mmu.c 53.0 KB
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/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
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#include <linux/mman.h>
#include <linux/kvm_host.h>
#include <linux/io.h>
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#include <linux/hugetlb.h>
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#include <linux/sched/signal.h>
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#include <trace/events/kvm.h>
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#include <asm/pgalloc.h>
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#include <asm/cacheflush.h>
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#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
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#include <asm/kvm_mmio.h>
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#include <asm/kvm_asm.h>
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#include <asm/kvm_emulate.h>
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#include <asm/virt.h>
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#include <asm/system_misc.h>
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#include "trace.h"
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static pgd_t *boot_hyp_pgd;
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static pgd_t *hyp_pgd;
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static pgd_t *merged_hyp_pgd;
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static DEFINE_MUTEX(kvm_hyp_pgd_mutex);

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static unsigned long hyp_idmap_start;
static unsigned long hyp_idmap_end;
static phys_addr_t hyp_idmap_vector;

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#define S2_PGD_SIZE	(PTRS_PER_S2_PGD * sizeof(pgd_t))
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#define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
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#define KVM_S2PTE_FLAG_IS_IOMAP		(1UL << 0)
#define KVM_S2_FLAG_LOGGING_ACTIVE	(1UL << 1)

static bool memslot_is_logging(struct kvm_memory_slot *memslot)
{
	return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
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}

/**
 * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
 * @kvm:	pointer to kvm structure.
 *
 * Interface to HYP function to flush all VM TLB entries
 */
void kvm_flush_remote_tlbs(struct kvm *kvm)
{
	kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
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}
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static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
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{
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	kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
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}

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/*
 * D-Cache management functions. They take the page table entries by
 * value, as they are flushing the cache using the kernel mapping (or
 * kmap on 32bit).
 */
static void kvm_flush_dcache_pte(pte_t pte)
{
	__kvm_flush_dcache_pte(pte);
}

static void kvm_flush_dcache_pmd(pmd_t pmd)
{
	__kvm_flush_dcache_pmd(pmd);
}

static void kvm_flush_dcache_pud(pud_t pud)
{
	__kvm_flush_dcache_pud(pud);
}

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static bool kvm_is_device_pfn(unsigned long pfn)
{
	return !pfn_valid(pfn);
}

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/**
 * stage2_dissolve_pmd() - clear and flush huge PMD entry
 * @kvm:	pointer to kvm structure.
 * @addr:	IPA
 * @pmd:	pmd pointer for IPA
 *
 * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
 * pages in the range dirty.
 */
static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
{
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	if (!pmd_thp_or_huge(*pmd))
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		return;

	pmd_clear(pmd);
	kvm_tlb_flush_vmid_ipa(kvm, addr);
	put_page(virt_to_page(pmd));
}

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static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
				  int min, int max)
{
	void *page;

	BUG_ON(max > KVM_NR_MEM_OBJS);
	if (cache->nobjs >= min)
		return 0;
	while (cache->nobjs < max) {
		page = (void *)__get_free_page(PGALLOC_GFP);
		if (!page)
			return -ENOMEM;
		cache->objects[cache->nobjs++] = page;
	}
	return 0;
}

static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
{
	while (mc->nobjs)
		free_page((unsigned long)mc->objects[--mc->nobjs]);
}

static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
{
	void *p;

	BUG_ON(!mc || !mc->nobjs);
	p = mc->objects[--mc->nobjs];
	return p;
}

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static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
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{
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	pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
	stage2_pgd_clear(pgd);
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	kvm_tlb_flush_vmid_ipa(kvm, addr);
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	stage2_pud_free(pud_table);
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	put_page(virt_to_page(pgd));
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}

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static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
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{
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	pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
	VM_BUG_ON(stage2_pud_huge(*pud));
	stage2_pud_clear(pud);
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	kvm_tlb_flush_vmid_ipa(kvm, addr);
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	stage2_pmd_free(pmd_table);
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	put_page(virt_to_page(pud));
}
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static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
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{
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	pte_t *pte_table = pte_offset_kernel(pmd, 0);
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	VM_BUG_ON(pmd_thp_or_huge(*pmd));
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	pmd_clear(pmd);
	kvm_tlb_flush_vmid_ipa(kvm, addr);
	pte_free_kernel(NULL, pte_table);
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	put_page(virt_to_page(pmd));
}

