cpus))
		cpus = cpu_online_mask;

	if (cpumask_empty(cpus))
		return false;

	smp_call_function_many(cpus, ack_flush, NULL, wait);
	return true;
}

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bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
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				 struct kvm_vcpu *except,
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				 unsigned long *vcpu_bitmap, cpumask_var_t tmp)
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{
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	int i, cpu, me;
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	struct kvm_vcpu *vcpu;
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	bool called;
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	me = get_cpu();
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	kvm_for_each_vcpu(i, vcpu, kvm) {
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		if ((vcpu_bitmap && !test_bit(i, vcpu_bitmap)) ||
		    vcpu == except)
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			continue;

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		kvm_make_request(req, vcpu);
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		cpu = vcpu->cpu;
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		if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
			continue;
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		if (tmp != NULL && cpu != -1 && cpu != me &&
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		    kvm_request_needs_ipi(vcpu, req))
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			__cpumask_set_cpu(cpu, tmp);
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	}
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	called = kvm_kick_many_cpus(tmp, !!(req & KVM_REQUEST_WAIT));
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	put_cpu();
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	return called;
}

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bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
				      struct kvm_vcpu *except)
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{
	cpumask_var_t cpus;
	bool called;

	zalloc_cpumask_var(&cpus, GFP_ATOMIC);

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	called = kvm_make_vcpus_request_mask(kvm, req, except, NULL, cpus);
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	free_cpumask_var(cpus);
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	return called;
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}

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bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
{
	return kvm_make_all_cpus_request_except(kvm, req, NULL);
}

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#ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
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void kvm_flush_remote_tlbs(struct kvm *kvm)
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{
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	/*
	 * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in
	 * kvm_make_all_cpus_request.
	 */
	long dirty_count = smp_load_acquire(&kvm->tlbs_dirty);

	/*
	 * We want to publish modifications to the page tables before reading
	 * mode. Pairs with a memory barrier in arch-specific code.
	 * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
	 * and smp_mb in walk_shadow_page_lockless_begin/end.
	 * - powerpc: smp_mb in kvmppc_prepare_to_enter.
	 *
	 * There is already an smp_mb__after_atomic() before
	 * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
	 * barrier here.
	 */
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	if (!kvm_arch_flush_remote_tlb(kvm)
	    || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
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		++kvm->stat.remote_tlb_flush;
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	cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
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}
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EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
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#endif
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void kvm_reload_remote_mmus(struct kvm *kvm)
{
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	kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
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}
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#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
					       gfp_t gfp_flags)
{
	gfp_flags |= mc->gfp_zero;

	if (mc->kmem_cache)
		return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
	else
		return (void *)__get_free_page(gfp_flags);
}

int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
{
	void *obj;

	if (mc->nobjs >= min)
		return 0;
	while (mc->nobjs < ARRAY_SIZE(mc->objects)) {
		obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT);
		if (!obj)
			return mc->nobjs >= min ? 0 : -ENOMEM;
		mc->objects[mc->nobjs++] = obj;
	}
	return 0;
}

int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
{
	return mc->nobjs;
}

void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
{
	while (mc->nobjs) {
		if (mc->kmem_cache)
			kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
		else
			free_page((unsigned long)mc->objects[--mc->nobjs]);
	}
}

void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
{
	void *p;

	if (WARN_ON(!mc->nobjs))
		p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
	else
		p = mc->objects[--mc->nobjs];
	BUG_ON(!p);
	return p;
}
#endif

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static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
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{
	mutex_init(&vcpu->mutex);
	vcpu->cpu = -1;
	vcpu->kvm = kvm;
	vcpu->vcpu_id = id;
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	vcpu->pid = NULL;
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	rcuwait_init(&vcpu->wait);
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	kvm_async_pf_vcpu_init(vcpu);
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	vcpu->pre_pcpu = -1;
	INIT_LIST_HEAD(&vcpu->blocked_vcpu_list);

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	kvm_vcpu_set_in_spin_loop(vcpu, false);
	kvm_vcpu_set_dy_eligible(vcpu, false);
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	vcpu->preempted = false;
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	vcpu->ready = false;
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	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
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}

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void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
	kvm_arch_vcpu_destroy(vcpu);
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	/*
	 * No need for rcu_read_lock as VCPU_RUN is the only place that changes
	 * the vcpu->pid pointer, and at destruction time all file descriptors
	 * are already gone.
	 */
	put_pid(rcu_dereference_protected(vcpu->pid, 1));

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	free_page((unsigned long)vcpu->run);
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	kmem_cache_free(kvm_vcpu_cache, vcpu);
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}
EXPORT_SYMBOL_GPL(kvm_vcpu_destroy);

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#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
{
	return container_of(mn, struct kvm, mmu_notifier);
}

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static void kvm_mmu_notifier_invalidate_range(struct mmu_notifier *mn,
					      struct mm_struct *mm,
					      unsigned long start, unsigned long end)
{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
	int idx;

	idx = srcu_read_lock(&kvm->srcu);
	kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
	srcu_read_unlock(&kvm->srcu, idx);
}

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static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
					struct mm_struct *mm,
					unsigned long address,
					pte_t pte)
{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
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	int idx;
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	idx = srcu_read_lock(&kvm->srcu);
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	spin_lock(&kvm->mmu_lock);
	kvm->mmu_notifier_seq++;
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	if (kvm_set_spte_hva(kvm, address, pte))
		kvm_flush_remote_tlbs(kvm);

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	spin_unlock(&kvm->mmu_lock);
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	srcu_read_unlock(&kvm->srcu, idx);
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}

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static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
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					const struct mmu_notifier_range *range)
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{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
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	int need_tlb_flush = 0, idx;
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	idx = srcu_read_lock(&kvm->srcu);
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	spin_lock(&kvm->mmu_lock);
	/*
	 * The count increase must become visible at unlock time as no
	 * spte can be established without taking the mmu_lock and
	 * count is also read inside the mmu_lock critical section.
	 */
	kvm->mmu_notifier_count++;
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	need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end);
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	need_tlb_flush |= kvm->tlbs_dirty;
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	/* we've to flush the tlb before the pages can be freed */
	if (need_tlb_flush)
		kvm_flush_remote_tlbs(kvm);
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	spin_unlock(&kvm->mmu_lock);
	srcu_read_unlock(&kvm->srcu, idx);
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	return 0;
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}

static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
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					const struct mmu_notifier_range *range)
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{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);

	spin_lock(&kvm->mmu_lock);
	/*
	 * This sequence increase will notify the kvm page fault that
	 * the page that is going to be mapped in the spte could have
	 * been freed.
	 */
	kvm->mmu_notifier_seq++;
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	smp_wmb();
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	/*
	 * The above sequence increase must be visible before the
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	 * below count decrease, which is ensured by the smp_wmb above
	 * in conjunction with the smp_rmb in mmu_notifier_retry().
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	 */
	kvm->mmu_notifier_count--;
	spin_unlock(&kvm->mmu_lock);

	BUG_ON(kvm->mmu_notifier_count < 0);
}

static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
					      struct mm_struct *mm,
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					      unsigned long start,
					      unsigned long end)
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{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
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	int young, idx;
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	idx = srcu_read_lock(&kvm->srcu);
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	spin_lock(&kvm->mmu_lock);

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	young = kvm_age_hva(kvm, start, end);
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	if (young)
		kvm_flush_remote_tlbs(kvm);

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	spin_unlock(&kvm->mmu_lock);
	srcu_read_unlock(&kvm->srcu, idx);

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	return young;
}

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static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
					struct mm_struct *mm,
					unsigned long start,
					unsigned long end)
{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
	int young, idx;

	idx = srcu_read_lock(&kvm->srcu);
	spin_lock(&kvm->mmu_lock);
	/*
	 * Even though we do not flush TLB, this will still adversely
	 * affect performance on pre-Haswell Intel EPT, where there is
	 * no EPT Access Bit to clear so that we have to tear down EPT
	 * tables instead. If we find this unacceptable, we can always
	 * add a parameter to kvm_age_hva so that it effectively doesn't
	 * do anything on clear_young.
	 *
	 * Also note that currently we never issue secondary TLB flushes
	 * from clear_young, leaving this job up to the regular system
	 * cadence. If we find this inaccurate, we might come up with a
	 * more sophisticated heuristic later.
	 */
	young = kvm_age_hva(kvm, start, end);
	spin_unlock(&kvm->mmu_lock);
	srcu_read_unlock(&kvm->srcu, idx);

	return young;
}

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static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
				       struct mm_struct *mm,
				       unsigned long address)
{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
	int young, idx;

	idx = srcu_read_lock(&kvm->srcu);
	spin_lock(&kvm->mmu_lock);
	young = kvm_test_age_hva(kvm, address);
	spin_unlock(&kvm->mmu_lock);
	srcu_read_unlock(&kvm->srcu, idx);

	return young;
}

588 589 590 591
static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
				     struct mm_struct *mm)
{
	struct kvm *kvm = mmu_notifier_to_kvm(mn);
592 593 594
	int idx;

	idx = srcu_read_lock(&kvm->srcu);
595
	kvm_arch_flush_shadow_all(kvm);
596
	srcu_read_unlock(&kvm->srcu, idx);
597 598
}

599
static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
600
	.invalidate_range	= kvm_mmu_notifier_invalidate_range,
601 602 603
	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
604
	.clear_young		= kvm_mmu_notifier_clear_young,
A
Andrea Arcangeli 已提交
605
	.test_young		= kvm_mmu_notifier_test_young,
606
	.change_pte		= kvm_mmu_notifier_change_pte,
607
	.release		= kvm_mmu_notifier_release,
608
};
609 610 611 612 613 614 615 616 617 618 619 620 621 622

static int kvm_init_mmu_notifier(struct kvm *kvm)
{
	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
}

#else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */

static int kvm_init_mmu_notifier(struct kvm *kvm)
{
	return 0;
}

623 624
#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */

625
static struct kvm_memslots *kvm_alloc_memslots(void)
626 627
{
	int i;
628
	struct kvm_memslots *slots;
629

630
	slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT);
631 632 633
	if (!slots)
		return NULL;

634
	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
635
		slots->id_to_index[i] = -1;
636 637 638 639 640 641 642 643 644 645 646 647 648

	return slots;
}

static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
{
	if (!memslot->dirty_bitmap)
		return;

	kvfree(memslot->dirty_bitmap);
	memslot->dirty_bitmap = NULL;
}

649
static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
650
{
651
	kvm_destroy_dirty_bitmap(slot);
652

653
	kvm_arch_free_memslot(kvm, slot);
654

655 656
	slot->flags = 0;
	slot->npages = 0;
657 658 659 660 661 662 663 664 665 666
}

static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
{
	struct kvm_memory_slot *memslot;

	if (!slots)
		return;

	kvm_for_each_memslot(memslot, slots)
667
		kvm_free_memslot(kvm, memslot);
668 669

	kvfree(slots);
670 671
}

672 673 674 675 676 677 678 679 680
static void kvm_destroy_vm_debugfs(struct kvm *kvm)
{
	int i;

	if (!kvm->debugfs_dentry)
		return;

	debugfs_remove_recursive(kvm->debugfs_dentry);

681 682 683 684 685
	if (kvm->debugfs_stat_data) {
		for (i = 0; i < kvm_debugfs_num_entries; i++)
			kfree(kvm->debugfs_stat_data[i]);
		kfree(kvm->debugfs_stat_data);
	}
686 687 688 689 690 691 692 693 694 695 696 697
}

static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
{
	char dir_name[ITOA_MAX_LEN * 2];
	struct kvm_stat_data *stat_data;
	struct kvm_stats_debugfs_item *p;

	if (!debugfs_initialized())
		return 0;

	snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
698
	kvm->debugfs_dentry = debugfs_create_dir(dir_name, kvm_debugfs_dir);
699 700 701

	kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
					 sizeof(*kvm->debugfs_stat_data),
702
					 GFP_KERNEL_ACCOUNT);
703 704 705 706
	if (!kvm->debugfs_stat_data)
		return -ENOMEM;

	for (p = debugfs_entries; p->name; p++) {
707
		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
708 709 710 711
		if (!stat_data)
			return -ENOMEM;

		stat_data->kvm = kvm;
712
		stat_data->dbgfs_item = p;
713
		kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
714 715 716
		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
				    kvm->debugfs_dentry, stat_data,
				    &stat_fops_per_vm);
717 718 719 720
	}
	return 0;
}

721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
/*
 * Called after the VM is otherwise initialized, but just before adding it to
 * the vm_list.
 */
int __weak kvm_arch_post_init_vm(struct kvm *kvm)
{
	return 0;
}

/*
 * Called just after removing the VM from the vm_list, but before doing any
 * other destruction.
 */
void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
{
}

738
static struct kvm *kvm_create_vm(unsigned long type)
A
Avi Kivity 已提交
739
{
740
	struct kvm *kvm = kvm_arch_alloc_vm();
741 742
	int r = -ENOMEM;
	int i;
A
Avi Kivity 已提交
743

744 745 746
	if (!kvm)
		return ERR_PTR(-ENOMEM);

747
	spin_lock_init(&kvm->mmu_lock);
V
Vegard Nossum 已提交
748
	mmgrab(current->mm);
749 750 751 752 753 754 755
	kvm->mm = current->mm;
	kvm_eventfd_init(kvm);
	mutex_init(&kvm->lock);
	mutex_init(&kvm->irq_lock);
	mutex_init(&kvm->slots_lock);
	INIT_LIST_HEAD(&kvm->devices);

756 757
	BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);

758 759 760 761 762
	if (init_srcu_struct(&kvm->srcu))
		goto out_err_no_srcu;
	if (init_srcu_struct(&kvm->irq_srcu))
		goto out_err_no_irq_srcu;

763
	refcount_set(&kvm->users_count, 1);
764
	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
765
		struct kvm_memslots *slots = kvm_alloc_memslots();
766

767
		if (!slots)
768
			goto out_err_no_arch_destroy_vm;
769
		/* Generations must be different for each address space. */
770
		slots->generation = i;
771
		rcu_assign_pointer(kvm->memslots[i], slots);
772
	}
773

M
Marcelo Tosatti 已提交
774
	for (i = 0; i < KVM_NR_BUSES; i++) {
775
		rcu_assign_pointer(kvm->buses[i],
776
			kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
777
		if (!kvm->buses[i])
778
			goto out_err_no_arch_destroy_vm;
M
Marcelo Tosatti 已提交
779
	}
780

781 782
	kvm->max_halt_poll_ns = halt_poll_ns;

783
	r = kvm_arch_init_vm(kvm, type);
784
	if (r)
785
		goto out_err_no_arch_destroy_vm;
786 787 788

	r = hardware_enable_all();
	if (r)
789
		goto out_err_no_disable;
790

791
#ifdef CONFIG_HAVE_KVM_IRQFD
792
	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
793
#endif
A
Avi Kivity 已提交
794

795
	r = kvm_init_mmu_notifier(kvm);
796 797 798 799
	if (r)
		goto out_err_no_mmu_notifier;

	r = kvm_arch_post_init_vm(kvm);
800 801 802
	if (r)
		goto out_err;

J
Junaid Shahid 已提交
803
	mutex_lock(&kvm_lock);
804
	list_add(&kvm->vm_list, &vm_list);
J
Junaid Shahid 已提交
805
	mutex_unlock(&kvm_lock);
806

807 808
	preempt_notifier_inc();

809
	return kvm;
810 811

out_err:
812 813 814 815 816
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
	if (kvm->mmu_notifier.ops)
		mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
#endif
out_err_no_mmu_notifier:
817
	hardware_disable_all();
818
out_err_no_disable:
819 820
	kvm_arch_destroy_vm(kvm);
out_err_no_arch_destroy_vm:
821
	WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
M
Marcelo Tosatti 已提交
822
	for (i = 0; i < KVM_NR_BUSES; i++)
823
		kfree(kvm_get_bus(kvm, i));
824
	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
825
		kvm_free_memslots(kvm, __kvm_memslots(kvm, i));
826 827 828 829
	cleanup_srcu_struct(&kvm->irq_srcu);
out_err_no_irq_srcu:
	cleanup_srcu_struct(&kvm->srcu);
out_err_no_srcu:
830
	kvm_arch_free_vm(kvm);
831
	mmdrop(current->mm);
832
	return ERR_PTR(r);
833 834
}

835 836
static void kvm_destroy_devices(struct kvm *kvm)
{
G
Geliang Tang 已提交
837
	struct kvm_device *dev, *tmp;
838

839 840 841 842 843
	/*
	 * We do not need to take the kvm->lock here, because nobody else
	 * has a reference to the struct kvm at this point and therefore
	 * cannot access the devices list anyhow.
	 */
G
Geliang Tang 已提交
844 845
	list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
		list_del(&dev->vm_node);
846 847 848 849
		dev->ops->destroy(dev);
	}
}

850 851
static void kvm_destroy_vm(struct kvm *kvm)
{
M
Marcelo Tosatti 已提交
852
	int i;
853 854
	struct mm_struct *mm = kvm->mm;

855
	kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
856
	kvm_destroy_vm_debugfs(kvm);
857
	kvm_arch_sync_events(kvm);
J
Junaid Shahid 已提交
858
	mutex_lock(&kvm_lock);
859
	list_del(&kvm->vm_list);
J
Junaid Shahid 已提交
860
	mutex_unlock(&kvm_lock);
861 862
	kvm_arch_pre_destroy_vm(kvm);

863
	kvm_free_irq_routing(kvm);
864
	for (i = 0; i < KVM_NR_BUSES; i++) {
865
		struct kvm_io_bus *bus = kvm_get_bus(kvm, i);
866 867 868

		if (bus)
			kvm_io_bus_destroy(bus);
869 870
		kvm->buses[i] = NULL;
	}
871
	kvm_coalesced_mmio_free(kvm);
872 873
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
874
#else
875
	kvm_arch_flush_shadow_all(kvm);
876
#endif
877
	kvm_arch_destroy_vm(kvm);
878
	kvm_destroy_devices(kvm);
879
	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
880
		kvm_free_memslots(kvm, __kvm_memslots(kvm, i));
881
	cleanup_srcu_struct(&kvm->irq_srcu);
882 883
	cleanup_srcu_struct(&kvm->srcu);
	kvm_arch_free_vm(kvm);
884
	preempt_notifier_dec();
885
	hardware_disable_all();
886
	mmdrop(mm);
887 888
}

I
Izik Eidus 已提交
889 890
void kvm_get_kvm(struct kvm *kvm)
{
891
	refcount_inc(&kvm->users_count);
I
Izik Eidus 已提交
892 893 894 895 896
}
EXPORT_SYMBOL_GPL(kvm_get_kvm);

void kvm_put_kvm(struct kvm *kvm)
{
897
	if (refcount_dec_and_test(&kvm->users_count))
I
Izik Eidus 已提交
898 899 900 901
		kvm_destroy_vm(kvm);
}
EXPORT_SYMBOL_GPL(kvm_put_kvm);

902 903 904 905 906 907 908 909 910 911 912 913
/*
 * Used to put a reference that was taken on behalf of an object associated
 * with a user-visible file descriptor, e.g. a vcpu or device, if installation
 * of the new file descriptor fails and the reference cannot be transferred to
 * its final owner.  In such cases, the caller is still actively using @kvm and
 * will fail miserably if the refcount unexpectedly hits zero.
 */
void kvm_put_kvm_no_destroy(struct kvm *kvm)
{
	WARN_ON(refcount_dec_and_test(&kvm->users_count));
}
EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
I
Izik Eidus 已提交
914