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/*
 * Unmapping vs dcache management:
 *
 * If a guest maps certain memory pages as uncached, all writes will
 * bypass the data cache and go directly to RAM.  However, the CPUs
 * can still speculate reads (not writes) and fill cache lines with
 * data.
 *
 * Those cache lines will be *clean* cache lines though, so a
 * clean+invalidate operation is equivalent to an invalidate
 * operation, because no cache lines are marked dirty.
 *
 * Those clean cache lines could be filled prior to an uncached write
 * by the guest, and the cache coherent IO subsystem would therefore
 * end up writing old data to disk.
 *
 * This is why right after unmapping a page/section and invalidating
 * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
 * the IO subsystem will never hit in the cache.
 */
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static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
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		       phys_addr_t addr, phys_addr_t end)
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{
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	phys_addr_t start_addr = addr;
	pte_t *pte, *start_pte;

	start_pte = pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
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			pte_t old_pte = *pte;

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			kvm_set_pte(pte, __pte(0));
			kvm_tlb_flush_vmid_ipa(kvm, addr);
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			/* No need to invalidate the cache for device mappings */
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			if (!kvm_is_device_pfn(pte_pfn(old_pte)))
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				kvm_flush_dcache_pte(old_pte);

			put_page(virt_to_page(pte));
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		}
	} while (pte++, addr += PAGE_SIZE, addr != end);

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	if (stage2_pte_table_empty(start_pte))
		clear_stage2_pmd_entry(kvm, pmd, start_addr);
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}

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static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
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		       phys_addr_t addr, phys_addr_t end)
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{
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	phys_addr_t next, start_addr = addr;
	pmd_t *pmd, *start_pmd;
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	start_pmd = pmd = stage2_pmd_offset(pud, addr);
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	do {
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		next = stage2_pmd_addr_end(addr, end);
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		if (!pmd_none(*pmd)) {
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			if (pmd_thp_or_huge(*pmd)) {
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				pmd_t old_pmd = *pmd;

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				pmd_clear(pmd);
				kvm_tlb_flush_vmid_ipa(kvm, addr);
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				kvm_flush_dcache_pmd(old_pmd);

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				put_page(virt_to_page(pmd));
			} else {
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				unmap_stage2_ptes(kvm, pmd, addr, next);
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			}
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		}
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	} while (pmd++, addr = next, addr != end);
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	if (stage2_pmd_table_empty(start_pmd))
		clear_stage2_pud_entry(kvm, pud, start_addr);
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}
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static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
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		       phys_addr_t addr, phys_addr_t end)
{
	phys_addr_t next, start_addr = addr;
	pud_t *pud, *start_pud;
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	start_pud = pud = stage2_pud_offset(pgd, addr);
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	do {
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		next = stage2_pud_addr_end(addr, end);
		if (!stage2_pud_none(*pud)) {
			if (stage2_pud_huge(*pud)) {
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				pud_t old_pud = *pud;

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				stage2_pud_clear(pud);
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				kvm_tlb_flush_vmid_ipa(kvm, addr);
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				kvm_flush_dcache_pud(old_pud);
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				put_page(virt_to_page(pud));
			} else {
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				unmap_stage2_pmds(kvm, pud, addr, next);
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			}
		}
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	} while (pud++, addr = next, addr != end);
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	if (stage2_pud_table_empty(start_pud))
		clear_stage2_pgd_entry(kvm, pgd, start_addr);
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}

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/**
 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
 * @kvm:   The VM pointer
 * @start: The intermediate physical base address of the range to unmap
 * @size:  The size of the area to unmap
 *
 * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
 * destroying the VM), otherwise another faulting VCPU may come in and mess
 * with things behind our backs.
 */
static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
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{
	pgd_t *pgd;
	phys_addr_t addr = start, end = start + size;
	phys_addr_t next;