915 916 917 918
static int kvm_vm_release(struct inode *inode, struct file *filp)
{
	struct kvm *kvm = filp->private_data;

G
Gregory Haskins 已提交
919 920
	kvm_irqfd_release(kvm);

I
Izik Eidus 已提交
921
	kvm_put_kvm(kvm);
A
Avi Kivity 已提交
922 923 924
	return 0;
}

925 926
/*
 * Allocation size is twice as large as the actual dirty bitmap size.
927
 * See kvm_vm_ioctl_get_dirty_log() why this is needed.
928
 */
929
static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot)
930
{
931
	unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
932

933
	memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT);
934 935 936 937 938 939
	if (!memslot->dirty_bitmap)
		return -ENOMEM;

	return 0;
}

940
/*
941 942
 * Delete a memslot by decrementing the number of used slots and shifting all
 * other entries in the array forward one spot.
943
 */
944 945
static inline void kvm_memslot_delete(struct kvm_memslots *slots,
				      struct kvm_memory_slot *memslot)
946
{
947
	struct kvm_memory_slot *mslots = slots->memslots;
948
	int i;
949

950 951
	if (WARN_ON(slots->id_to_index[memslot->id] == -1))
		return;
952

953 954
	slots->used_slots--;

955 956 957
	if (atomic_read(&slots->lru_slot) >= slots->used_slots)
		atomic_set(&slots->lru_slot, 0);

958
	for (i = slots->id_to_index[memslot->id]; i < slots->used_slots; i++) {
959 960 961
		mslots[i] = mslots[i + 1];
		slots->id_to_index[mslots[i].id] = i;
	}
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
	mslots[i] = *memslot;
	slots->id_to_index[memslot->id] = -1;
}

/*
 * "Insert" a new memslot by incrementing the number of used slots.  Returns
 * the new slot's initial index into the memslots array.
 */
static inline int kvm_memslot_insert_back(struct kvm_memslots *slots)
{
	return slots->used_slots++;
}

/*
 * Move a changed memslot backwards in the array by shifting existing slots
 * with a higher GFN toward the front of the array.  Note, the changed memslot
 * itself is not preserved in the array, i.e. not swapped at this time, only
 * its new index into the array is tracked.  Returns the changed memslot's
 * current index into the memslots array.
 */
static inline int kvm_memslot_move_backward(struct kvm_memslots *slots,
					    struct kvm_memory_slot *memslot)
{
	struct kvm_memory_slot *mslots = slots->memslots;
	int i;

	if (WARN_ON_ONCE(slots->id_to_index[memslot->id] == -1) ||
	    WARN_ON_ONCE(!slots->used_slots))
		return -1;
991 992

	/*
993 994 995
	 * Move the target memslot backward in the array by shifting existing
	 * memslots with a higher GFN (than the target memslot) towards the
	 * front of the array.
996
	 */
997 998 999 1000 1001
	for (i = slots->id_to_index[memslot->id]; i < slots->used_slots - 1; i++) {
		if (memslot->base_gfn > mslots[i + 1].base_gfn)
			break;

		WARN_ON_ONCE(memslot->base_gfn == mslots[i + 1].base_gfn);
1002

1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
		/* Shift the next memslot forward one and update its index. */
		mslots[i] = mslots[i + 1];
		slots->id_to_index[mslots[i].id] = i;
	}
	return i;
}

/*
 * Move a changed memslot forwards in the array by shifting existing slots with
 * a lower GFN toward the back of the array.  Note, the changed memslot itself
 * is not preserved in the array, i.e. not swapped at this time, only its new
 * index into the array is tracked.  Returns the changed memslot's final index
 * into the memslots array.
 */
static inline int kvm_memslot_move_forward(struct kvm_memslots *slots,
					   struct kvm_memory_slot *memslot,
					   int start)
{
	struct kvm_memory_slot *mslots = slots->memslots;
	int i;

	for (i = start; i > 0; i--) {
		if (memslot->base_gfn < mslots[i - 1].base_gfn)
			break;

		WARN_ON_ONCE(memslot->base_gfn == mslots[i - 1].base_gfn);

		/* Shift the next memslot back one and update its index. */
		mslots[i] = mslots[i - 1];
		slots->id_to_index[mslots[i].id] = i;
	}
	return i;
}

/*
 * Re-sort memslots based on their GFN to account for an added, deleted, or
 * moved memslot.  Sorting memslots by GFN allows using a binary search during
 * memslot lookup.
 *
 * IMPORTANT: Slots are sorted from highest GFN to lowest GFN!  I.e. the entry
 * at memslots[0] has the highest GFN.
 *
 * The sorting algorithm takes advantage of having initially sorted memslots
 * and knowing the position of the changed memslot.  Sorting is also optimized
 * by not swapping the updated memslot and instead only shifting other memslots
 * and tracking the new index for the update memslot.  Only once its final
 * index is known is the updated memslot copied into its position in the array.
 *
 *  - When deleting a memslot, the deleted memslot simply needs to be moved to
 *    the end of the array.
 *
 *  - When creating a memslot, the algorithm "inserts" the new memslot at the
 *    end of the array and then it forward to its correct location.
 *
 *  - When moving a memslot, the algorithm first moves the updated memslot
 *    backward to handle the scenario where the memslot's GFN was changed to a
 *    lower value.  update_memslots() then falls through and runs the same flow
 *    as creating a memslot to move the memslot forward to handle the scenario
 *    where its GFN was changed to a higher value.
 *
 * Note, slots are sorted from highest->lowest instead of lowest->highest for
 * historical reasons.  Originally, invalid memslots where denoted by having
 * GFN=0, thus sorting from highest->lowest naturally sorted invalid memslots
 * to the end of the array.  The current algorithm uses dedicated logic to
 * delete a memslot and thus does not rely on invalid memslots having GFN=0.
 *
 * The other historical motiviation for highest->lowest was to improve the
 * performance of memslot lookup.  KVM originally used a linear search starting
 * at memslots[0].  On x86, the largest memslot usually has one of the highest,
 * if not *the* highest, GFN, as the bulk of the guest's RAM is located in a
 * single memslot above the 4gb boundary.  As the largest memslot is also the
 * most likely to be referenced, sorting it to the front of the array was
 * advantageous.  The current binary search starts from the middle of the array
 * and uses an LRU pointer to improve performance for all memslots and GFNs.
 */
static void update_memslots(struct kvm_memslots *slots,
			    struct kvm_memory_slot *memslot,
			    enum kvm_mr_change change)
{
	int i;

	if (change == KVM_MR_DELETE) {
		kvm_memslot_delete(slots, memslot);
	} else {
		if (change == KVM_MR_CREATE)
			i = kvm_memslot_insert_back(slots);
		else
			i = kvm_memslot_move_backward(slots, memslot);
		i = kvm_memslot_move_forward(slots, memslot, i);

		/*
		 * Copy the memslot to its new position in memslots and update
		 * its index accordingly.
		 */
		slots->memslots[i] = *memslot;
		slots->id_to_index[memslot->id] = i;
	}
1100 1101
}

1102
static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
1103
{
X
Xiao Guangrong 已提交
1104 1105
	u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;

1106
#ifdef __KVM_HAVE_READONLY_MEM
X
Xiao Guangrong 已提交
1107 1108 1109 1110
	valid_flags |= KVM_MEM_READONLY;
#endif

	if (mem->flags & ~valid_flags)
1111 1112 1113 1114 1115
		return -EINVAL;

	return 0;
}

1116
static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
1117
		int as_id, struct kvm_memslots *slots)
1118
{
1119
	struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
1120
	u64 gen = old_memslots->generation;
1121

1122 1123
	WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS);
	slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
1124

1125
	rcu_assign_pointer(kvm->memslots[as_id], slots);
1126
	synchronize_srcu_expedited(&kvm->srcu);
1127

1128
	/*
1129
	 * Increment the new memslot generation a second time, dropping the
M
Miaohe Lin 已提交
1130
	 * update in-progress flag and incrementing the generation based on
1131 1132 1133 1134 1135 1136
	 * the number of address spaces.  This provides a unique and easily
	 * identifiable generation number while the memslots are in flux.
	 */
	gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;

	/*
1137 1138 1139
	 * Generations must be unique even across address spaces.  We do not need
	 * a global counter for that, instead the generation space is evenly split
	 * across address spaces.  For example, with two address spaces, address
1140 1141
	 * space 0 will use generations 0, 2, 4, ... while address space 1 will
	 * use generations 1, 3, 5, ...
1142
	 */
1143
	gen += KVM_ADDRESS_SPACE_NUM;
1144

1145
	kvm_arch_memslots_updated(kvm, gen);
1146

1147
	slots->generation = gen;
1148 1149

	return old_memslots;
1150 1151
}

1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
/*
 * Note, at a minimum, the current number of used slots must be allocated, even
 * when deleting a memslot, as we need a complete duplicate of the memslots for
 * use when invalidating a memslot prior to deleting/moving the memslot.
 */
static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old,
					     enum kvm_mr_change change)
{
	struct kvm_memslots *slots;
	size_t old_size, new_size;

	old_size = sizeof(struct kvm_memslots) +
		   (sizeof(struct kvm_memory_slot) * old->used_slots);

	if (change == KVM_MR_CREATE)
		new_size = old_size + sizeof(struct kvm_memory_slot);
	else
		new_size = old_size;

	slots = kvzalloc(new_size, GFP_KERNEL_ACCOUNT);
	if (likely(slots))
		memcpy(slots, old, old_size);

	return slots;
}

1178 1179
static int kvm_set_memslot(struct kvm *kvm,
			   const struct kvm_userspace_memory_region *mem,
1180
			   struct kvm_memory_slot *old,
1181 1182 1183 1184 1185 1186 1187
			   struct kvm_memory_slot *new, int as_id,
			   enum kvm_mr_change change)
{
	struct kvm_memory_slot *slot;
	struct kvm_memslots *slots;
	int r;

1188
	slots = kvm_dup_memslots(__kvm_memslots(kvm, as_id), change);
1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236
	if (!slots)
		return -ENOMEM;

	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
		/*
		 * Note, the INVALID flag needs to be in the appropriate entry
		 * in the freshly allocated memslots, not in @old or @new.
		 */
		slot = id_to_memslot(slots, old->id);
		slot->flags |= KVM_MEMSLOT_INVALID;

		/*
		 * We can re-use the old memslots, the only difference from the
		 * newly installed memslots is the invalid flag, which will get
		 * dropped by update_memslots anyway.  We'll also revert to the
		 * old memslots if preparing the new memory region fails.
		 */
		slots = install_new_memslots(kvm, as_id, slots);

		/* From this point no new shadow pages pointing to a deleted,
		 * or moved, memslot will be created.
		 *
		 * validation of sp->gfn happens in:
		 *	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
		 *	- kvm_is_visible_gfn (mmu_check_root)
		 */
		kvm_arch_flush_shadow_memslot(kvm, slot);
	}

	r = kvm_arch_prepare_memory_region(kvm, new, mem, change);
	if (r)
		goto out_slots;

	update_memslots(slots, new, change);
	slots = install_new_memslots(kvm, as_id, slots);

	kvm_arch_commit_memory_region(kvm, mem, old, new, change);

	kvfree(slots);
	return 0;

out_slots:
	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE)
		slots = install_new_memslots(kvm, as_id, slots);
	kvfree(slots);
	return r;
}

1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253
static int kvm_delete_memslot(struct kvm *kvm,
			      const struct kvm_userspace_memory_region *mem,
			      struct kvm_memory_slot *old, int as_id)
{
	struct kvm_memory_slot new;
	int r;

	if (!old->npages)
		return -EINVAL;

	memset(&new, 0, sizeof(new));
	new.id = old->id;

	r = kvm_set_memslot(kvm, mem, old, &new, as_id, KVM_MR_DELETE);
	if (r)
		return r;

1254
	kvm_free_memslot(kvm, old);
1255 1256 1257
	return 0;
}

A
Avi Kivity 已提交
1258 1259 1260 1261 1262
/*
 * Allocate some memory and give it an address in the guest physical address
 * space.
 *
 * Discontiguous memory is allowed, mostly for framebuffers.
1263
 *
1264
 * Must be called holding kvm->slots_lock for write.
A
Avi Kivity 已提交
1265
 */
1266
int __kvm_set_memory_region(struct kvm *kvm,
1267
			    const struct kvm_userspace_memory_region *mem)
A
Avi Kivity 已提交
1268 1269
{
	struct kvm_memory_slot old, new;
1270
	struct kvm_memory_slot *tmp;
1271
	enum kvm_mr_change change;
1272 1273
	int as_id, id;
	int r;
A
Avi Kivity 已提交
1274

1275 1276
	r = check_memory_region_flags(mem);
	if (r)
1277
		return r;
1278

1279 1280 1281
	as_id = mem->slot >> 16;
	id = (u16)mem->slot;

A
Avi Kivity 已提交
1282 1283
	/* General sanity checks */
	if (mem->memory_size & (PAGE_SIZE - 1))
1284
		return -EINVAL;
A
Avi Kivity 已提交
1285
	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
1286
		return -EINVAL;
1287
	/* We can read the guest memory with __xxx_user() later on. */
1288
	if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
1289
	     !access_ok((void __user *)(unsigned long)mem->userspace_addr,
1290
			mem->memory_size))
1291
		return -EINVAL;
1292
	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
1293
		return -EINVAL;
A
Avi Kivity 已提交
1294
	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
1295
		return -EINVAL;
A
Avi Kivity 已提交
1296

1297 1298 1299 1300
	/*
	 * Make a full copy of the old memslot, the pointer will become stale
	 * when the memslots are re-sorted by update_memslots(), and the old
	 * memslot needs to be referenced after calling update_memslots(), e.g.
1301
	 * to free its resources and for arch specific behavior.
1302
	 */
1303 1304 1305 1306 1307 1308 1309 1310
	tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id);
	if (tmp) {
		old = *tmp;
		tmp = NULL;
	} else {
		memset(&old, 0, sizeof(old));
		old.id = id;
	}
1311

1312 1313 1314
	if (!mem->memory_size)
		return kvm_delete_memslot(kvm, mem, &old, as_id);

1315
	new.id = id;
1316 1317
	new.base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
	new.npages = mem->memory_size >> PAGE_SHIFT;
A
Avi Kivity 已提交
1318
	new.flags = mem->flags;
1319
	new.userspace_addr = mem->userspace_addr;
A
Avi Kivity 已提交
1320

1321 1322 1323
	if (new.npages > KVM_MEM_MAX_NR_PAGES)
		return -EINVAL;

1324 1325
	if (!old.npages) {
		change = KVM_MR_CREATE;
1326 1327
		new.dirty_bitmap = NULL;
		memset(&new.arch, 0, sizeof(new.arch));
1328 1329
	} else { /* Modify an existing slot. */
		if ((new.userspace_addr != old.userspace_addr) ||
1330
		    (new.npages != old.npages) ||
1331
		    ((new.flags ^ old.flags) & KVM_MEM_READONLY))
1332
			return -EINVAL;
1333

1334
		if (new.base_gfn != old.base_gfn)
1335 1336 1337 1338 1339
			change = KVM_MR_MOVE;
		else if (new.flags != old.flags)
			change = KVM_MR_FLAGS_ONLY;
		else /* Nothing to change. */
			return 0;
1340 1341 1342 1343

		/* Copy dirty_bitmap and arch from the current memslot. */
		new.dirty_bitmap = old.dirty_bitmap;
		memcpy(&new.arch, &old.arch, sizeof(new.arch));
1344
	}
A
Avi Kivity 已提交
1345

1346
	if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
1347
		/* Check for overlaps */
1348 1349
		kvm_for_each_memslot(tmp, __kvm_memslots(kvm, as_id)) {
			if (tmp->id == id)
1350
				continue;
1351 1352
			if (!((new.base_gfn + new.npages <= tmp->base_gfn) ||
			      (new.base_gfn >= tmp->base_gfn + tmp->npages)))
1353
				return -EEXIST;
1354
		}
A
Avi Kivity 已提交
1355 1356
	}

1357 1358 1359 1360
	/* Allocate/free page dirty bitmap as needed */
	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
		new.dirty_bitmap = NULL;
	else if (!new.dirty_bitmap) {
1361
		r = kvm_alloc_dirty_bitmap(&new);
1362 1363
		if (r)
			return r;
1364 1365 1366

		if (kvm_dirty_log_manual_protect_and_init_set(kvm))
			bitmap_set(new.dirty_bitmap, 0, new.npages);
A
Avi Kivity 已提交
1367 1368
	}

1369 1370 1371
	r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change);
	if (r)
		goto out_bitmap;
1372

1373 1374
	if (old.dirty_bitmap && !new.dirty_bitmap)
		kvm_destroy_dirty_bitmap(&old);
A
Avi Kivity 已提交
1375 1376
	return 0;

1377 1378 1379
out_bitmap:
	if (new.dirty_bitmap && !old.dirty_bitmap)
		kvm_destroy_dirty_bitmap(&new);
A
Avi Kivity 已提交
1380
	return r;
1381
}
1382 1383 1384
EXPORT_SYMBOL_GPL(__kvm_set_memory_region);

int kvm_set_memory_region(struct kvm *kvm,
1385
			  const struct kvm_userspace_memory_region *mem)
1386 1387 1388
{
	int r;

1389
	mutex_lock(&kvm->slots_lock);
1390
	r = __kvm_set_memory_region(kvm, mem);
1391
	mutex_unlock(&kvm->slots_lock);
1392 1393
	return r;
}
1394 1395
EXPORT_SYMBOL_GPL(kvm_set_memory_region);

1396 1397
static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
					  struct kvm_userspace_memory_region *mem)
1398
{
1399
	if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
1400
		return -EINVAL;
1401

1402
	return kvm_set_memory_region(kvm, mem);
A
Avi Kivity 已提交
1403 1404
}

1405
#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
1406 1407 1408 1409 1410 1411 1412 1413 1414
/**
 * kvm_get_dirty_log - get a snapshot of dirty pages
 * @kvm:	pointer to kvm instance
 * @log:	slot id and address to which we copy the log
 * @is_dirty:	set to '1' if any dirty pages were found
 * @memslot:	set to the associated memslot, always valid on success
 */
int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
		      int *is_dirty, struct kvm_memory_slot **memslot)
A
Avi Kivity 已提交
1415
{
1416
	struct kvm_memslots *slots;
1417
	int i, as_id, id;
1418
	unsigned long n;
A
Avi Kivity 已提交
1419 1420
	unsigned long any = 0;

1421 1422 1423
	*memslot = NULL;
	*is_dirty = 0;

1424 1425 1426
	as_id = log->slot >> 16;
	id = (u16)log->slot;
	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1427
		return -EINVAL;
A
Avi Kivity 已提交
1428

1429
	slots = __kvm_memslots(kvm, as_id);
1430
	*memslot = id_to_memslot(slots, id);
1431
	if (!(*memslot) || !(*memslot)->dirty_bitmap)
1432
		return -ENOENT;
A
Avi Kivity 已提交
1433

1434 1435 1436
	kvm_arch_sync_dirty_log(kvm, *memslot);

	n = kvm_dirty_bitmap_bytes(*memslot);
A
Avi Kivity 已提交
1437

1438
	for (i = 0; !any && i < n/sizeof(long); ++i)
1439
		any = (*memslot)->dirty_bitmap[i];
A
Avi Kivity 已提交
1440