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	assert_spin_locked(&kvm->mmu_lock);
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	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
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	do {
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		/*
		 * Make sure the page table is still active, as another thread
		 * could have possibly freed the page table, while we released
		 * the lock.
		 */
		if (!READ_ONCE(kvm->arch.pgd))
			break;
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		next = stage2_pgd_addr_end(addr, end);
		if (!stage2_pgd_none(*pgd))
			unmap_stage2_puds(kvm, pgd, addr, next);
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		/*
		 * If the range is too large, release the kvm->mmu_lock
		 * to prevent starvation and lockup detector warnings.
		 */
		if (next != end)
			cond_resched_lock(&kvm->mmu_lock);
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	} while (pgd++, addr = next, addr != end);
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}

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static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
			      phys_addr_t addr, phys_addr_t end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
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		if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
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			kvm_flush_dcache_pte(*pte);
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	} while (pte++, addr += PAGE_SIZE, addr != end);
}

static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
			      phys_addr_t addr, phys_addr_t end)
{
	pmd_t *pmd;
	phys_addr_t next;

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	pmd = stage2_pmd_offset(pud, addr);
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	do {
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		next = stage2_pmd_addr_end(addr, end);
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		if (!pmd_none(*pmd)) {
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			if (pmd_thp_or_huge(*pmd))
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				kvm_flush_dcache_pmd(*pmd);
			else
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				stage2_flush_ptes(kvm, pmd, addr, next);
		}
	} while (pmd++, addr = next, addr != end);
}

static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
			      phys_addr_t addr, phys_addr_t end)
{
	pud_t *pud;
	phys_addr_t next;

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	pud = stage2_pud_offset(pgd, addr);
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	do {
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		next = stage2_pud_addr_end(addr, end);
		if (!stage2_pud_none(*pud)) {
			if (stage2_pud_huge(*pud))
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				kvm_flush_dcache_pud(*pud);
			else
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				stage2_flush_pmds(kvm, pud, addr, next);
		}
	} while (pud++, addr = next, addr != end);
}

static void stage2_flush_memslot(struct kvm *kvm,
				 struct kvm_memory_slot *memslot)
{
	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
	phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
	phys_addr_t next;
	pgd_t *pgd;

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	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
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	do {
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		next = stage2_pgd_addr_end(addr, end);
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		stage2_flush_puds(kvm, pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

/**
 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
 * @kvm: The struct kvm pointer
 *
 * Go through the stage 2 page tables and invalidate any cache lines
 * backing memory already mapped to the VM.
 */
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static void stage2_flush_vm(struct kvm *kvm)
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{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;
	int idx;

	idx = srcu_read_lock(&kvm->srcu);
	spin_lock(&kvm->mmu_lock);

	slots = kvm_memslots(kvm);
	kvm_for_each_memslot(memslot, slots)
		stage2_flush_memslot(kvm, memslot);

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

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static void clear_hyp_pgd_entry(pgd_t *pgd)
{
	pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
	pgd_clear(pgd);
	pud_free(NULL, pud_table);
	put_page(virt_to_page(pgd));
}

static void clear_hyp_pud_entry(pud_t *pud)
{
	pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
	VM_BUG_ON(pud_huge(*pud));
	pud_clear(pud);
	pmd_free(NULL, pmd_table);
	put_page(virt_to_page(pud));
}

static void clear_hyp_pmd_entry(pmd_t *pmd)
{
	pte_t *pte_table = pte_offset_kernel(pmd, 0);
	VM_BUG_ON(pmd_thp_or_huge(*pmd));
	pmd_clear(pmd);
	pte_free_kernel(NULL, pte_table);
	put_page(virt_to_page(pmd));
}

static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
{
	pte_t *pte, *start_pte;

	start_pte = pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
			kvm_set_pte(pte, __pte(0));
			put_page(virt_to_page(pte));
		}
	} while (pte++, addr += PAGE_SIZE, addr != end);