1441
	if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
1442
		return -EFAULT;
A
Avi Kivity 已提交
1443

1444 1445
	if (any)
		*is_dirty = 1;
1446
	return 0;
A
Avi Kivity 已提交
1447
}
1448
EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
A
Avi Kivity 已提交
1449

1450
#else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
1451
/**
J
Jiang Biao 已提交
1452
 * kvm_get_dirty_log_protect - get a snapshot of dirty pages
1453
 *	and reenable dirty page tracking for the corresponding pages.
1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471
 * @kvm:	pointer to kvm instance
 * @log:	slot id and address to which we copy the log
 *
 * We need to keep it in mind that VCPU threads can write to the bitmap
 * concurrently. So, to avoid losing track of dirty pages we keep the
 * following order:
 *
 *    1. Take a snapshot of the bit and clear it if needed.
 *    2. Write protect the corresponding page.
 *    3. Copy the snapshot to the userspace.
 *    4. Upon return caller flushes TLB's if needed.
 *
 * Between 2 and 4, the guest may write to the page using the remaining TLB
 * entry.  This is not a problem because the page is reported dirty using
 * the snapshot taken before and step 4 ensures that writes done after
 * exiting to userspace will be logged for the next call.
 *
 */
1472
static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log)
1473
{
1474
	struct kvm_memslots *slots;
1475
	struct kvm_memory_slot *memslot;
1476
	int i, as_id, id;
1477 1478 1479
	unsigned long n;
	unsigned long *dirty_bitmap;
	unsigned long *dirty_bitmap_buffer;
1480
	bool flush;
1481

1482 1483 1484
	as_id = log->slot >> 16;
	id = (u16)log->slot;
	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1485
		return -EINVAL;
1486

1487 1488
	slots = __kvm_memslots(kvm, as_id);
	memslot = id_to_memslot(slots, id);
1489 1490
	if (!memslot || !memslot->dirty_bitmap)
		return -ENOENT;
1491 1492 1493

	dirty_bitmap = memslot->dirty_bitmap;

1494 1495
	kvm_arch_sync_dirty_log(kvm, memslot);

1496
	n = kvm_dirty_bitmap_bytes(memslot);
1497
	flush = false;
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
	if (kvm->manual_dirty_log_protect) {
		/*
		 * Unlike kvm_get_dirty_log, we always return false in *flush,
		 * because no flush is needed until KVM_CLEAR_DIRTY_LOG.  There
		 * is some code duplication between this function and
		 * kvm_get_dirty_log, but hopefully all architecture
		 * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
		 * can be eliminated.
		 */
		dirty_bitmap_buffer = dirty_bitmap;
	} else {
		dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
		memset(dirty_bitmap_buffer, 0, n);
1511

1512 1513 1514 1515
		spin_lock(&kvm->mmu_lock);
		for (i = 0; i < n / sizeof(long); i++) {
			unsigned long mask;
			gfn_t offset;
1516

1517 1518 1519
			if (!dirty_bitmap[i])
				continue;

1520
			flush = true;
1521 1522 1523
			mask = xchg(&dirty_bitmap[i], 0);
			dirty_bitmap_buffer[i] = mask;

1524 1525 1526
			offset = i * BITS_PER_LONG;
			kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
								offset, mask);
1527 1528 1529 1530
		}
		spin_unlock(&kvm->mmu_lock);
	}

1531 1532 1533
	if (flush)
		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

1534 1535 1536 1537
	if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
		return -EFAULT;
	return 0;
}
1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570


/**
 * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
 * @kvm: kvm instance
 * @log: slot id and address to which we copy the log
 *
 * Steps 1-4 below provide general overview of dirty page logging. See
 * kvm_get_dirty_log_protect() function description for additional details.
 *
 * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
 * always flush the TLB (step 4) even if previous step failed  and the dirty
 * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
 * does not preclude user space subsequent dirty log read. Flushing TLB ensures
 * writes will be marked dirty for next log read.
 *
 *   1. Take a snapshot of the bit and clear it if needed.
 *   2. Write protect the corresponding page.
 *   3. Copy the snapshot to the userspace.
 *   4. Flush TLB's if needed.
 */
static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
				      struct kvm_dirty_log *log)
{
	int r;

	mutex_lock(&kvm->slots_lock);

	r = kvm_get_dirty_log_protect(kvm, log);

	mutex_unlock(&kvm->slots_lock);
	return r;
}
1571 1572 1573 1574 1575 1576 1577

/**
 * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
 *	and reenable dirty page tracking for the corresponding pages.
 * @kvm:	pointer to kvm instance
 * @log:	slot id and address from which to fetch the bitmap of dirty pages
 */
1578 1579
static int kvm_clear_dirty_log_protect(struct kvm *kvm,
				       struct kvm_clear_dirty_log *log)
1580 1581 1582
{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;
1583
	int as_id, id;
1584
	gfn_t offset;
1585
	unsigned long i, n;
1586 1587
	unsigned long *dirty_bitmap;
	unsigned long *dirty_bitmap_buffer;
1588
	bool flush;
1589 1590 1591 1592 1593 1594

	as_id = log->slot >> 16;
	id = (u16)log->slot;
	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
		return -EINVAL;

1595
	if (log->first_page & 63)
1596 1597 1598 1599
		return -EINVAL;

	slots = __kvm_memslots(kvm, as_id);
	memslot = id_to_memslot(slots, id);
1600 1601
	if (!memslot || !memslot->dirty_bitmap)
		return -ENOENT;
1602 1603 1604

	dirty_bitmap = memslot->dirty_bitmap;

1605
	n = ALIGN(log->num_pages, BITS_PER_LONG) / 8;
1606 1607

	if (log->first_page > memslot->npages ||
1608 1609 1610
	    log->num_pages > memslot->npages - log->first_page ||
	    (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63)))
	    return -EINVAL;
1611

1612 1613 1614
	kvm_arch_sync_dirty_log(kvm, memslot);

	flush = false;
1615 1616 1617
	dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
	if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n))
		return -EFAULT;
1618

1619
	spin_lock(&kvm->mmu_lock);
1620 1621
	for (offset = log->first_page, i = offset / BITS_PER_LONG,
		 n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--;
1622 1623 1624 1625
	     i++, offset += BITS_PER_LONG) {
		unsigned long mask = *dirty_bitmap_buffer++;
		atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
		if (!mask)
1626 1627
			continue;

1628
		mask &= atomic_long_fetch_andnot(mask, p);
1629

1630 1631 1632 1633 1634 1635
		/*
		 * mask contains the bits that really have been cleared.  This
		 * never includes any bits beyond the length of the memslot (if
		 * the length is not aligned to 64 pages), therefore it is not
		 * a problem if userspace sets them in log->dirty_bitmap.
		*/
1636
		if (mask) {
1637
			flush = true;
1638 1639 1640
			kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
								offset, mask);
		}
1641 1642
	}
	spin_unlock(&kvm->mmu_lock);
1643

1644 1645 1646
	if (flush)
		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

1647
	return 0;
1648
}
1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662

static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
					struct kvm_clear_dirty_log *log)
{
	int r;

	mutex_lock(&kvm->slots_lock);

	r = kvm_clear_dirty_log_protect(kvm, log);

	mutex_unlock(&kvm->slots_lock);
	return r;
}
#endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
1663

1664 1665 1666 1667
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
	return __gfn_to_memslot(kvm_memslots(kvm), gfn);
}
A
Avi Kivity 已提交
1668
EXPORT_SYMBOL_GPL(gfn_to_memslot);
A
Avi Kivity 已提交
1669

1670 1671 1672 1673
struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
{
	return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
}
1674
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
1675

1676
bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1677
{
1678
	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
1679

1680
	return kvm_is_visible_memslot(memslot);
1681 1682 1683
}
EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);

1684 1685 1686 1687 1688 1689 1690 1691
bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
	struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);

	return kvm_is_visible_memslot(memslot);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn);

1692
unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn)
J
Joerg Roedel 已提交
1693 1694 1695 1696 1697 1698
{
	struct vm_area_struct *vma;
	unsigned long addr, size;

	size = PAGE_SIZE;

1699
	addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL);
J
Joerg Roedel 已提交
1700 1701 1702
	if (kvm_is_error_hva(addr))
		return PAGE_SIZE;

1703
	mmap_read_lock(current->mm);
J
Joerg Roedel 已提交
1704 1705 1706 1707 1708 1709 1710
	vma = find_vma(current->mm, addr);
	if (!vma)
		goto out;

	size = vma_kernel_pagesize(vma);

out:
1711
	mmap_read_unlock(current->mm);
J
Joerg Roedel 已提交
1712 1713 1714 1715

	return size;
}

X
Xiao Guangrong 已提交
1716 1717 1718 1719 1720 1721 1722
static bool memslot_is_readonly(struct kvm_memory_slot *slot)
{
	return slot->flags & KVM_MEM_READONLY;
}

static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
				       gfn_t *nr_pages, bool write)
I
Izik Eidus 已提交
1723
{
1724
	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
X
Xiao Guangrong 已提交
1725
		return KVM_HVA_ERR_BAD;
1726

X
Xiao Guangrong 已提交
1727 1728
	if (memslot_is_readonly(slot) && write)
		return KVM_HVA_ERR_RO_BAD;
1729 1730 1731 1732

	if (nr_pages)
		*nr_pages = slot->npages - (gfn - slot->base_gfn);

X
Xiao Guangrong 已提交
1733
	return __gfn_to_hva_memslot(slot, gfn);
I
Izik Eidus 已提交
1734
}
1735

X
Xiao Guangrong 已提交
1736 1737 1738 1739
static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
				     gfn_t *nr_pages)
{
	return __gfn_to_hva_many(slot, gfn, nr_pages, true);
I
Izik Eidus 已提交
1740
}
1741

X
Xiao Guangrong 已提交
1742
unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
1743
					gfn_t gfn)
X
Xiao Guangrong 已提交
1744 1745 1746 1747 1748
{
	return gfn_to_hva_many(slot, gfn, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);

1749 1750
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
{
1751
	return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1752
}
1753
EXPORT_SYMBOL_GPL(gfn_to_hva);
I
Izik Eidus 已提交
1754

1755 1756 1757 1758 1759 1760
unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
{
	return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);

1761
/*
1762 1763 1764 1765 1766 1767
 * Return the hva of a @gfn and the R/W attribute if possible.
 *
 * @slot: the kvm_memory_slot which contains @gfn
 * @gfn: the gfn to be translated
 * @writable: used to return the read/write attribute of the @slot if the hva
 * is valid and @writable is not NULL
1768
 */
1769 1770
unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
				      gfn_t gfn, bool *writable)
1771
{
1772 1773 1774
	unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);

	if (!kvm_is_error_hva(hva) && writable)
1775 1776
		*writable = !memslot_is_readonly(slot);

1777
	return hva;
1778 1779
}

1780 1781 1782 1783 1784 1785 1786
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
{
	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);

	return gfn_to_hva_memslot_prot(slot, gfn, writable);
}

1787 1788 1789 1790 1791 1792 1793
unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
{
	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);

	return gfn_to_hva_memslot_prot(slot, gfn, writable);
}

1794 1795
static inline int check_user_page_hwpoison(unsigned long addr)
{
L
Lorenzo Stoakes 已提交
1796
	int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
1797

L
Lorenzo Stoakes 已提交
1798
	rc = get_user_pages(addr, 1, flags, NULL, NULL);
1799 1800 1801
	return rc == -EHWPOISON;
}

X
Xiao Guangrong 已提交
1802
/*
1803 1804
 * The fast path to get the writable pfn which will be stored in @pfn,
 * true indicates success, otherwise false is returned.  It's also the
M
Miaohe Lin 已提交
1805
 * only part that runs if we can in atomic context.
X
Xiao Guangrong 已提交
1806
 */
1807 1808
static bool hva_to_pfn_fast(unsigned long addr, bool write_fault,
			    bool *writable, kvm_pfn_t *pfn)
A
Avi Kivity 已提交
1809
{
1810
	struct page *page[1];
A
Avi Kivity 已提交
1811

1812 1813 1814 1815 1816 1817 1818
	/*
	 * Fast pin a writable pfn only if it is a write fault request
	 * or the caller allows to map a writable pfn for a read fault
	 * request.
	 */
	if (!(write_fault || writable))
		return false;
1819

1820
	if (get_user_page_fast_only(addr, FOLL_WRITE, page)) {
X
Xiao Guangrong 已提交
1821
		*pfn = page_to_pfn(page[0]);
1822

X
Xiao Guangrong 已提交
1823 1824 1825 1826
		if (writable)
			*writable = true;
		return true;
	}
1827

X
Xiao Guangrong 已提交
1828 1829
	return false;
}
1830

X
Xiao Guangrong 已提交
1831 1832 1833 1834 1835
/*
 * The slow path to get the pfn of the specified host virtual address,
 * 1 indicates success, -errno is returned if error is detected.
 */
static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
D
Dan Williams 已提交
1836
			   bool *writable, kvm_pfn_t *pfn)
X
Xiao Guangrong 已提交
1837
{
1838 1839
	unsigned int flags = FOLL_HWPOISON;
	struct page *page;
X
Xiao Guangrong 已提交
1840
	int npages = 0;
1841

X
Xiao Guangrong 已提交
1842 1843 1844 1845 1846
	might_sleep();

	if (writable)
		*writable = write_fault;

1847 1848 1849 1850
	if (write_fault)
		flags |= FOLL_WRITE;
	if (async)
		flags |= FOLL_NOWAIT;
1851

1852
	npages = get_user_pages_unlocked(addr, 1, &page, flags);
X
Xiao Guangrong 已提交
1853 1854 1855 1856
	if (npages != 1)
		return npages;

	/* map read fault as writable if possible */
1857
	if (unlikely(!write_fault) && writable) {
1858
		struct page *wpage;
X
Xiao Guangrong 已提交
1859

1860
		if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) {
X
Xiao Guangrong 已提交
1861
			*writable = true;
1862 1863
			put_page(page);
			page = wpage;
1864
		}
1865
	}
1866
	*pfn = page_to_pfn(page);
X
Xiao Guangrong 已提交
1867 1868
	return npages;
}
I
Izik Eidus 已提交
1869

X
Xiao Guangrong 已提交
1870 1871 1872 1873
static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
{
	if (unlikely(!(vma->vm_flags & VM_READ)))
		return false;
1874

X
Xiao Guangrong 已提交
1875 1876
	if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
		return false;
1877

X
Xiao Guangrong 已提交
1878 1879
	return true;
}
1880

1881 1882
static int hva_to_pfn_remapped(struct vm_area_struct *vma,
			       unsigned long addr, bool *async,
1883 1884
			       bool write_fault, bool *writable,
			       kvm_pfn_t *p_pfn)
1885
{
1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898
	unsigned long pfn;
	int r;

	r = follow_pfn(vma, addr, &pfn);
	if (r) {
		/*
		 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
		 * not call the fault handler, so do it here.
		 */
		bool unlocked = false;
		r = fixup_user_fault(current, current->mm, addr,
				     (write_fault ? FAULT_FLAG_WRITE : 0),
				     &unlocked);
1899 1900
		if (unlocked)
			return -EAGAIN;
1901 1902 1903 1904 1905 1906 1907 1908 1909
		if (r)
			return r;

		r = follow_pfn(vma, addr, &pfn);
		if (r)
			return r;

	}

1910 1911
	if (writable)
		*writable = true;
1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926

	/*
	 * Get a reference here because callers of *hva_to_pfn* and
	 * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
	 * returned pfn.  This is only needed if the VMA has VM_MIXEDMAP
	 * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will
	 * simply do nothing for reserved pfns.
	 *
	 * Whoever called remap_pfn_range is also going to call e.g.
	 * unmap_mapping_range before the underlying pages are freed,
	 * causing a call to our MMU notifier.
	 */ 
	kvm_get_pfn(pfn);

	*p_pfn = pfn;
1927 1928 1929
	return 0;
}

1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943
/*
 * Pin guest page in memory and return its pfn.
 * @addr: host virtual address which maps memory to the guest
 * @atomic: whether this function can sleep
 * @async: whether this function need to wait IO complete if the
 *         host page is not in the memory
 * @write_fault: whether we should get a writable host page
 * @writable: whether it allows to map a writable host page for !@write_fault
 *
 * The function will map a writable host page for these two cases:
 * 1): @write_fault = true
 * 2): @write_fault = false && @writable, @writable will tell the caller
 *     whether the mapping is writable.
 */
D
Dan Williams 已提交
1944
static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
X
Xiao Guangrong 已提交
1945 1946 1947
			bool write_fault, bool *writable)
{
	struct vm_area_struct *vma;
D
Dan Williams 已提交
1948
	kvm_pfn_t pfn = 0;
1949
	int npages, r;
1950

X
Xiao Guangrong 已提交
1951 1952
	/* we can do it either atomically or asynchronously, not both */
	BUG_ON(atomic && async);
1953

1954
	if (hva_to_pfn_fast(addr, write_fault, writable, &pfn))
X
Xiao Guangrong 已提交
1955 1956 1957 1958 1959 1960 1961 1962
		return pfn;

	if (atomic)
		return KVM_PFN_ERR_FAULT;

	npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
	if (npages == 1)
		return pfn;
1963

1964
	mmap_read_lock(current->mm);
X
Xiao Guangrong 已提交
1965 1966 1967 1968 1969 1970
	if (npages == -EHWPOISON ||
	      (!async && check_user_page_hwpoison(addr))) {
		pfn = KVM_PFN_ERR_HWPOISON;
		goto exit;
	}

1971
retry:
X
Xiao Guangrong 已提交
1972 1973 1974 1975
	vma = find_vma_intersection(current->mm, addr, addr + 1);

	if (vma == NULL)
		pfn = KVM_PFN_ERR_FAULT;
1976
	else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
1977
		r = hva_to_pfn_remapped(vma, addr, async, write_fault, writable, &pfn);
1978 1979
		if (r == -EAGAIN)
			goto retry;
1980 1981
		if (r < 0)
			pfn = KVM_PFN_ERR_FAULT;
X
Xiao Guangrong 已提交
1982
	} else {
X
Xiao Guangrong 已提交
1983
		if (async && vma_is_valid(vma, write_fault))
X
Xiao Guangrong 已提交
1984 1985 1986 1987
			*async = true;
		pfn = KVM_PFN_ERR_FAULT;
	}
exit:
1988
	mmap_read_unlock(current->mm);
1989
	return pfn;
1990 1991
}

D
Dan Williams 已提交
1992 1993 1994
kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
			       bool atomic, bool *async, bool write_fault,
			       bool *writable)
1995
{
X
Xiao Guangrong 已提交
1996 1997
	unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);

1998 1999 2000
	if (addr == KVM_HVA_ERR_RO_BAD) {
		if (writable)
			*writable = false;
X
Xiao Guangrong 已提交
2001
		return KVM_PFN_ERR_RO_FAULT;
2002
	}
X
Xiao Guangrong 已提交
2003

2004 2005 2006
	if (kvm_is_error_hva(addr)) {
		if (writable)
			*writable = false;
2007
		return KVM_PFN_NOSLOT;
2008
	}
X
Xiao Guangrong 已提交
2009 2010 2011 2012 2013 2014 2015 2016 2017