	if (hyp_pte_table_empty(start_pte))
		clear_hyp_pmd_entry(pmd);
}

static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
{
	phys_addr_t next;
	pmd_t *pmd, *start_pmd;

	start_pmd = pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		/* Hyp doesn't use huge pmds */
		if (!pmd_none(*pmd))
			unmap_hyp_ptes(pmd, addr, next);
	} while (pmd++, addr = next, addr != end);

	if (hyp_pmd_table_empty(start_pmd))
		clear_hyp_pud_entry(pud);
}

static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
{
	phys_addr_t next;
	pud_t *pud, *start_pud;

	start_pud = pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
		/* Hyp doesn't use huge puds */
		if (!pud_none(*pud))
			unmap_hyp_pmds(pud, addr, next);
	} while (pud++, addr = next, addr != end);

	if (hyp_pud_table_empty(start_pud))
		clear_hyp_pgd_entry(pgd);
}

static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
{
	pgd_t *pgd;
	phys_addr_t addr = start, end = start + size;
	phys_addr_t next;

	/*
	 * We don't unmap anything from HYP, except at the hyp tear down.
	 * Hence, we don't have to invalidate the TLBs here.
	 */
	pgd = pgdp + pgd_index(addr);
	do {
		next = pgd_addr_end(addr, end);
		if (!pgd_none(*pgd))
			unmap_hyp_puds(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

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/**
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 * free_hyp_pgds - free Hyp-mode page tables
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 *
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 * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
 * therefore contains either mappings in the kernel memory area (above
 * PAGE_OFFSET), or device mappings in the vmalloc range (from
 * VMALLOC_START to VMALLOC_END).
 *
 * boot_hyp_pgd should only map two pages for the init code.
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 */
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void free_hyp_pgds(void)
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{
	unsigned long addr;

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	mutex_lock(&kvm_hyp_pgd_mutex);
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	if (boot_hyp_pgd) {
		unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
		free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
		boot_hyp_pgd = NULL;
	}

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	if (hyp_pgd) {
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		unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
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		for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
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Marc Zyngier 已提交
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			unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
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		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
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Marc Zyngier 已提交
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			unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
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		free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
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		hyp_pgd = NULL;
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	}
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	if (merged_hyp_pgd) {
		clear_page(merged_hyp_pgd);
		free_page((unsigned long)merged_hyp_pgd);
		merged_hyp_pgd = NULL;
	}
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	mutex_unlock(&kvm_hyp_pgd_mutex);
}

static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
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				    unsigned long end, unsigned long pfn,
				    pgprot_t prot)
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{
	pte_t *pte;
	unsigned long addr;

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	addr = start;
	do {
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		pte = pte_offset_kernel(pmd, addr);
		kvm_set_pte(pte, pfn_pte(pfn, prot));
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		get_page(virt_to_page(pte));
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		kvm_flush_dcache_to_poc(pte, sizeof(*pte));
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		pfn++;
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	} while (addr += PAGE_SIZE, addr != end);
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}

static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
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				   unsigned long end, unsigned long pfn,
				   pgprot_t prot)
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{
	pmd_t *pmd;
	pte_t *pte;
	unsigned long addr, next;

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	addr = start;
	do {
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		pmd = pmd_offset(pud, addr);
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		BUG_ON(pmd_sect(*pmd));

		if (pmd_none(*pmd)) {
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			pte = pte_alloc_one_kernel(NULL, addr);
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			if (!pte) {
				kvm_err("Cannot allocate Hyp pte\n");
				return -ENOMEM;
			}
			pmd_populate_kernel(NULL, pmd, pte);
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			get_page(virt_to_page(pmd));
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			kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
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		}

		next = pmd_addr_end(addr, end);

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		create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
		pfn += (next - addr) >> PAGE_SHIFT;
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	} while (addr = next, addr != end);
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	return 0;
}