	/* Do not map writable pfn in the readonly memslot. */
	if (writable && memslot_is_readonly(slot)) {
		*writable = false;
		writable = NULL;
	}

	return hva_to_pfn(addr, atomic, async, write_fault,
			  writable);
2018
}
2019
EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
2020

D
Dan Williams 已提交
2021
kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
2022 2023
		      bool *writable)
{
P
Paolo Bonzini 已提交
2024 2025
	return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
				    write_fault, writable);
2026 2027 2028
}
EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);

D
Dan Williams 已提交
2029
kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
2030
{
X
Xiao Guangrong 已提交
2031
	return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
2032
}
P
Paolo Bonzini 已提交
2033
EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
2034

D
Dan Williams 已提交
2035
kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
2036
{
X
Xiao Guangrong 已提交
2037
	return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
2038
}
2039
EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
2040

D
Dan Williams 已提交
2041
kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
2042 2043 2044 2045 2046
{
	return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);

D
Dan Williams 已提交
2047
kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
P
Paolo Bonzini 已提交
2048 2049 2050 2051 2052
{
	return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);

D
Dan Williams 已提交
2053
kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
2054 2055 2056 2057 2058
{
	return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);

2059 2060
int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
			    struct page **pages, int nr_pages)
2061 2062
{
	unsigned long addr;
2063
	gfn_t entry = 0;
2064

2065
	addr = gfn_to_hva_many(slot, gfn, &entry);
2066 2067 2068 2069 2070 2071
	if (kvm_is_error_hva(addr))
		return -1;

	if (entry < nr_pages)
		return 0;

2072
	return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages);
2073 2074 2075
}
EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);

D
Dan Williams 已提交
2076
static struct page *kvm_pfn_to_page(kvm_pfn_t pfn)
X
Xiao Guangrong 已提交
2077
{
2078
	if (is_error_noslot_pfn(pfn))
2079
		return KVM_ERR_PTR_BAD_PAGE;
X
Xiao Guangrong 已提交
2080

2081
	if (kvm_is_reserved_pfn(pfn)) {
2082
		WARN_ON(1);
2083
		return KVM_ERR_PTR_BAD_PAGE;
2084
	}
X
Xiao Guangrong 已提交
2085 2086 2087 2088

	return pfn_to_page(pfn);
}

2089 2090
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
D
Dan Williams 已提交
2091
	kvm_pfn_t pfn;
2092 2093 2094

	pfn = gfn_to_pfn(kvm, gfn);

X
Xiao Guangrong 已提交
2095
	return kvm_pfn_to_page(pfn);
A
Avi Kivity 已提交
2096 2097 2098
}
EXPORT_SYMBOL_GPL(gfn_to_page);

2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
void kvm_release_pfn(kvm_pfn_t pfn, bool dirty, struct gfn_to_pfn_cache *cache)
{
	if (pfn == 0)
		return;

	if (cache)
		cache->pfn = cache->gfn = 0;

	if (dirty)
		kvm_release_pfn_dirty(pfn);
	else
		kvm_release_pfn_clean(pfn);
}

static void kvm_cache_gfn_to_pfn(struct kvm_memory_slot *slot, gfn_t gfn,
				 struct gfn_to_pfn_cache *cache, u64 gen)
{
	kvm_release_pfn(cache->pfn, cache->dirty, cache);

	cache->pfn = gfn_to_pfn_memslot(slot, gfn);
	cache->gfn = gfn;
	cache->dirty = false;
	cache->generation = gen;
}

2124
static int __kvm_map_gfn(struct kvm_memslots *slots, gfn_t gfn,
2125 2126 2127
			 struct kvm_host_map *map,
			 struct gfn_to_pfn_cache *cache,
			 bool atomic)
2128 2129 2130 2131
{
	kvm_pfn_t pfn;
	void *hva = NULL;
	struct page *page = KVM_UNMAPPED_PAGE;
2132
	struct kvm_memory_slot *slot = __gfn_to_memslot(slots, gfn);
2133
	u64 gen = slots->generation;
2134 2135 2136 2137

	if (!map)
		return -EINVAL;

2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150
	if (cache) {
		if (!cache->pfn || cache->gfn != gfn ||
			cache->generation != gen) {
			if (atomic)
				return -EAGAIN;
			kvm_cache_gfn_to_pfn(slot, gfn, cache, gen);
		}
		pfn = cache->pfn;
	} else {
		if (atomic)
			return -EAGAIN;
		pfn = gfn_to_pfn_memslot(slot, gfn);
	}
2151 2152 2153 2154 2155
	if (is_error_noslot_pfn(pfn))
		return -EINVAL;

	if (pfn_valid(pfn)) {
		page = pfn_to_page(pfn);
2156 2157 2158 2159
		if (atomic)
			hva = kmap_atomic(page);
		else
			hva = kmap(page);
P
Paolo Bonzini 已提交
2160
#ifdef CONFIG_HAS_IOMEM
2161
	} else if (!atomic) {
2162
		hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB);
2163 2164
	} else {
		return -EINVAL;
P
Paolo Bonzini 已提交
2165
#endif
2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178
	}

	if (!hva)
		return -EFAULT;

	map->page = page;
	map->hva = hva;
	map->pfn = pfn;
	map->gfn = gfn;

	return 0;
}

2179 2180
int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map,
		struct gfn_to_pfn_cache *cache, bool atomic)
2181
{
2182 2183
	return __kvm_map_gfn(kvm_memslots(vcpu->kvm), gfn, map,
			cache, atomic);
2184 2185 2186
}
EXPORT_SYMBOL_GPL(kvm_map_gfn);

2187 2188
int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map)
{
2189 2190
	return __kvm_map_gfn(kvm_vcpu_memslots(vcpu), gfn, map,
		NULL, false);
2191 2192 2193
}
EXPORT_SYMBOL_GPL(kvm_vcpu_map);

2194
static void __kvm_unmap_gfn(struct kvm_memory_slot *memslot,
2195 2196 2197
			struct kvm_host_map *map,
			struct gfn_to_pfn_cache *cache,
			bool dirty, bool atomic)
2198 2199 2200 2201 2202 2203 2204
{
	if (!map)
		return;

	if (!map->hva)
		return;

2205 2206 2207 2208 2209 2210
	if (map->page != KVM_UNMAPPED_PAGE) {
		if (atomic)
			kunmap_atomic(map->hva);
		else
			kunmap(map->page);
	}
2211
#ifdef CONFIG_HAS_IOMEM
2212
	else if (!atomic)
2213
		memunmap(map->hva);
2214 2215
	else
		WARN_ONCE(1, "Unexpected unmapping in atomic context");
2216
#endif
2217

2218
	if (dirty)
2219
		mark_page_dirty_in_slot(memslot, map->gfn);
2220 2221 2222 2223 2224

	if (cache)
		cache->dirty |= dirty;
	else
		kvm_release_pfn(map->pfn, dirty, NULL);
2225 2226 2227 2228

	map->hva = NULL;
	map->page = NULL;
}
2229

2230 2231
int kvm_unmap_gfn(struct kvm_vcpu *vcpu, struct kvm_host_map *map, 
		  struct gfn_to_pfn_cache *cache, bool dirty, bool atomic)
2232
{
2233 2234
	__kvm_unmap_gfn(gfn_to_memslot(vcpu->kvm, map->gfn), map,
			cache, dirty, atomic);
2235 2236 2237 2238 2239 2240
	return 0;
}
EXPORT_SYMBOL_GPL(kvm_unmap_gfn);

void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty)
{
2241 2242
	__kvm_unmap_gfn(kvm_vcpu_gfn_to_memslot(vcpu, map->gfn), map, NULL,
			dirty, false);
2243
}
2244 2245
EXPORT_SYMBOL_GPL(kvm_vcpu_unmap);

2246 2247
struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
{
D
Dan Williams 已提交
2248
	kvm_pfn_t pfn;
2249 2250 2251 2252 2253 2254 2255

	pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);

	return kvm_pfn_to_page(pfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);

2256 2257
void kvm_release_page_clean(struct page *page)
{
2258 2259
	WARN_ON(is_error_page(page));

2260
	kvm_release_pfn_clean(page_to_pfn(page));
2261 2262 2263
}
EXPORT_SYMBOL_GPL(kvm_release_page_clean);

D
Dan Williams 已提交
2264
void kvm_release_pfn_clean(kvm_pfn_t pfn)
2265
{
2266
	if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
2267
		put_page(pfn_to_page(pfn));
2268 2269 2270
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);

2271
void kvm_release_page_dirty(struct page *page)
2272
{
X
Xiao Guangrong 已提交
2273 2274
	WARN_ON(is_error_page(page));

2275 2276 2277 2278
	kvm_release_pfn_dirty(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_dirty);

2279
void kvm_release_pfn_dirty(kvm_pfn_t pfn)
2280 2281 2282 2283
{
	kvm_set_pfn_dirty(pfn);
	kvm_release_pfn_clean(pfn);
}
2284
EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
2285

D
Dan Williams 已提交
2286
void kvm_set_pfn_dirty(kvm_pfn_t pfn)
2287
{
2288 2289
	if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn))
		SetPageDirty(pfn_to_page(pfn));
2290
}
2291 2292
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);

D
Dan Williams 已提交
2293
void kvm_set_pfn_accessed(kvm_pfn_t pfn)
2294
{
2295
	if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn))
2296
		mark_page_accessed(pfn_to_page(pfn));
2297 2298 2299
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);

D
Dan Williams 已提交
2300
void kvm_get_pfn(kvm_pfn_t pfn)
2301
{
2302
	if (!kvm_is_reserved_pfn(pfn))
2303
		get_page(pfn_to_page(pfn));
2304 2305
}
EXPORT_SYMBOL_GPL(kvm_get_pfn);
2306

2307 2308 2309 2310 2311 2312 2313 2314
static int next_segment(unsigned long len, int offset)
{
	if (len > PAGE_SIZE - offset)
		return PAGE_SIZE - offset;
	else
		return len;
}

2315 2316
static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
				 void *data, int offset, int len)
2317
{
2318 2319
	int r;
	unsigned long addr;
2320

2321
	addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
2322 2323
	if (kvm_is_error_hva(addr))
		return -EFAULT;
2324
	r = __copy_from_user(data, (void __user *)addr + offset, len);
2325
	if (r)
2326 2327 2328
		return -EFAULT;
	return 0;
}
2329 2330 2331 2332 2333 2334 2335 2336

int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
			int len)
{
	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);

	return __kvm_read_guest_page(slot, gfn, data, offset, len);
}
2337 2338
EXPORT_SYMBOL_GPL(kvm_read_guest_page);

2339 2340 2341 2342 2343 2344 2345 2346 2347
int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
			     int offset, int len)
{
	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);

	return __kvm_read_guest_page(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);

2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
	int seg;
	int offset = offset_in_page(gpa);
	int ret;

	while ((seg = next_segment(len, offset)) != 0) {
		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
		if (ret < 0)
			return ret;
		offset = 0;
		len -= seg;
		data += seg;
		++gfn;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(kvm_read_guest);

2368
int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
2369 2370
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
2371
	int seg;
2372
	int offset = offset_in_page(gpa);
2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386
	int ret;

	while ((seg = next_segment(len, offset)) != 0) {
		ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
		if (ret < 0)
			return ret;
		offset = 0;
		len -= seg;
		data += seg;
		++gfn;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
2387

2388 2389 2390 2391 2392 2393 2394
static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
			           void *data, int offset, unsigned long len)
{
	int r;
	unsigned long addr;

	addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
2395 2396
	if (kvm_is_error_hva(addr))
		return -EFAULT;
2397
	pagefault_disable();
2398
	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
2399
	pagefault_enable();
2400 2401 2402 2403 2404
	if (r)
		return -EFAULT;
	return 0;
}

2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
			       void *data, unsigned long len)
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
	int offset = offset_in_page(gpa);

	return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);

static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn,
			          const void *data, int offset, int len)
2418
{
2419 2420
	int r;
	unsigned long addr;
2421

2422
	addr = gfn_to_hva_memslot(memslot, gfn);
2423 2424
	if (kvm_is_error_hva(addr))
		return -EFAULT;
2425
	r = __copy_to_user((void __user *)addr + offset, data, len);
2426
	if (r)
2427
		return -EFAULT;
2428
	mark_page_dirty_in_slot(memslot, gfn);
2429 2430
	return 0;
}
2431 2432 2433 2434 2435 2436 2437 2438

int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
			 const void *data, int offset, int len)
{
	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);

	return __kvm_write_guest_page(slot, gfn, data, offset, len);
}
2439 2440
EXPORT_SYMBOL_GPL(kvm_write_guest_page);

2441 2442 2443 2444 2445 2446 2447 2448 2449
int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
			      const void *data, int offset, int len)
{
	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);

	return __kvm_write_guest_page(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);

2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
		    unsigned long len)
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
	int seg;
	int offset = offset_in_page(gpa);
	int ret;

	while ((seg = next_segment(len, offset)) != 0) {
		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
		if (ret < 0)
			return ret;
		offset = 0;
		len -= seg;
		data += seg;
		++gfn;
	}
	return 0;
}
2469
EXPORT_SYMBOL_GPL(kvm_write_guest);
2470

2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491
int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
		         unsigned long len)
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
	int seg;
	int offset = offset_in_page(gpa);
	int ret;

	while ((seg = next_segment(len, offset)) != 0) {
		ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
		if (ret < 0)
			return ret;
		offset = 0;
		len -= seg;
		data += seg;
		++gfn;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);

2492 2493 2494
static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
				       struct gfn_to_hva_cache *ghc,
				       gpa_t gpa, unsigned long len)
2495 2496
{
	int offset = offset_in_page(gpa);
2497 2498 2499 2500
	gfn_t start_gfn = gpa >> PAGE_SHIFT;
	gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
	gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
	gfn_t nr_pages_avail;
2501

2502
	/* Update ghc->generation before performing any error checks. */
2503
	ghc->generation = slots->generation;
2504 2505 2506 2507 2508

	if (start_gfn > end_gfn) {
		ghc->hva = KVM_HVA_ERR_BAD;
		return -EINVAL;
	}
2509 2510 2511 2512 2513

	/*
	 * If the requested region crosses two memslots, we still
	 * verify that the entire region is valid here.
	 */
2514
	for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) {
2515 2516 2517 2518
		ghc->memslot = __gfn_to_memslot(slots, start_gfn);
		ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
					   &nr_pages_avail);
		if (kvm_is_error_hva(ghc->hva))
2519
			return -EFAULT;
2520 2521 2522
	}

	/* Use the slow path for cross page reads and writes. */
2523
	if (nr_pages_needed == 1)
2524
		ghc->hva += offset;
2525
	else
2526
		ghc->memslot = NULL;
2527

2528 2529 2530
	ghc->gpa = gpa;
	ghc->len = len;
	return 0;
2531
}
2532

2533
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
2534 2535
			      gpa_t gpa, unsigned long len)
{
2536
	struct kvm_memslots *slots = kvm_memslots(kvm);
2537 2538
	return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
}
2539
EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
2540

2541
int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
2542 2543
				  void *data, unsigned int offset,
				  unsigned long len)
2544
{
2545
	struct kvm_memslots *slots = kvm_memslots(kvm);
2546
	int r;
2547
	gpa_t gpa = ghc->gpa + offset;
2548

2549
	BUG_ON(len + offset > ghc->len);
2550

2551 2552 2553 2554
	if (slots->generation != ghc->generation) {
		if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
			return -EFAULT;
	}
2555

2556 2557 2558
	if (kvm_is_error_hva(ghc->hva))
		return -EFAULT;

2559 2560 2561
	if (unlikely(!ghc->memslot))
		return kvm_write_guest(kvm, gpa, data, len);

2562
	r = __copy_to_user((void __user *)ghc->hva + offset, data, len);
2563 2564
	if (r)
		return -EFAULT;
2565
	mark_page_dirty_in_slot(ghc->memslot, gpa >> PAGE_SHIFT);
2566 2567 2568

	return 0;
}
2569
EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
2570

2571 2572
int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
			   void *data, unsigned long len)
2573
{
2574
	return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
2575
}
2576
EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
2577

2578 2579 2580
int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
				 void *data, unsigned int offset,
				 unsigned long len)
2581
{
2582
	struct kvm_memslots *slots = kvm_memslots(kvm);
2583
	int r;
2584
	gpa_t gpa = ghc->gpa + offset;
2585

2586
	BUG_ON(len + offset > ghc->len);
2587

2588 2589 2590 2591
	if (slots->generation != ghc->generation) {
		if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
			return -EFAULT;
	}
2592

2593 2594 2595
	if (kvm_is_error_hva(ghc->hva))
		return -EFAULT;

2596
	if (unlikely(!ghc->memslot))
2597
		return kvm_read_guest(kvm, gpa, data, len);
2598

2599
	r = __copy_from_user(data, (void __user *)ghc->hva + offset, len);
2600 2601 2602 2603 2604
	if (r)
		return -EFAULT;

	return 0;
}
2605 2606 2607 2608 2609 2610 2611
EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached);

int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
			  void *data, unsigned long len)
{
	return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len);
}
2612
EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
2613

2614 2615
int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
{
2616 2617 2618
	const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));

	return kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
2619 2620 2621 2622 2623 2624 2625 2626 2627 2628
}
EXPORT_SYMBOL_GPL(kvm_clear_guest_page);

int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
{
	gfn_t gfn = gpa >> PAGE_SHIFT;
	int seg;
	int offset = offset_in_page(gpa);
	int ret;

2629
	while ((seg = next_segment(len, offset)) != 0) {
2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640
		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
		if (ret < 0)
			return ret;
		offset = 0;
		len -= seg;
		++gfn;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(kvm_clear_guest);

2641
static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot,
2642
				    gfn_t gfn)
A
Avi Kivity 已提交
2643
{
R
Rusty Russell 已提交
2644 2645
	if (memslot && memslot->dirty_bitmap) {
		unsigned long rel_gfn = gfn - memslot->base_gfn;
A
Avi Kivity 已提交
2646

2647
		set_bit_le(rel_gfn, memslot->dirty_bitmap);
A
Avi Kivity 已提交
2648 2649 2650
	}
}

2651 2652 2653 2654 2655
void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
{
	struct kvm_memory_slot *memslot;

	memslot = gfn_to_memslot(kvm, gfn);
2656
	mark_page_dirty_in_slot(memslot, gfn);
2657
}
2658
EXPORT_SYMBOL_GPL(mark_page_dirty);
2659

2660 2661 2662 2663 2664 2665 2666 2667 2668
void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
{
	struct kvm_memory_slot *memslot;

	memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
	mark_page_dirty_in_slot(memslot, gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);

2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691
void kvm_sigset_activate(struct kvm_vcpu *vcpu)
{
	if (!vcpu->sigset_active)
		return;

	/*
	 * This does a lockless modification of ->real_blocked, which is fine
	 * because, only current can change ->real_blocked and all readers of
	 * ->real_blocked don't care as long ->real_blocked is always a subset
	 * of ->blocked.
	 */
	sigprocmask(SIG_SETMASK, &vcpu->sigset, &current->real_blocked);
}

void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
{
	if (!vcpu->sigset_active)
		return;

	sigprocmask(SIG_SETMASK, &current->real_blocked, NULL);
	sigemptyset(&current->real_blocked);
}

W
Wanpeng Li 已提交
2692 2693
static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
{
2694
	unsigned int old, val, grow, grow_start;
W
Wanpeng Li 已提交
2695

2696
	old = val = vcpu->halt_poll_ns;
2697
	grow_start = READ_ONCE(halt_poll_ns_grow_start);
2698
	grow = READ_ONCE(halt_poll_ns_grow);
2699 2700 2701
	if (!grow)
		goto out;

2702 2703 2704
	val *= grow;
	if (val < grow_start)
		val = grow_start;
W
Wanpeng Li 已提交
2705

2706 2707 2708
	if (val > halt_poll_ns)
		val = halt_poll_ns;

W
Wanpeng Li 已提交
2709
	vcpu->halt_poll_ns = val;
2710
out:
2711
	trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
W
Wanpeng Li 已提交
2712 2713 2714 2715
}

static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
{
2716
	unsigned int old, val, shrink;
W
Wanpeng Li 已提交
2717

2718
	old = val = vcpu->halt_poll_ns;
2719 2720
	shrink = READ_ONCE(halt_poll_ns_shrink);
	if (shrink == 0)
W
Wanpeng Li 已提交
2721 2722
		val = 0;
	else
2723
		val /= shrink;
W
Wanpeng Li 已提交
2724 2725

	vcpu->halt_poll_ns = val;
2726
	trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
W
Wanpeng Li 已提交
2727 2728
}

2729 2730
static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
{
2731 2732 2733
	int ret = -EINTR;
	int idx = srcu_read_lock(&vcpu->kvm->srcu);

2734 2735
	if (kvm_arch_vcpu_runnable(vcpu)) {
		kvm_make_request(KVM_REQ_UNHALT, vcpu);
2736
		goto out;
2737 2738
	}
	if (kvm_cpu_has_pending_timer(vcpu))
2739
		goto out;
2740
	if (signal_pending(current))
2741
		goto out;
2742

2743 2744 2745 2746
	ret = 0;
out:
	srcu_read_unlock(&vcpu->kvm->srcu, idx);
	return ret;
2747 2748
}

2749 2750 2751 2752 2753 2754 2755 2756 2757
static inline void
update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited)
{
	if (waited)
		vcpu->stat.halt_poll_fail_ns += poll_ns;
	else
		vcpu->stat.halt_poll_success_ns += poll_ns;
}

E
Eddie Dong 已提交
2758 2759 2760
/*
 * The vCPU has executed a HLT instruction with in-kernel mode enabled.
 */
2761
void kvm_vcpu_block(struct kvm_vcpu *vcpu)
2762
{
2763
	ktime_t start, cur, poll_end;
2764
	bool waited = false;
W
Wanpeng Li 已提交
2765
	u64 block_ns;
2766

2767 2768
	kvm_arch_vcpu_blocking(vcpu);

2769
	start = cur = poll_end = ktime_get();
2770
	if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) {
W
Wanpeng Li 已提交
2771
		ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
2772

2773
		++vcpu->stat.halt_attempted_poll;
2774 2775 2776 2777 2778 2779 2780
		do {
			/*
			 * This sets KVM_REQ_UNHALT if an interrupt
			 * arrives.
			 */
			if (kvm_vcpu_check_block(vcpu) < 0) {
				++vcpu->stat.halt_successful_poll;
2781 2782
				if (!vcpu_valid_wakeup(vcpu))
					++vcpu->stat.halt_poll_invalid;
2783 2784
				goto out;
			}
2785
			poll_end = cur = ktime_get();
2786 2787
		} while (single_task_running() && ktime_before(cur, stop));
	}
2788

2789
	prepare_to_rcuwait(&vcpu->wait);
2790
	for (;;) {
2791
		set_current_state(TASK_INTERRUPTIBLE);
2792

2793
		if (kvm_vcpu_check_block(vcpu) < 0)
2794 2795
			break;

2796
		waited = true;
E
Eddie Dong 已提交
2797 2798
		schedule();
	}
2799
	finish_rcuwait(&vcpu->wait);
2800 2801
	cur = ktime_get();
out:
2802
	kvm_arch_vcpu_unblocking(vcpu);
W
Wanpeng Li 已提交
2803 2804
	block_ns = ktime_to_ns(cur) - ktime_to_ns(start);

2805 2806 2807
	update_halt_poll_stats(
		vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited);

2808 2809
	if (!kvm_arch_no_poll(vcpu)) {
		if (!vcpu_valid_wakeup(vcpu)) {
W
Wanpeng Li 已提交
2810
			shrink_halt_poll_ns(vcpu);
2811
		} else if (vcpu->kvm->max_halt_poll_ns) {
2812 2813 2814
			if (block_ns <= vcpu->halt_poll_ns)
				;
			/* we had a long block, shrink polling */
2815 2816
			else if (vcpu->halt_poll_ns &&
					block_ns > vcpu->kvm->max_halt_poll_ns)
2817 2818
				shrink_halt_poll_ns(vcpu);
			/* we had a short halt and our poll time is too small */
2819 2820
			else if (vcpu->halt_poll_ns < vcpu->kvm->max_halt_poll_ns &&
					block_ns < vcpu->kvm->max_halt_poll_ns)
2821 2822 2823 2824 2825
				grow_halt_poll_ns(vcpu);
		} else {
			vcpu->halt_poll_ns = 0;
		}
	}
W
Wanpeng Li 已提交
2826

2827 2828
	trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
	kvm_arch_vcpu_block_finish(vcpu);
E
Eddie Dong 已提交
2829
}
2830
EXPORT_SYMBOL_GPL(kvm_vcpu_block);
E
Eddie Dong 已提交
2831

2832
bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
2833
{
2834
	struct rcuwait *waitp;
2835

2836 2837
	waitp = kvm_arch_vcpu_get_wait(vcpu);
	if (rcuwait_wake_up(waitp)) {
2838
		WRITE_ONCE(vcpu->ready, true);
2839
		++vcpu->stat.halt_wakeup;
2840
		return true;
2841 2842
	}

2843
	return false;
2844 2845 2846
}
EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up);

2847
#ifndef CONFIG_S390
2848 2849 2850 2851 2852 2853 2854 2855
/*
 * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
 */
void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
{
	int me;
	int cpu = vcpu->cpu;

2856 2857 2858
	if (kvm_vcpu_wake_up(vcpu))
		return;

2859 2860 2861 2862 2863 2864
	me = get_cpu();
	if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
		if (kvm_arch_vcpu_should_kick(vcpu))
			smp_send_reschedule(cpu);
	put_cpu();
}
2865
EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
2866
#endif /* !CONFIG_S390 */
2867

2868
int kvm_vcpu_yield_to(struct kvm_vcpu *target)
2869 2870 2871
{
	struct pid *pid;
	struct task_struct *task = NULL;
2872
	int ret = 0;
2873 2874 2875 2876

	rcu_read_lock();
	pid = rcu_dereference(target->pid);
	if (pid)
2877
		task = get_pid_task(pid, PIDTYPE_PID);
2878 2879
	rcu_read_unlock();
	if (!task)
2880 2881
		return ret;
	ret = yield_to(task, 1);
2882
	put_task_struct(task);
2883 2884

	return ret;
2885 2886 2887
}
EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);

2888 2889 2890 2891 2892 2893
/*
 * Helper that checks whether a VCPU is eligible for directed yield.
 * Most eligible candidate to yield is decided by following heuristics:
 *
 *  (a) VCPU which has not done pl-exit or cpu relax intercepted recently
 *  (preempted lock holder), indicated by @in_spin_loop.
F
Fuad Tabba 已提交
2894
 *  Set at the beginning and cleared at the end of interception/PLE handler.
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909
 *
 *  (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
 *  chance last time (mostly it has become eligible now since we have probably
 *  yielded to lockholder in last iteration. This is done by toggling
 *  @dy_eligible each time a VCPU checked for eligibility.)
 *
 *  Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
 *  to preempted lock-holder could result in wrong VCPU selection and CPU
 *  burning. Giving priority for a potential lock-holder increases lock
 *  progress.
 *
 *  Since algorithm is based on heuristics, accessing another VCPU data without
 *  locking does not harm. It may result in trying to yield to  same VCPU, fail
 *  and continue with next VCPU and so on.
 */
2910
static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
2911
{
2912
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
2913 2914 2915
	bool eligible;

	eligible = !vcpu->spin_loop.in_spin_loop ||
2916
		    vcpu->spin_loop.dy_eligible;
2917 2918 2919 2920 2921

	if (vcpu->spin_loop.in_spin_loop)
		kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);

	return eligible;
2922 2923
#else
	return true;
2924
#endif
2925
}
2926

2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
/*
 * Unlike kvm_arch_vcpu_runnable, this function is called outside
 * a vcpu_load/vcpu_put pair.  However, for most architectures
 * kvm_arch_vcpu_runnable does not require vcpu_load.
 */
bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu)
{
	return kvm_arch_vcpu_runnable(vcpu);
}

static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu)
{
	if (kvm_arch_dy_runnable(vcpu))
		return true;

#ifdef CONFIG_KVM_ASYNC_PF
	if (!list_empty_careful(&vcpu->async_pf.done))
		return true;
#endif

	return false;
}

2950
void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
Z
Zhai, Edwin 已提交
2951
{
2952 2953 2954 2955
	struct kvm *kvm = me->kvm;
	struct kvm_vcpu *vcpu;
	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
	int yielded = 0;
2956
	int try = 3;
2957 2958
	int pass;
	int i;
Z
Zhai, Edwin 已提交
2959

2960
	kvm_vcpu_set_in_spin_loop(me, true);
2961 2962 2963 2964 2965 2966 2967
	/*
	 * We boost the priority of a VCPU that is runnable but not
	 * currently running, because it got preempted by something
	 * else and called schedule in __vcpu_run.  Hopefully that
	 * VCPU is holding the lock that we need and will release it.
	 * We approximate round-robin by starting at the last boosted VCPU.
	 */
2968
	for (pass = 0; pass < 2 && !yielded && try; pass++) {
2969
		kvm_for_each_vcpu(i, vcpu, kvm) {
2970
			if (!pass && i <= last_boosted_vcpu) {
2971 2972 2973 2974
				i = last_boosted_vcpu;
				continue;
			} else if (pass && i > last_boosted_vcpu)
				break;
2975
			if (!READ_ONCE(vcpu->ready))
2976
				continue;
2977 2978
			if (vcpu == me)
				continue;
2979 2980
			if (rcuwait_active(&vcpu->wait) &&
			    !vcpu_dy_runnable(vcpu))
2981
				continue;
2982 2983
			if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode &&
				!kvm_arch_vcpu_in_kernel(vcpu))
2984
				continue;
2985 2986
			if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
				continue;
2987 2988 2989

			yielded = kvm_vcpu_yield_to(vcpu);
			if (yielded > 0) {
2990 2991
				kvm->last_boosted_vcpu = i;
				break;
2992 2993 2994 2995
			} else if (yielded < 0) {
				try--;
				if (!try)
					break;
2996 2997 2998
			}
		}
	}
2999
	kvm_vcpu_set_in_spin_loop(me, false);
3000 3001 3002

	/* Ensure vcpu is not eligible during next spinloop */
	kvm_vcpu_set_dy_eligible(me, false);
Z
Zhai, Edwin 已提交
3003 3004 3005
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);

3006
static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
3007
{
3008
	struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data;
3009 3010
	struct page *page;

3011
	if (vmf->pgoff == 0)
3012
		page = virt_to_page(vcpu->run);
A
Avi Kivity 已提交
3013
#ifdef CONFIG_X86
3014
	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
3015
		page = virt_to_page(vcpu->arch.pio_data);
3016
#endif
3017
#ifdef CONFIG_KVM_MMIO
3018 3019
	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
A
Avi Kivity 已提交
3020
#endif
3021
	else
3022
		return kvm_arch_vcpu_fault(vcpu, vmf);
3023
	get_page(page);
3024 3025
	vmf->page = page;
	return 0;
3026 3027
}

3028
static const struct vm_operations_struct kvm_vcpu_vm_ops = {
3029
	.fault = kvm_vcpu_fault,
3030 3031 3032 3033 3034 3035 3036 3037
};

static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
{
	vma->vm_ops = &kvm_vcpu_vm_ops;
	return 0;
}

A
Avi Kivity 已提交
3038 3039 3040 3041
static int kvm_vcpu_release(struct inode *inode, struct file *filp)
{
	struct kvm_vcpu *vcpu = filp->private_data;

A
Al Viro 已提交
3042
	kvm_put_kvm(vcpu->kvm);
A
Avi Kivity 已提交
3043 3044 3045
	return 0;
}

3046
static struct file_operations kvm_vcpu_fops = {
A
Avi Kivity 已提交
3047 3048
	.release        = kvm_vcpu_release,
	.unlocked_ioctl = kvm_vcpu_ioctl,
3049
	.mmap           = kvm_vcpu_mmap,
3050
	.llseek		= noop_llseek,
3051
	KVM_COMPAT(kvm_vcpu_compat_ioctl),
A
Avi Kivity 已提交
3052 3053 3054 3055 3056 3057 3058
};

/*
 * Allocates an inode for the vcpu.
 */
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
3059 3060 3061 3062
	char name[8 + 1 + ITOA_MAX_LEN + 1];

	snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id);
	return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
A
Avi Kivity 已提交
3063 3064
}

3065
static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
3066
{
3067
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
3068
	struct dentry *debugfs_dentry;
3069 3070 3071
	char dir_name[ITOA_MAX_LEN * 2];

	if (!debugfs_initialized())
3072
		return;
3073 3074

	snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
3075 3076
	debugfs_dentry = debugfs_create_dir(dir_name,
					    vcpu->kvm->debugfs_dentry);
3077

3078
	kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry);
3079
#endif
3080 3081
}

3082 3083 3084
/*
 * Creates some virtual cpus.  Good luck creating more than one.
 */
3085
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
3086 3087
{
	int r;
3088
	struct kvm_vcpu *vcpu;
3089
	struct page *page;
3090

G
Greg Kurz 已提交
3091
	if (id >= KVM_MAX_VCPU_ID)
3092 3093
		return -EINVAL;

3094 3095 3096 3097 3098 3099 3100 3101 3102
	mutex_lock(&kvm->lock);
	if (kvm->created_vcpus == KVM_MAX_VCPUS) {
		mutex_unlock(&kvm->lock);
		return -EINVAL;
	}

	kvm->created_vcpus++;
	mutex_unlock(&kvm->lock);

3103 3104 3105 3106
	r = kvm_arch_vcpu_precreate(kvm, id);
	if (r)
		goto vcpu_decrement;

3107 3108 3109
	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
	if (!vcpu) {
		r = -ENOMEM;
3110 3111
		goto vcpu_decrement;
	}
3112

3113
	BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE);
3114 3115 3116
	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
	if (!page) {
		r = -ENOMEM;
3117
		goto vcpu_free;
3118 3119 3120 3121
	}
	vcpu->run = page_address(page);

	kvm_vcpu_init(vcpu, kvm, id);
3122 3123 3124

	r = kvm_arch_vcpu_create(vcpu);
	if (r)
3125
		goto vcpu_free_run_page;
3126

S
Shaohua Li 已提交
3127
	mutex_lock(&kvm->lock);
3128 3129 3130 3131
	if (kvm_get_vcpu_by_id(kvm, id)) {
		r = -EEXIST;
		goto unlock_vcpu_destroy;
	}
3132

3133 3134
	vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
	BUG_ON(kvm->vcpus[vcpu->vcpu_idx]);
3135

R
Rusty Russell 已提交
3136
	/* Now it's all set up, let userspace reach it */
A
Al Viro 已提交
3137
	kvm_get_kvm(kvm);
A
Avi Kivity 已提交
3138
	r = create_vcpu_fd(vcpu);
3139
	if (r < 0) {
3140
		kvm_put_kvm_no_destroy(kvm);
3141
		goto unlock_vcpu_destroy;
3142 3143
	}

3144
	kvm->vcpus[vcpu->vcpu_idx] = vcpu;
3145 3146 3147 3148 3149

	/*
	 * Pairs with smp_rmb() in kvm_get_vcpu.  Write kvm->vcpus
	 * before kvm->online_vcpu's incremented value.
	 */
3150 3151 3152 3153
	smp_wmb();
	atomic_inc(&kvm->online_vcpus);

	mutex_unlock(&kvm->lock);
3154
	kvm_arch_vcpu_postcreate(vcpu);
3155
	kvm_create_vcpu_debugfs(vcpu);
R
Rusty Russell 已提交
3156
	return r;
3157

3158
unlock_vcpu_destroy:
3159
	mutex_unlock(&kvm->lock);
3160
	kvm_arch_vcpu_destroy(vcpu);
3161 3162
vcpu_free_run_page:
	free_page((unsigned long)vcpu->run);
3163 3164
vcpu_free:
	kmem_cache_free(kvm_vcpu_cache, vcpu);
3165 3166 3167 3168
vcpu_decrement:
	mutex_lock(&kvm->lock);
	kvm->created_vcpus--;
	mutex_unlock(&kvm->lock);
3169 3170 3171
	return r;
}

A
Avi Kivity 已提交
3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182
static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
{
	if (sigset) {
		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
		vcpu->sigset_active = 1;
		vcpu->sigset = *sigset;
	} else
		vcpu->sigset_active = 0;
	return 0;
}

A
Avi Kivity 已提交
3183 3184
static long kvm_vcpu_ioctl(struct file *filp,
			   unsigned int ioctl, unsigned long arg)
A
Avi Kivity 已提交
3185
{
A
Avi Kivity 已提交
3186
	struct kvm_vcpu *vcpu = filp->private_data;
A
Al Viro 已提交
3187
	void __user *argp = (void __user *)arg;
3188
	int r;
3189 3190
	struct kvm_fpu *fpu = NULL;
	struct kvm_sregs *kvm_sregs = NULL;
A
Avi Kivity 已提交
3191

3192 3193
	if (vcpu->kvm->mm != current->mm)
		return -EIO;
3194

3195 3196 3197
	if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
		return -EINVAL;

3198
	/*
3199 3200
	 * Some architectures have vcpu ioctls that are asynchronous to vcpu
	 * execution; mutex_lock() would break them.
3201
	 */
3202 3203
	r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
	if (r != -ENOIOCTLCMD)
3204
		return r;
3205

3206 3207
	if (mutex_lock_killable(&vcpu->mutex))
		return -EINTR;
A
Avi Kivity 已提交
3208
	switch (ioctl) {
3209 3210
	case KVM_RUN: {
		struct pid *oldpid;
3211 3212 3213
		r = -EINVAL;
		if (arg)
			goto out;
3214
		oldpid = rcu_access_pointer(vcpu->pid);
3215
		if (unlikely(oldpid != task_pid(current))) {
3216
			/* The thread running this VCPU changed. */
3217
			struct pid *newpid;
3218

3219 3220 3221 3222 3223
			r = kvm_arch_vcpu_run_pid_change(vcpu);
			if (r)
				break;

			newpid = get_task_pid(current, PIDTYPE_PID);
3224 3225 3226 3227 3228
			rcu_assign_pointer(vcpu->pid, newpid);
			if (oldpid)
				synchronize_rcu();
			put_pid(oldpid);
		}
3229
		r = kvm_arch_vcpu_ioctl_run(vcpu);
3230
		trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
A
Avi Kivity 已提交
3231
		break;
3232
	}
A
Avi Kivity 已提交
3233
	case KVM_GET_REGS: {
3234
		struct kvm_regs *kvm_regs;
A
Avi Kivity 已提交
3235

3236
		r = -ENOMEM;
3237
		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL_ACCOUNT);
3238
		if (!kvm_regs)
A
Avi Kivity 已提交
3239
			goto out;
3240 3241 3242
		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
		if (r)
			goto out_free1;
A
Avi Kivity 已提交
3243
		r = -EFAULT;
3244 3245
		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
			goto out_free1;
A
Avi Kivity 已提交
3246
		r = 0;
3247 3248
out_free1:
		kfree(kvm_regs);
A
Avi Kivity 已提交
3249 3250 3251
		break;
	}
	case KVM_SET_REGS: {
3252
		struct kvm_regs *kvm_regs;
A
Avi Kivity 已提交
3253

3254 3255 3256
		kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
		if (IS_ERR(kvm_regs)) {
			r = PTR_ERR(kvm_regs);
A
Avi Kivity 已提交
3257
			goto out;
3258
		}
3259 3260
		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
		kfree(kvm_regs);
A
Avi Kivity 已提交
3261 3262 3263
		break;
	}
	case KVM_GET_SREGS: {
3264 3265
		kvm_sregs = kzalloc(sizeof(struct kvm_sregs),
				    GFP_KERNEL_ACCOUNT);
3266 3267 3268 3269
		r = -ENOMEM;
		if (!kvm_sregs)
			goto out;
		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
A
Avi Kivity 已提交
3270 3271 3272
		if (r)
			goto out;
		r = -EFAULT;
3273
		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
A
Avi Kivity 已提交
3274 3275 3276 3277 3278
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_SREGS: {
3279 3280 3281
		kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
		if (IS_ERR(kvm_sregs)) {
			r = PTR_ERR(kvm_sregs);
G
Guo Chao 已提交
3282
			kvm_sregs = NULL;
A
Avi Kivity 已提交
3283
			goto out;
3284
		}
3285
		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
A
Avi Kivity 已提交
3286 3287
		break;
	}
3288 3289 3290 3291 3292 3293 3294
	case KVM_GET_MP_STATE: {
		struct kvm_mp_state mp_state;

		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
		if (r)
			goto out;
		r = -EFAULT;
3295
		if (copy_to_user(argp, &mp_state, sizeof(mp_state)))
3296 3297 3298 3299 3300 3301 3302 3303
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_MP_STATE: {
		struct kvm_mp_state mp_state;

		r = -EFAULT;
3304
		if (copy_from_user(&mp_state, argp, sizeof(mp_state)))
3305 3306 3307 3308
			goto out;
		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
		break;
	}
A
Avi Kivity 已提交
3309 3310 3311 3312
	case KVM_TRANSLATE: {
		struct kvm_translation tr;

		r = -EFAULT;
3313
		if (copy_from_user(&tr, argp, sizeof(tr)))
A
Avi Kivity 已提交
3314
			goto out;
3315
		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
A
Avi Kivity 已提交
3316 3317 3318
		if (r)
			goto out;
		r = -EFAULT;
3319
		if (copy_to_user(argp, &tr, sizeof(tr)))
A
Avi Kivity 已提交
3320 3321 3322 3323
			goto out;
		r = 0;
		break;
	}
J
Jan Kiszka 已提交
3324 3325
	case KVM_SET_GUEST_DEBUG: {
		struct kvm_guest_debug dbg;
A
Avi Kivity 已提交
3326 3327

		r = -EFAULT;
3328
		if (copy_from_user(&dbg, argp, sizeof(dbg)))
A
Avi Kivity 已提交
3329
			goto out;
J
Jan Kiszka 已提交
3330
		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
A
Avi Kivity 已提交
3331 3332
		break;
	}
A
Avi Kivity 已提交
3333 3334 3335 3336 3337 3338 3339 3340 3341
	case KVM_SET_SIGNAL_MASK: {
		struct kvm_signal_mask __user *sigmask_arg = argp;
		struct kvm_signal_mask kvm_sigmask;
		sigset_t sigset, *p;

		p = NULL;
		if (argp) {
			r = -EFAULT;
			if (copy_from_user(&kvm_sigmask, argp,
3342
					   sizeof(kvm_sigmask)))
A
Avi Kivity 已提交
3343 3344
				goto out;
			r = -EINVAL;
3345
			if (kvm_sigmask.len != sizeof(sigset))
A
Avi Kivity 已提交
3346 3347 3348
				goto out;
			r = -EFAULT;
			if (copy_from_user(&sigset, sigmask_arg->sigset,
3349
					   sizeof(sigset)))
A
Avi Kivity 已提交
3350 3351 3352
				goto out;
			p = &sigset;
		}
3353
		r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
A
Avi Kivity 已提交
3354 3355
		break;
	}
A
Avi Kivity 已提交
3356
	case KVM_GET_FPU: {
3357
		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL_ACCOUNT);
3358 3359 3360 3361
		r = -ENOMEM;
		if (!fpu)
			goto out;
		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
A
Avi Kivity 已提交
3362 3363 3364
		if (r)
			goto out;
		r = -EFAULT;
3365
		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
A
Avi Kivity 已提交
3366 3367 3368 3369 3370
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_FPU: {
3371 3372 3373
		fpu = memdup_user(argp, sizeof(*fpu));
		if (IS_ERR(fpu)) {
			r = PTR_ERR(fpu);
G
Guo Chao 已提交
3374
			fpu = NULL;
A
Avi Kivity 已提交
3375
			goto out;
3376
		}
3377
		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
A
Avi Kivity 已提交
3378 3379
		break;
	}
A
Avi Kivity 已提交
3380
	default:
3381
		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
A
Avi Kivity 已提交
3382 3383
	}
out:
3384
	mutex_unlock(&vcpu->mutex);
3385 3386
	kfree(fpu);
	kfree(kvm_sregs);
A
Avi Kivity 已提交
3387 3388 3389
	return r;
}

3390
#ifdef CONFIG_KVM_COMPAT
3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409
static long kvm_vcpu_compat_ioctl(struct file *filp,
				  unsigned int ioctl, unsigned long arg)
{
	struct kvm_vcpu *vcpu = filp->private_data;
	void __user *argp = compat_ptr(arg);
	int r;

	if (vcpu->kvm->mm != current->mm)
		return -EIO;

	switch (ioctl) {
	case KVM_SET_SIGNAL_MASK: {
		struct kvm_signal_mask __user *sigmask_arg = argp;
		struct kvm_signal_mask kvm_sigmask;
		sigset_t sigset;

		if (argp) {
			r = -EFAULT;
			if (copy_from_user(&kvm_sigmask, argp,
3410
					   sizeof(kvm_sigmask)))
3411 3412
				goto out;
			r = -EINVAL;
A
Al Viro 已提交
3413
			if (kvm_sigmask.len != sizeof(compat_sigset_t))
3414 3415
				goto out;
			r = -EFAULT;
3416 3417
			if (get_compat_sigset(&sigset,
					      (compat_sigset_t __user *)sigmask_arg->sigset))
3418
				goto out;
3419 3420 3421
			r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
		} else
			r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432
		break;
	}
	default:
		r = kvm_vcpu_ioctl(filp, ioctl, arg);
	}

out:
	return r;
}
#endif

3433 3434 3435 3436 3437 3438 3439 3440 3441 3442
static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma)
{
	struct kvm_device *dev = filp->private_data;

	if (dev->ops->mmap)
		return dev->ops->mmap(dev, vma);

	return -ENODEV;
}

S
Scott Wood 已提交
3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463
static int kvm_device_ioctl_attr(struct kvm_device *dev,
				 int (*accessor)(struct kvm_device *dev,
						 struct kvm_device_attr *attr),
				 unsigned long arg)
{
	struct kvm_device_attr attr;

	if (!accessor)
		return -EPERM;

	if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
		return -EFAULT;

	return accessor(dev, &attr);
}

static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
			     unsigned long arg)
{
	struct kvm_device *dev = filp->private_data;

3464 3465 3466
	if (dev->kvm->mm != current->mm)
		return -EIO;

S
Scott Wood 已提交
3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486
	switch (ioctl) {
	case KVM_SET_DEVICE_ATTR:
		return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg);
	case KVM_GET_DEVICE_ATTR:
		return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg);
	case KVM_HAS_DEVICE_ATTR:
		return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg);
	default:
		if (dev->ops->ioctl)
			return dev->ops->ioctl(dev, ioctl, arg);

		return -ENOTTY;
	}
}

static int kvm_device_release(struct inode *inode, struct file *filp)
{
	struct kvm_device *dev = filp->private_data;
	struct kvm *kvm = dev->kvm;

3487 3488 3489 3490 3491 3492 3493
	if (dev->ops->release) {
		mutex_lock(&kvm->lock);
		list_del(&dev->vm_node);
		dev->ops->release(dev);
		mutex_unlock(&kvm->lock);
	}

S
Scott Wood 已提交
3494 3495 3496 3497 3498 3499 3500
	kvm_put_kvm(kvm);
	return 0;
}

static const struct file_operations kvm_device_fops = {
	.unlocked_ioctl = kvm_device_ioctl,
	.release = kvm_device_release,
3501
	KVM_COMPAT(kvm_device_ioctl),
3502
	.mmap = kvm_device_mmap,
S
Scott Wood 已提交
3503 3504 3505 3506 3507 3508 3509 3510 3511 3512
};

struct kvm_device *kvm_device_from_filp(struct file *filp)
{
	if (filp->f_op != &kvm_device_fops)
		return NULL;

	return filp->private_data;
}

3513
static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
3514
#ifdef CONFIG_KVM_MPIC
3515 3516
	[KVM_DEV_TYPE_FSL_MPIC_20]	= &kvm_mpic_ops,
	[KVM_DEV_TYPE_FSL_MPIC_42]	= &kvm_mpic_ops,
3517
#endif
3518 3519
};

3520
int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type)
3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531
{
	if (type >= ARRAY_SIZE(kvm_device_ops_table))
		return -ENOSPC;

	if (kvm_device_ops_table[type] != NULL)
		return -EEXIST;

	kvm_device_ops_table[type] = ops;
	return 0;
}

3532 3533 3534 3535 3536 3537
void kvm_unregister_device_ops(u32 type)
{
	if (kvm_device_ops_table[type] != NULL)
		kvm_device_ops_table[type] = NULL;
}

S
Scott Wood 已提交
3538 3539 3540
static int kvm_ioctl_create_device(struct kvm *kvm,
				   struct kvm_create_device *cd)
{
3541
	const struct kvm_device_ops *ops = NULL;
S
Scott Wood 已提交
3542 3543
	struct kvm_device *dev;
	bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
P
Paolo Bonzini 已提交
3544
	int type;
S
Scott Wood 已提交
3545 3546
	int ret;

3547 3548 3549
	if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
		return -ENODEV;

P
Paolo Bonzini 已提交
3550 3551
	type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table));
	ops = kvm_device_ops_table[type];
3552
	if (ops == NULL)
S
Scott Wood 已提交
3553 3554 3555 3556 3557
		return -ENODEV;

	if (test)
		return 0;

3558
	dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT);
S
Scott Wood 已提交
3559 3560 3561 3562 3563 3564
	if (!dev)
		return -ENOMEM;

	dev->ops = ops;
	dev->kvm = kvm;

3565
	mutex_lock(&kvm->lock);
P
Paolo Bonzini 已提交
3566
	ret = ops->create(dev, type);
S
Scott Wood 已提交
3567
	if (ret < 0) {
3568
		mutex_unlock(&kvm->lock);
S
Scott Wood 已提交
3569 3570 3571
		kfree(dev);
		return ret;
	}
3572 3573
	list_add(&dev->vm_node, &kvm->devices);
	mutex_unlock(&kvm->lock);
S
Scott Wood 已提交
3574

3575 3576 3577
	if (ops->init)
		ops->init(dev);

3578
	kvm_get_kvm(kvm);
3579
	ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
S
Scott Wood 已提交
3580
	if (ret < 0) {
3581
		kvm_put_kvm_no_destroy(kvm);
3582 3583 3584
		mutex_lock(&kvm->lock);
		list_del(&dev->vm_node);
		mutex_unlock(&kvm->lock);
3585
		ops->destroy(dev);
S
Scott Wood 已提交
3586 3587 3588 3589 3590 3591 3592
		return ret;
	}

	cd->fd = ret;
	return 0;
}

3593 3594 3595 3596 3597 3598 3599 3600 3601 3602
static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
{
	switch (arg) {
	case KVM_CAP_USER_MEMORY:
	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
	case KVM_CAP_INTERNAL_ERROR_DATA:
#ifdef CONFIG_HAVE_KVM_MSI
	case KVM_CAP_SIGNAL_MSI:
#endif
3603
#ifdef CONFIG_HAVE_KVM_IRQFD
3604
	case KVM_CAP_IRQFD:
3605 3606
	case KVM_CAP_IRQFD_RESAMPLE:
#endif
3607
	case KVM_CAP_IOEVENTFD_ANY_LENGTH:
3608
	case KVM_CAP_CHECK_EXTENSION_VM:
3609
	case KVM_CAP_ENABLE_CAP_VM:
3610
	case KVM_CAP_HALT_POLL:
3611
		return 1;
3612
#ifdef CONFIG_KVM_MMIO
3613 3614
	case KVM_CAP_COALESCED_MMIO:
		return KVM_COALESCED_MMIO_PAGE_OFFSET;
P
Peng Hao 已提交
3615 3616
	case KVM_CAP_COALESCED_PIO:
		return 1;
3617
#endif
3618 3619 3620 3621
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2:
		return KVM_DIRTY_LOG_MANUAL_CAPS;
#endif
3622 3623 3624
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
	case KVM_CAP_IRQ_ROUTING:
		return KVM_MAX_IRQ_ROUTES;
3625 3626 3627 3628
#endif
#if KVM_ADDRESS_SPACE_NUM > 1
	case KVM_CAP_MULTI_ADDRESS_SPACE:
		return KVM_ADDRESS_SPACE_NUM;
3629
#endif
3630 3631
	case KVM_CAP_NR_MEMSLOTS:
		return KVM_USER_MEM_SLOTS;
3632 3633 3634 3635 3636 3637
	default:
		break;
	}
	return kvm_vm_ioctl_check_extension(kvm, arg);
}

3638 3639 3640 3641 3642 3643 3644 3645 3646 3647
int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
						  struct kvm_enable_cap *cap)
{
	return -EINVAL;
}

static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
					   struct kvm_enable_cap *cap)
{
	switch (cap->cap) {
3648
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
3649 3650 3651 3652 3653 3654 3655
	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: {
		u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE;

		if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE)
			allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS;

		if (cap->flags || (cap->args[0] & ~allowed_options))
3656 3657 3658
			return -EINVAL;
		kvm->manual_dirty_log_protect = cap->args[0];
		return 0;
3659
	}
3660
#endif
3661 3662 3663 3664 3665 3666 3667
	case KVM_CAP_HALT_POLL: {
		if (cap->flags || cap->args[0] != (unsigned int)cap->args[0])
			return -EINVAL;

		kvm->max_halt_poll_ns = cap->args[0];
		return 0;
	}
3668 3669 3670 3671 3672
	default:
		return kvm_vm_ioctl_enable_cap(kvm, cap);
	}
}

A
Avi Kivity 已提交
3673 3674 3675 3676 3677
static long kvm_vm_ioctl(struct file *filp,
			   unsigned int ioctl, unsigned long arg)
{
	struct kvm *kvm = filp->private_data;
	void __user *argp = (void __user *)arg;
3678
	int r;
A
Avi Kivity 已提交
3679

3680 3681
	if (kvm->mm != current->mm)
		return -EIO;
A
Avi Kivity 已提交
3682 3683 3684 3685
	switch (ioctl) {
	case KVM_CREATE_VCPU:
		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
		break;
3686 3687 3688 3689 3690 3691 3692 3693 3694
	case KVM_ENABLE_CAP: {
		struct kvm_enable_cap cap;

		r = -EFAULT;
		if (copy_from_user(&cap, argp, sizeof(cap)))
			goto out;
		r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap);
		break;
	}
3695 3696 3697 3698 3699
	case KVM_SET_USER_MEMORY_REGION: {
		struct kvm_userspace_memory_region kvm_userspace_mem;

		r = -EFAULT;
		if (copy_from_user(&kvm_userspace_mem, argp,
3700
						sizeof(kvm_userspace_mem)))
3701 3702
			goto out;

3703
		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
A
Avi Kivity 已提交
3704 3705 3706 3707 3708 3709
		break;
	}
	case KVM_GET_DIRTY_LOG: {
		struct kvm_dirty_log log;

		r = -EFAULT;
3710
		if (copy_from_user(&log, argp, sizeof(log)))
A
Avi Kivity 已提交
3711
			goto out;
3712
		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
A
Avi Kivity 已提交
3713 3714
		break;
	}
3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
	case KVM_CLEAR_DIRTY_LOG: {
		struct kvm_clear_dirty_log log;

		r = -EFAULT;
		if (copy_from_user(&log, argp, sizeof(log)))
			goto out;
		r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
		break;
	}
#endif
3726
#ifdef CONFIG_KVM_MMIO
3727 3728
	case KVM_REGISTER_COALESCED_MMIO: {
		struct kvm_coalesced_mmio_zone zone;
3729

3730
		r = -EFAULT;
3731
		if (copy_from_user(&zone, argp, sizeof(zone)))
3732 3733 3734 3735 3736 3737
			goto out;
		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
		break;
	}
	case KVM_UNREGISTER_COALESCED_MMIO: {
		struct kvm_coalesced_mmio_zone zone;
3738

3739
		r = -EFAULT;
3740
		if (copy_from_user(&zone, argp, sizeof(zone)))
3741 3742 3743 3744 3745
			goto out;
		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
		break;
	}
#endif
G
Gregory Haskins 已提交
3746 3747 3748 3749
	case KVM_IRQFD: {
		struct kvm_irqfd data;

		r = -EFAULT;
3750
		if (copy_from_user(&data, argp, sizeof(data)))
G
Gregory Haskins 已提交
3751
			goto out;
3752
		r = kvm_irqfd(kvm, &data);
G
Gregory Haskins 已提交
3753 3754
		break;
	}
G
Gregory Haskins 已提交
3755 3756 3757 3758
	case KVM_IOEVENTFD: {
		struct kvm_ioeventfd data;

		r = -EFAULT;
3759
		if (copy_from_user(&data, argp, sizeof(data)))
G
Gregory Haskins 已提交
3760 3761 3762 3763
			goto out;
		r = kvm_ioeventfd(kvm, &data);
		break;
	}
3764 3765 3766 3767 3768
#ifdef CONFIG_HAVE_KVM_MSI
	case KVM_SIGNAL_MSI: {
		struct kvm_msi msi;

		r = -EFAULT;
3769
		if (copy_from_user(&msi, argp, sizeof(msi)))
3770 3771 3772 3773
			goto out;
		r = kvm_send_userspace_msi(kvm, &msi);
		break;
	}
3774 3775 3776 3777 3778 3779 3780
#endif
#ifdef __KVM_HAVE_IRQ_LINE
	case KVM_IRQ_LINE_STATUS:
	case KVM_IRQ_LINE: {
		struct kvm_irq_level irq_event;

		r = -EFAULT;
3781
		if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
3782 3783
			goto out;

3784 3785
		r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
					ioctl == KVM_IRQ_LINE_STATUS);
3786 3787 3788 3789 3790
		if (r)
			goto out;

		r = -EFAULT;
		if (ioctl == KVM_IRQ_LINE_STATUS) {
3791
			if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
3792 3793 3794 3795 3796 3797
				goto out;
		}

		r = 0;
		break;
	}
3798
#endif
3799 3800 3801 3802
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
	case KVM_SET_GSI_ROUTING: {
		struct kvm_irq_routing routing;
		struct kvm_irq_routing __user *urouting;
3803
		struct kvm_irq_routing_entry *entries = NULL;
3804 3805 3806 3807 3808

		r = -EFAULT;
		if (copy_from_user(&routing, argp, sizeof(routing)))
			goto out;
		r = -EINVAL;
3809 3810
		if (!kvm_arch_can_set_irq_routing(kvm))
			goto out;
3811
		if (routing.nr > KVM_MAX_IRQ_ROUTES)
3812 3813 3814
			goto out;
		if (routing.flags)
			goto out;
3815 3816
		if (routing.nr) {
			urouting = argp;
D
Denis Efremov 已提交
3817 3818 3819 3820 3821 3822 3823
			entries = vmemdup_user(urouting->entries,
					       array_size(sizeof(*entries),
							  routing.nr));
			if (IS_ERR(entries)) {
				r = PTR_ERR(entries);
				goto out;
			}
3824
		}
3825 3826
		r = kvm_set_irq_routing(kvm, entries, routing.nr,
					routing.flags);
D
Denis Efremov 已提交
3827
		kvfree(entries);
3828 3829 3830
		break;
	}
#endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
S
Scott Wood 已提交
3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848
	case KVM_CREATE_DEVICE: {
		struct kvm_create_device cd;

		r = -EFAULT;
		if (copy_from_user(&cd, argp, sizeof(cd)))
			goto out;

		r = kvm_ioctl_create_device(kvm, &cd);
		if (r)
			goto out;

		r = -EFAULT;
		if (copy_to_user(argp, &cd, sizeof(cd)))
			goto out;

		r = 0;
		break;
	}
3849 3850 3851
	case KVM_CHECK_EXTENSION:
		r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
		break;
3852
	default:
3853
		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
3854 3855 3856 3857 3858
	}
out:
	return r;
}

3859
#ifdef CONFIG_KVM_COMPAT
3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883
struct compat_kvm_dirty_log {
	__u32 slot;
	__u32 padding1;
	union {
		compat_uptr_t dirty_bitmap; /* one bit per page */
		__u64 padding2;
	};
};

static long kvm_vm_compat_ioctl(struct file *filp,
			   unsigned int ioctl, unsigned long arg)
{
	struct kvm *kvm = filp->private_data;
	int r;

	if (kvm->mm != current->mm)
		return -EIO;
	switch (ioctl) {
	case KVM_GET_DIRTY_LOG: {
		struct compat_kvm_dirty_log compat_log;
		struct kvm_dirty_log log;

		if (copy_from_user(&compat_log, (void __user *)arg,
				   sizeof(compat_log)))
3884
			return -EFAULT;
3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899
		log.slot	 = compat_log.slot;
		log.padding1	 = compat_log.padding1;
		log.padding2	 = compat_log.padding2;
		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);

		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
		break;
	}
	default:
		r = kvm_vm_ioctl(filp, ioctl, arg);
	}
	return r;
}
#endif

3900
static struct file_operations kvm_vm_fops = {
3901 3902
	.release        = kvm_vm_release,
	.unlocked_ioctl = kvm_vm_ioctl,
3903
	.llseek		= noop_llseek,
3904
	KVM_COMPAT(kvm_vm_compat_ioctl),
3905 3906
};

3907
static int kvm_dev_ioctl_create_vm(unsigned long type)
3908
{
3909
	int r;
3910
	struct kvm *kvm;
3911
	struct file *file;
3912

3913
	kvm = kvm_create_vm(type);
3914 3915
	if (IS_ERR(kvm))
		return PTR_ERR(kvm);
3916
#ifdef CONFIG_KVM_MMIO
3917
	r = kvm_coalesced_mmio_init(kvm);
3918 3919
	if (r < 0)
		goto put_kvm;
3920
#endif
3921
	r = get_unused_fd_flags(O_CLOEXEC);
3922 3923 3924
	if (r < 0)
		goto put_kvm;

3925 3926 3927
	file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
	if (IS_ERR(file)) {
		put_unused_fd(r);
3928 3929
		r = PTR_ERR(file);
		goto put_kvm;
3930
	}
3931

3932 3933 3934 3935 3936 3937
	/*
	 * Don't call kvm_put_kvm anymore at this point; file->f_op is
	 * already set, with ->release() being kvm_vm_release().  In error
	 * cases it will be called by the final fput(file) and will take
	 * care of doing kvm_put_kvm(kvm).
	 */
3938
	if (kvm_create_vm_debugfs(kvm, r) < 0) {
3939 3940
		put_unused_fd(r);
		fput(file);
3941 3942
		return -ENOMEM;
	}
3943
	kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
3944

3945
	fd_install(r, file);
3946
	return r;
3947 3948 3949 3950

put_kvm:
	kvm_put_kvm(kvm);
	return r;
3951 3952 3953 3954 3955
}

static long kvm_dev_ioctl(struct file *filp,
			  unsigned int ioctl, unsigned long arg)
{
3956
	long r = -EINVAL;
3957 3958 3959

	switch (ioctl) {
	case KVM_GET_API_VERSION:
3960 3961
		if (arg)
			goto out;
3962 3963 3964
		r = KVM_API_VERSION;
		break;
	case KVM_CREATE_VM:
3965
		r = kvm_dev_ioctl_create_vm(arg);
3966
		break;
3967
	case KVM_CHECK_EXTENSION:
3968
		r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
3969
		break;
3970 3971 3972
	case KVM_GET_VCPU_MMAP_SIZE:
		if (arg)
			goto out;
3973 3974 3975
		r = PAGE_SIZE;     /* struct kvm_run */
#ifdef CONFIG_X86
		r += PAGE_SIZE;    /* pio data page */
3976
#endif
3977
#ifdef CONFIG_KVM_MMIO
3978
		r += PAGE_SIZE;    /* coalesced mmio ring page */
3979
#endif
3980
		break;
3981 3982 3983
	case KVM_TRACE_ENABLE:
	case KVM_TRACE_PAUSE:
	case KVM_TRACE_DISABLE:
3984
		r = -EOPNOTSUPP;
3985
		break;
A
Avi Kivity 已提交
3986
	default:
3987
		return kvm_arch_dev_ioctl(filp, ioctl, arg);
A
Avi Kivity 已提交
3988 3989 3990 3991 3992 3993 3994
	}
out:
	return r;
}

static struct file_operations kvm_chardev_ops = {
	.unlocked_ioctl = kvm_dev_ioctl,
3995
	.llseek		= noop_llseek,
3996
	KVM_COMPAT(kvm_dev_ioctl),
A
Avi Kivity 已提交
3997 3998 3999
};

static struct miscdevice kvm_dev = {
A
Avi Kivity 已提交
4000
	KVM_MINOR,
A
Avi Kivity 已提交
4001 4002 4003 4004
	"kvm",
	&kvm_chardev_ops,
};

4005
static void hardware_enable_nolock(void *junk)
4006 4007
{
	int cpu = raw_smp_processor_id();
4008
	int r;
4009

4010
	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
4011
		return;
4012

4013
	cpumask_set_cpu(cpu, cpus_hardware_enabled);
4014

4015
	r = kvm_arch_hardware_enable();
4016 4017 4018 4019

	if (r) {
		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
		atomic_inc(&hardware_enable_failed);
X
Xiubo Li 已提交
4020
		pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
4021
	}
4022 4023
}

4024
static int kvm_starting_cpu(unsigned int cpu)
4025
{
4026
	raw_spin_lock(&kvm_count_lock);
4027 4028
	if (kvm_usage_count)
		hardware_enable_nolock(NULL);
4029
	raw_spin_unlock(&kvm_count_lock);
4030
	return 0;
4031 4032 4033
}

static void hardware_disable_nolock(void *junk)
4034 4035 4036
{
	int cpu = raw_smp_processor_id();

4037
	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
4038
		return;
4039
	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
4040
	kvm_arch_hardware_disable();
4041 4042
}

4043
static int kvm_dying_cpu(unsigned int cpu)
4044
{
4045
	raw_spin_lock(&kvm_count_lock);
4046 4047
	if (kvm_usage_count)
		hardware_disable_nolock(NULL);
4048
	raw_spin_unlock(&kvm_count_lock);
4049
	return 0;
4050 4051
}

4052 4053 4054 4055 4056 4057
static void hardware_disable_all_nolock(void)
{
	BUG_ON(!kvm_usage_count);

	kvm_usage_count--;
	if (!kvm_usage_count)
4058
		on_each_cpu(hardware_disable_nolock, NULL, 1);
4059 4060 4061 4062
}

static void hardware_disable_all(void)
{
4063
	raw_spin_lock(&kvm_count_lock);
4064
	hardware_disable_all_nolock();
4065
	raw_spin_unlock(&kvm_count_lock);
4066 4067 4068 4069 4070 4071
}

static int hardware_enable_all(void)
{
	int r = 0;

4072
	raw_spin_lock(&kvm_count_lock);
4073 4074 4075 4076

	kvm_usage_count++;
	if (kvm_usage_count == 1) {
		atomic_set(&hardware_enable_failed, 0);
4077
		on_each_cpu(hardware_enable_nolock, NULL, 1);
4078 4079 4080 4081 4082 4083 4084

		if (atomic_read(&hardware_enable_failed)) {
			hardware_disable_all_nolock();
			r = -EBUSY;
		}
	}

4085
	raw_spin_unlock(&kvm_count_lock);
4086 4087 4088 4089

	return r;
}

4090
static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
M
Mike Day 已提交
4091
		      void *v)
4092
{
4093 4094 4095 4096 4097 4098
	/*
	 * Some (well, at least mine) BIOSes hang on reboot if
	 * in vmx root mode.
	 *
	 * And Intel TXT required VMX off for all cpu when system shutdown.
	 */
X
Xiubo Li 已提交
4099
	pr_info("kvm: exiting hardware virtualization\n");
4100
	kvm_rebooting = true;
4101
	on_each_cpu(hardware_disable_nolock, NULL, 1);
4102 4103 4104 4105 4106 4107 4108 4109
	return NOTIFY_OK;
}

static struct notifier_block kvm_reboot_notifier = {
	.notifier_call = kvm_reboot,
	.priority = 0,
};

M
Marcelo Tosatti 已提交
4110
static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
4111 4112 4113 4114
{
	int i;

	for (i = 0; i < bus->dev_count; i++) {
4115
		struct kvm_io_device *pos = bus->range[i].dev;
4116 4117 4118

		kvm_iodevice_destructor(pos);
	}
M
Marcelo Tosatti 已提交
4119
	kfree(bus);
4120 4121
}

4122
static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
X
Xiubo Li 已提交
4123
				 const struct kvm_io_range *r2)
4124
{
J
Jason Wang 已提交
4125 4126 4127 4128
	gpa_t addr1 = r1->addr;
	gpa_t addr2 = r2->addr;

	if (addr1 < addr2)
4129
		return -1;
J
Jason Wang 已提交
4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141

	/* If r2->len == 0, match the exact address.  If r2->len != 0,
	 * accept any overlapping write.  Any order is acceptable for
	 * overlapping ranges, because kvm_io_bus_get_first_dev ensures
	 * we process all of them.
	 */
	if (r2->len) {
		addr1 += r1->len;
		addr2 += r2->len;
	}

	if (addr1 > addr2)
4142
		return 1;
J
Jason Wang 已提交
4143

4144 4145 4146
	return 0;
}

4147 4148
static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
{
4149
	return kvm_io_bus_cmp(p1, p2);
4150 4151
}

G
Geoff Levand 已提交
4152
static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169
			     gpa_t addr, int len)
{
	struct kvm_io_range *range, key;
	int off;

	key = (struct kvm_io_range) {
		.addr = addr,
		.len = len,
	};

	range = bsearch(&key, bus->range, bus->dev_count,
			sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
	if (range == NULL)
		return -ENOENT;

	off = range - bus->range;

4170
	while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
4171 4172 4173 4174 4175
		off--;

	return off;
}

4176
static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
C
Cornelia Huck 已提交
4177 4178 4179 4180 4181 4182 4183 4184 4185
			      struct kvm_io_range *range, const void *val)
{
	int idx;

	idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
	if (idx < 0)
		return -EOPNOTSUPP;

	while (idx < bus->dev_count &&
4186
		kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
4187
		if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
C
Cornelia Huck 已提交
4188 4189 4190 4191 4192 4193 4194 4195
					range->len, val))
			return idx;
		idx++;
	}

	return -EOPNOTSUPP;
}

4196
/* kvm_io_bus_write - called under kvm->slots_lock */
4197
int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
4198
		     int len, const void *val)
4199
{
4200
	struct kvm_io_bus *bus;
4201
	struct kvm_io_range range;
C
Cornelia Huck 已提交
4202
	int r;
4203 4204 4205 4206 4207

	range = (struct kvm_io_range) {
		.addr = addr,
		.len = len,
	};
4208

4209
	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
4210 4211
	if (!bus)
		return -ENOMEM;
4212
	r = __kvm_io_bus_write(vcpu, bus, &range, val);
C
Cornelia Huck 已提交
4213 4214
	return r < 0 ? r : 0;
}
L
Leo Yan 已提交
4215
EXPORT_SYMBOL_GPL(kvm_io_bus_write);
C
Cornelia Huck 已提交
4216 4217

/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
4218 4219
int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
			    gpa_t addr, int len, const void *val, long cookie)
C
Cornelia Huck 已提交
4220 4221 4222 4223 4224 4225 4226 4227 4228
{
	struct kvm_io_bus *bus;
	struct kvm_io_range range;

	range = (struct kvm_io_range) {
		.addr = addr,
		.len = len,
	};

4229
	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
4230 4231
	if (!bus)
		return -ENOMEM;
C
Cornelia Huck 已提交
4232 4233 4234

	/* First try the device referenced by cookie. */
	if ((cookie >= 0) && (cookie < bus->dev_count) &&
4235
	    (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
4236
		if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
C
Cornelia Huck 已提交
4237 4238 4239 4240 4241 4242 4243
					val))
			return cookie;

	/*
	 * cookie contained garbage; fall back to search and return the
	 * correct cookie value.
	 */
4244
	return __kvm_io_bus_write(vcpu, bus, &range, val);
C
Cornelia Huck 已提交
4245 4246
}

4247 4248
static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
			     struct kvm_io_range *range, void *val)
C
Cornelia Huck 已提交
4249 4250 4251 4252
{
	int idx;

	idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
4253 4254 4255 4256
	if (idx < 0)
		return -EOPNOTSUPP;

	while (idx < bus->dev_count &&
4257
		kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
4258
		if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
C
Cornelia Huck 已提交
4259 4260
				       range->len, val))
			return idx;
4261 4262 4263
		idx++;
	}

4264 4265
	return -EOPNOTSUPP;
}
4266

4267
/* kvm_io_bus_read - called under kvm->slots_lock */
4268
int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
M
Marcelo Tosatti 已提交
4269
		    int len, void *val)
4270
{
4271
	struct kvm_io_bus *bus;
4272
	struct kvm_io_range range;
C
Cornelia Huck 已提交
4273
	int r;
4274 4275 4276 4277 4278

	range = (struct kvm_io_range) {
		.addr = addr,
		.len = len,
	};
M
Marcelo Tosatti 已提交
4279

4280
	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
4281 4282
	if (!bus)
		return -ENOMEM;
4283
	r = __kvm_io_bus_read(vcpu, bus, &range, val);
C
Cornelia Huck 已提交
4284 4285
	return r < 0 ? r : 0;
}
4286

4287
/* Caller must hold slots_lock. */
4288 4289
int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
			    int len, struct kvm_io_device *dev)
4290
{
4291
	int i;
M
Marcelo Tosatti 已提交
4292
	struct kvm_io_bus *new_bus, *bus;
4293
	struct kvm_io_range range;
4294

4295
	bus = kvm_get_bus(kvm, bus_idx);
4296 4297 4298
	if (!bus)
		return -ENOMEM;

4299 4300
	/* exclude ioeventfd which is limited by maximum fd */
	if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
4301
		return -ENOSPC;
4302

4303
	new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1),
4304
			  GFP_KERNEL_ACCOUNT);
M
Marcelo Tosatti 已提交
4305 4306
	if (!new_bus)
		return -ENOMEM;
4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322

	range = (struct kvm_io_range) {
		.addr = addr,
		.len = len,
		.dev = dev,
	};

	for (i = 0; i < bus->dev_count; i++)
		if (kvm_io_bus_cmp(&bus->range[i], &range) > 0)
			break;

	memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
	new_bus->dev_count++;
	new_bus->range[i] = range;
	memcpy(new_bus->range + i + 1, bus->range + i,
		(bus->dev_count - i) * sizeof(struct kvm_io_range));
M
Marcelo Tosatti 已提交
4323 4324 4325
	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
	synchronize_srcu_expedited(&kvm->srcu);
	kfree(bus);
4326 4327 4328 4329

	return 0;
}

4330
/* Caller must hold slots_lock. */
4331 4332
void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
			       struct kvm_io_device *dev)
4333
{
4334
	int i;
M
Marcelo Tosatti 已提交
4335
	struct kvm_io_bus *new_bus, *bus;
4336

4337
	bus = kvm_get_bus(kvm, bus_idx);
4338
	if (!bus)
4339
		return;
4340

4341 4342
	for (i = 0; i < bus->dev_count; i++)
		if (bus->range[i].dev == dev) {
4343 4344
			break;
		}
M
Marcelo Tosatti 已提交
4345

4346 4347
	if (i == bus->dev_count)
		return;
4348

4349
	new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
4350
			  GFP_KERNEL_ACCOUNT);
4351 4352 4353 4354
	if (!new_bus)  {
		pr_err("kvm: failed to shrink bus, removing it completely\n");
		goto broken;
	}
4355 4356 4357 4358 4359

	memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
	new_bus->dev_count--;
	memcpy(new_bus->range + i, bus->range + i + 1,
	       (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
M
Marcelo Tosatti 已提交
4360

4361
broken:
M
Marcelo Tosatti 已提交
4362 4363 4364
	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
	synchronize_srcu_expedited(&kvm->srcu);
	kfree(bus);
4365
	return;
4366 4367
}

4368 4369 4370 4371 4372 4373 4374 4375 4376 4377
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
					 gpa_t addr)
{
	struct kvm_io_bus *bus;
	int dev_idx, srcu_idx;
	struct kvm_io_device *iodev = NULL;

	srcu_idx = srcu_read_lock(&kvm->srcu);

	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
4378 4379
	if (!bus)
		goto out_unlock;
4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393

	dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1);
	if (dev_idx < 0)
		goto out_unlock;

	iodev = bus->range[dev_idx].dev;

out_unlock:
	srcu_read_unlock(&kvm->srcu, srcu_idx);

	return iodev;
}
EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);

4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405
static int kvm_debugfs_open(struct inode *inode, struct file *file,
			   int (*get)(void *, u64 *), int (*set)(void *, u64),
			   const char *fmt)
{
	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
					  inode->i_private;

	/* The debugfs files are a reference to the kvm struct which
	 * is still valid when kvm_destroy_vm is called.
	 * To avoid the race between open and the removal of the debugfs
	 * directory we test against the users count.
	 */
4406
	if (!refcount_inc_not_zero(&stat_data->kvm->users_count))
4407 4408
		return -ENOENT;

4409
	if (simple_attr_open(inode, file, get,
4410 4411 4412
		    KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222
		    ? set : NULL,
		    fmt)) {
4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430
		kvm_put_kvm(stat_data->kvm);
		return -ENOMEM;
	}

	return 0;
}

static int kvm_debugfs_release(struct inode *inode, struct file *file)
{
	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
					  inode->i_private;

	simple_attr_release(inode, file);
	kvm_put_kvm(stat_data->kvm);

	return 0;
}

4431
static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
4432
{
4433
	*val = *(ulong *)((void *)kvm + offset);
4434

4435 4436 4437 4438 4439 4440
	return 0;
}

static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
{
	*(ulong *)((void *)kvm + offset) = 0;
4441 4442 4443 4444

	return 0;
}

4445
static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
4446
{
4447 4448
	int i;
	struct kvm_vcpu *vcpu;
4449

4450
	*val = 0;
4451

4452 4453
	kvm_for_each_vcpu(i, vcpu, kvm)
		*val += *(u64 *)((void *)vcpu + offset);
4454 4455 4456 4457

	return 0;
}

4458
static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
4459
{
4460 4461
	int i;
	struct kvm_vcpu *vcpu;
4462

4463 4464 4465 4466 4467
	kvm_for_each_vcpu(i, vcpu, kvm)
		*(u64 *)((void *)vcpu + offset) = 0;

	return 0;
}
4468

4469
static int kvm_stat_data_get(void *data, u64 *val)
4470
{
4471
	int r = -EFAULT;
4472 4473
	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;

4474 4475 4476 4477 4478 4479 4480 4481 4482 4483
	switch (stat_data->dbgfs_item->kind) {
	case KVM_STAT_VM:
		r = kvm_get_stat_per_vm(stat_data->kvm,
					stat_data->dbgfs_item->offset, val);
		break;
	case KVM_STAT_VCPU:
		r = kvm_get_stat_per_vcpu(stat_data->kvm,
					  stat_data->dbgfs_item->offset, val);
		break;
	}
4484

4485
	return r;
4486 4487
}

4488
static int kvm_stat_data_clear(void *data, u64 val)
4489
{
4490
	int r = -EFAULT;
4491 4492 4493 4494 4495
	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;

	if (val)
		return -EINVAL;

4496 4497 4498 4499 4500 4501 4502 4503 4504 4505
	switch (stat_data->dbgfs_item->kind) {
	case KVM_STAT_VM:
		r = kvm_clear_stat_per_vm(stat_data->kvm,
					  stat_data->dbgfs_item->offset);
		break;
	case KVM_STAT_VCPU:
		r = kvm_clear_stat_per_vcpu(stat_data->kvm,
					    stat_data->dbgfs_item->offset);
		break;
	}
4506

4507
	return r;
4508 4509
}

4510
static int kvm_stat_data_open(struct inode *inode, struct file *file)
4511 4512
{
	__simple_attr_check_format("%llu\n", 0ull);
4513 4514
	return kvm_debugfs_open(inode, file, kvm_stat_data_get,
				kvm_stat_data_clear, "%llu\n");
4515 4516
}

4517 4518 4519
static const struct file_operations stat_fops_per_vm = {
	.owner = THIS_MODULE,
	.open = kvm_stat_data_open,
4520
	.release = kvm_debugfs_release,
4521 4522 4523
	.read = simple_attr_read,
	.write = simple_attr_write,
	.llseek = no_llseek,
4524 4525
};

4526
static int vm_stat_get(void *_offset, u64 *val)
4527 4528 4529
{
	unsigned offset = (long)_offset;
	struct kvm *kvm;
4530
	u64 tmp_val;
4531

4532
	*val = 0;
J
Junaid Shahid 已提交
4533
	mutex_lock(&kvm_lock);
4534
	list_for_each_entry(kvm, &vm_list, vm_list) {
4535
		kvm_get_stat_per_vm(kvm, offset, &tmp_val);
4536 4537
		*val += tmp_val;
	}
J
Junaid Shahid 已提交
4538
	mutex_unlock(&kvm_lock);
4539
	return 0;
4540 4541
}

4542 4543 4544 4545 4546 4547 4548 4549
static int vm_stat_clear(void *_offset, u64 val)
{
	unsigned offset = (long)_offset;
	struct kvm *kvm;

	if (val)
		return -EINVAL;

J
Junaid Shahid 已提交
4550
	mutex_lock(&kvm_lock);
4551
	list_for_each_entry(kvm, &vm_list, vm_list) {
4552
		kvm_clear_stat_per_vm(kvm, offset);
4553
	}
J
Junaid Shahid 已提交
4554
	mutex_unlock(&kvm_lock);
4555 4556 4557 4558 4559

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
4560

4561
static int vcpu_stat_get(void *_offset, u64 *val)
A
Avi Kivity 已提交
4562 4563 4564
{
	unsigned offset = (long)_offset;
	struct kvm *kvm;
4565
	u64 tmp_val;
A
Avi Kivity 已提交
4566

4567
	*val = 0;
J
Junaid Shahid 已提交
4568
	mutex_lock(&kvm_lock);
4569
	list_for_each_entry(kvm, &vm_list, vm_list) {
4570
		kvm_get_stat_per_vcpu(kvm, offset, &tmp_val);
4571 4572
		*val += tmp_val;
	}
J
Junaid Shahid 已提交
4573
	mutex_unlock(&kvm_lock);
4574
	return 0;
A
Avi Kivity 已提交
4575 4576
}

4577 4578 4579 4580 4581 4582 4583 4584
static int vcpu_stat_clear(void *_offset, u64 val)
{
	unsigned offset = (long)_offset;
	struct kvm *kvm;

	if (val)
		return -EINVAL;

J
Junaid Shahid 已提交
4585
	mutex_lock(&kvm_lock);
4586
	list_for_each_entry(kvm, &vm_list, vm_list) {
4587
		kvm_clear_stat_per_vcpu(kvm, offset);
4588
	}
J
Junaid Shahid 已提交
4589
	mutex_unlock(&kvm_lock);
4590 4591 4592 4593 4594 4595

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
			"%llu\n");
4596

4597
static const struct file_operations *stat_fops[] = {
4598 4599 4600
	[KVM_STAT_VCPU] = &vcpu_stat_fops,
	[KVM_STAT_VM]   = &vm_stat_fops,
};
A
Avi Kivity 已提交
4601

4602 4603 4604 4605 4606 4607 4608 4609
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
{
	struct kobj_uevent_env *env;
	unsigned long long created, active;

	if (!kvm_dev.this_device || !kvm)
		return;

J
Junaid Shahid 已提交
4610
	mutex_lock(&kvm_lock);
4611 4612 4613 4614 4615 4616 4617 4618
	if (type == KVM_EVENT_CREATE_VM) {
		kvm_createvm_count++;
		kvm_active_vms++;
	} else if (type == KVM_EVENT_DESTROY_VM) {
		kvm_active_vms--;
	}
	created = kvm_createvm_count;
	active = kvm_active_vms;
J
Junaid Shahid 已提交
4619
	mutex_unlock(&kvm_lock);
4620

4621
	env = kzalloc(sizeof(*env), GFP_KERNEL_ACCOUNT);
4622 4623 4624 4625 4626 4627
	if (!env)
		return;

	add_uevent_var(env, "CREATED=%llu", created);
	add_uevent_var(env, "COUNT=%llu", active);

4628
	if (type == KVM_EVENT_CREATE_VM) {
4629
		add_uevent_var(env, "EVENT=create");
4630 4631
		kvm->userspace_pid = task_pid_nr(current);
	} else if (type == KVM_EVENT_DESTROY_VM) {
4632
		add_uevent_var(env, "EVENT=destroy");
4633 4634
	}
	add_uevent_var(env, "PID=%d", kvm->userspace_pid);
4635

4636
	if (!IS_ERR_OR_NULL(kvm->debugfs_dentry)) {
4637
		char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
4638 4639 4640 4641 4642 4643

		if (p) {
			tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
			if (!IS_ERR(tmp))
				add_uevent_var(env, "STATS_PATH=%s", tmp);
			kfree(p);
4644 4645 4646 4647 4648 4649 4650 4651
		}
	}
	/* no need for checks, since we are adding at most only 5 keys */
	env->envp[env->envp_idx++] = NULL;
	kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp);
	kfree(env);
}

4652
static void kvm_init_debug(void)
A
Avi Kivity 已提交
4653 4654 4655
{
	struct kvm_stats_debugfs_item *p;

4656
	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
4657

4658 4659
	kvm_debugfs_num_entries = 0;
	for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
4660 4661
		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
				    kvm_debugfs_dir, (void *)(long)p->offset,
4662
				    stat_fops[p->kind]);
4663
	}
A
Avi Kivity 已提交
4664 4665
}

4666
static int kvm_suspend(void)
4667
{
4668
	if (kvm_usage_count)
4669
		hardware_disable_nolock(NULL);
4670 4671 4672
	return 0;
}

4673
static void kvm_resume(void)
4674
{
4675
	if (kvm_usage_count) {
4676 4677 4678
#ifdef CONFIG_LOCKDEP
		WARN_ON(lockdep_is_held(&kvm_count_lock));
#endif
4679
		hardware_enable_nolock(NULL);
4680
	}
4681 4682
}

4683
static struct syscore_ops kvm_syscore_ops = {
4684 4685 4686 4687
	.suspend = kvm_suspend,
	.resume = kvm_resume,
};

4688 4689 4690 4691 4692 4693 4694 4695 4696
static inline
struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
{
	return container_of(pn, struct kvm_vcpu, preempt_notifier);
}

static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
{
	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
4697

4698
	WRITE_ONCE(vcpu->preempted, false);
4699
	WRITE_ONCE(vcpu->ready, false);
4700

4701
	__this_cpu_write(kvm_running_vcpu, vcpu);
R
Radim Krčmář 已提交
4702
	kvm_arch_sched_in(vcpu, cpu);
4703
	kvm_arch_vcpu_load(vcpu, cpu);
4704 4705 4706 4707 4708 4709 4710
}

static void kvm_sched_out(struct preempt_notifier *pn,
			  struct task_struct *next)
{
	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);

4711
	if (current->state == TASK_RUNNING) {
4712
		WRITE_ONCE(vcpu->preempted, true);
4713 4714
		WRITE_ONCE(vcpu->ready, true);
	}
4715
	kvm_arch_vcpu_put(vcpu);
4716 4717 4718 4719 4720
	__this_cpu_write(kvm_running_vcpu, NULL);
}

/**
 * kvm_get_running_vcpu - get the vcpu running on the current CPU.
4721 4722 4723 4724 4725 4726
 *
 * We can disable preemption locally around accessing the per-CPU variable,
 * and use the resolved vcpu pointer after enabling preemption again,
 * because even if the current thread is migrated to another CPU, reading
 * the per-CPU value later will give us the same value as we update the
 * per-CPU variable in the preempt notifier handlers.
4727 4728 4729
 */
struct kvm_vcpu *kvm_get_running_vcpu(void)
{
4730 4731 4732 4733 4734 4735 4736
	struct kvm_vcpu *vcpu;

	preempt_disable();
	vcpu = __this_cpu_read(kvm_running_vcpu);
	preempt_enable();

	return vcpu;
4737
}
4738
EXPORT_SYMBOL_GPL(kvm_get_running_vcpu);
4739 4740 4741 4742 4743 4744 4745

/**
 * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus.
 */
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
{
        return &kvm_running_vcpu;
4746 4747
}

4748 4749 4750 4751 4752 4753
struct kvm_cpu_compat_check {
	void *opaque;
	int *ret;
};

static void check_processor_compat(void *data)
4754
{
4755 4756 4757
	struct kvm_cpu_compat_check *c = data;

	*c->ret = kvm_arch_check_processor_compat(c->opaque);
4758 4759
}

4760
int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
4761
		  struct module *module)
A
Avi Kivity 已提交
4762
{
4763
	struct kvm_cpu_compat_check c;
A
Avi Kivity 已提交
4764
	int r;
Y
Yang, Sheng 已提交
4765
	int cpu;
A
Avi Kivity 已提交
4766

4767 4768
	r = kvm_arch_init(opaque);
	if (r)
4769
		goto out_fail;
4770

4771 4772 4773 4774
	/*
	 * kvm_arch_init makes sure there's at most one caller
	 * for architectures that support multiple implementations,
	 * like intel and amd on x86.
P
Paolo Bonzini 已提交
4775 4776
	 * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
	 * conflicts in case kvm is already setup for another implementation.
4777
	 */
P
Paolo Bonzini 已提交
4778 4779 4780
	r = kvm_irqfd_init();
	if (r)
		goto out_irqfd;
4781

4782
	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
4783 4784 4785 4786
		r = -ENOMEM;
		goto out_free_0;
	}

4787
	r = kvm_arch_hardware_setup(opaque);
A
Avi Kivity 已提交
4788
	if (r < 0)
4789
		goto out_free_1;
A
Avi Kivity 已提交
4790

4791 4792
	c.ret = &r;
	c.opaque = opaque;
Y
Yang, Sheng 已提交
4793
	for_each_online_cpu(cpu) {
4794
		smp_call_function_single(cpu, check_processor_compat, &c, 1);
Y
Yang, Sheng 已提交
4795
		if (r < 0)
4796
			goto out_free_2;
Y
Yang, Sheng 已提交
4797 4798
	}

T
Thomas Gleixner 已提交
4799
	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
4800
				      kvm_starting_cpu, kvm_dying_cpu);
A
Avi Kivity 已提交
4801
	if (r)
4802
		goto out_free_2;
A
Avi Kivity 已提交
4803 4804
	register_reboot_notifier(&kvm_reboot_notifier);

4805
	/* A kmem cache lets us meet the alignment requirements of fx_save. */
4806 4807
	if (!vcpu_align)
		vcpu_align = __alignof__(struct kvm_vcpu);
4808 4809 4810 4811 4812 4813
	kvm_vcpu_cache =
		kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
					   SLAB_ACCOUNT,
					   offsetof(struct kvm_vcpu, arch),
					   sizeof_field(struct kvm_vcpu, arch),
					   NULL);
4814 4815
	if (!kvm_vcpu_cache) {
		r = -ENOMEM;
4816
		goto out_free_3;
4817 4818
	}

4819 4820 4821 4822
	r = kvm_async_pf_init();
	if (r)
		goto out_free;

A
Avi Kivity 已提交
4823
	kvm_chardev_ops.owner = module;
4824 4825
	kvm_vm_fops.owner = module;
	kvm_vcpu_fops.owner = module;
A
Avi Kivity 已提交
4826 4827 4828

	r = misc_register(&kvm_dev);
	if (r) {
X
Xiubo Li 已提交
4829
		pr_err("kvm: misc device register failed\n");
4830
		goto out_unreg;
A
Avi Kivity 已提交
4831 4832
	}

4833 4834
	register_syscore_ops(&kvm_syscore_ops);

4835 4836 4837
	kvm_preempt_ops.sched_in = kvm_sched_in;
	kvm_preempt_ops.sched_out = kvm_sched_out;

4838
	kvm_init_debug();
4839

P
Paolo Bonzini 已提交
4840 4841 4842
	r = kvm_vfio_ops_init();
	WARN_ON(r);

4843
	return 0;
A
Avi Kivity 已提交
4844

4845 4846
out_unreg:
	kvm_async_pf_deinit();
A
Avi Kivity 已提交
4847
out_free:
4848
	kmem_cache_destroy(kvm_vcpu_cache);
4849
out_free_3:
A
Avi Kivity 已提交
4850
	unregister_reboot_notifier(&kvm_reboot_notifier);
4851
	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
4852
out_free_2:
4853
	kvm_arch_hardware_unsetup();
4854
out_free_1:
4855
	free_cpumask_var(cpus_hardware_enabled);
4856
out_free_0:
4857
	kvm_irqfd_exit();
P
Paolo Bonzini 已提交
4858
out_irqfd:
4859 4860
	kvm_arch_exit();
out_fail:
A
Avi Kivity 已提交
4861 4862
	return r;
}
4863
EXPORT_SYMBOL_GPL(kvm_init);
A
Avi Kivity 已提交
4864

4865
void kvm_exit(void)
A
Avi Kivity 已提交
4866
{
4867
	debugfs_remove_recursive(kvm_debugfs_dir);
A
Avi Kivity 已提交
4868
	misc_deregister(&kvm_dev);
4869
	kmem_cache_destroy(kvm_vcpu_cache);
4870
	kvm_async_pf_deinit();
4871
	unregister_syscore_ops(&kvm_syscore_ops);
A
Avi Kivity 已提交
4872
	unregister_reboot_notifier(&kvm_reboot_notifier);
4873
	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
4874
	on_each_cpu(hardware_disable_nolock, NULL, 1);
4875
	kvm_arch_hardware_unsetup();
4876
	kvm_arch_exit();
4877
	kvm_irqfd_exit();
4878
	free_cpumask_var(cpus_hardware_enabled);
4879
	kvm_vfio_ops_exit();
A
Avi Kivity 已提交
4880
}
4881
EXPORT_SYMBOL_GPL(kvm_exit);
4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964

struct kvm_vm_worker_thread_context {
	struct kvm *kvm;
	struct task_struct *parent;
	struct completion init_done;
	kvm_vm_thread_fn_t thread_fn;
	uintptr_t data;
	int err;
};

static int kvm_vm_worker_thread(void *context)
{
	/*
	 * The init_context is allocated on the stack of the parent thread, so
	 * we have to locally copy anything that is needed beyond initialization
	 */
	struct kvm_vm_worker_thread_context *init_context = context;
	struct kvm *kvm = init_context->kvm;
	kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
	uintptr_t data = init_context->data;
	int err;

	err = kthread_park(current);
	/* kthread_park(current) is never supposed to return an error */
	WARN_ON(err != 0);
	if (err)
		goto init_complete;

	err = cgroup_attach_task_all(init_context->parent, current);
	if (err) {
		kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
			__func__, err);
		goto init_complete;
	}

	set_user_nice(current, task_nice(init_context->parent));

init_complete:
	init_context->err = err;
	complete(&init_context->init_done);
	init_context = NULL;

	if (err)
		return err;

	/* Wait to be woken up by the spawner before proceeding. */
	kthread_parkme();

	if (!kthread_should_stop())
		err = thread_fn(kvm, data);

	return err;
}

int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
				uintptr_t data, const char *name,
				struct task_struct **thread_ptr)
{
	struct kvm_vm_worker_thread_context init_context = {};
	struct task_struct *thread;

	*thread_ptr = NULL;
	init_context.kvm = kvm;
	init_context.parent = current;
	init_context.thread_fn = thread_fn;
	init_context.data = data;
	init_completion(&init_context.init_done);

	thread = kthread_run(kvm_vm_worker_thread, &init_context,
			     "%s-%d", name, task_pid_nr(current));
	if (IS_ERR(thread))
		return PTR_ERR(thread);

	/* kthread_run is never supposed to return NULL */
	WARN_ON(thread == NULL);

	wait_for_completion(&init_context.init_done);

	if (!init_context.err)
		*thread_ptr = thread;

	return init_context.err;
}