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static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
				   unsigned long end, unsigned long pfn,
				   pgprot_t prot)
{
	pud_t *pud;
	pmd_t *pmd;
	unsigned long addr, next;
	int ret;

	addr = start;
	do {
		pud = pud_offset(pgd, addr);

		if (pud_none_or_clear_bad(pud)) {
			pmd = pmd_alloc_one(NULL, addr);
			if (!pmd) {
				kvm_err("Cannot allocate Hyp pmd\n");
				return -ENOMEM;
			}
			pud_populate(NULL, pud, pmd);
			get_page(virt_to_page(pud));
			kvm_flush_dcache_to_poc(pud, sizeof(*pud));
		}

		next = pud_addr_end(addr, end);
		ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
		if (ret)
			return ret;
		pfn += (next - addr) >> PAGE_SHIFT;
	} while (addr = next, addr != end);

	return 0;
}

626 627 628
static int __create_hyp_mappings(pgd_t *pgdp,
				 unsigned long start, unsigned long end,
				 unsigned long pfn, pgprot_t prot)
629 630 631 632 633 634 635
{
	pgd_t *pgd;
	pud_t *pud;
	unsigned long addr, next;
	int err = 0;

	mutex_lock(&kvm_hyp_pgd_mutex);
636 637 638
	addr = start & PAGE_MASK;
	end = PAGE_ALIGN(end);
	do {
639
		pgd = pgdp + pgd_index(addr);
640

641 642 643 644
		if (pgd_none(*pgd)) {
			pud = pud_alloc_one(NULL, addr);
			if (!pud) {
				kvm_err("Cannot allocate Hyp pud\n");
645 646 647
				err = -ENOMEM;
				goto out;
			}
648 649 650
			pgd_populate(NULL, pgd, pud);
			get_page(virt_to_page(pgd));
			kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
651 652 653
		}

		next = pgd_addr_end(addr, end);
654
		err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
655 656
		if (err)
			goto out;
657
		pfn += (next - addr) >> PAGE_SHIFT;
658
	} while (addr = next, addr != end);
659 660 661 662 663
out:
	mutex_unlock(&kvm_hyp_pgd_mutex);
	return err;
}

664 665 666 667 668 669 670 671 672 673 674
static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
{
	if (!is_vmalloc_addr(kaddr)) {
		BUG_ON(!virt_addr_valid(kaddr));
		return __pa(kaddr);
	} else {
		return page_to_phys(vmalloc_to_page(kaddr)) +
		       offset_in_page(kaddr);
	}
}

675
/**
676
 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
677 678
 * @from:	The virtual kernel start address of the range
 * @to:		The virtual kernel end address of the range (exclusive)
679
 * @prot:	The protection to be applied to this range
680
 *
681 682 683
 * The same virtual address as the kernel virtual address is also used
 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
 * physical pages.
684
 */
685
int create_hyp_mappings(void *from, void *to, pgprot_t prot)
686
{
687 688
	phys_addr_t phys_addr;
	unsigned long virt_addr;
M
Marc Zyngier 已提交
689 690
	unsigned long start = kern_hyp_va((unsigned long)from);
	unsigned long end = kern_hyp_va((unsigned long)to);
691

692 693 694
	if (is_kernel_in_hyp_mode())
		return 0;

695 696
	start = start & PAGE_MASK;
	end = PAGE_ALIGN(end);
697

698 699
	for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
		int err;
700

701 702 703 704
		phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
		err = __create_hyp_mappings(hyp_pgd, virt_addr,
					    virt_addr + PAGE_SIZE,
					    __phys_to_pfn(phys_addr),
705
					    prot);
706 707 708 709 710
		if (err)
			return err;
	}

	return 0;
711 712 713
}

/**
714 715 716
 * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
 * @from:	The kernel start VA of the range
 * @to:		The kernel end VA of the range (exclusive)
717
 * @phys_addr:	The physical start address which gets mapped
718 719 720
 *
 * The resulting HYP VA is the same as the kernel VA, modulo
 * HYP_PAGE_OFFSET.
721
 */
722
int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
723
{
M
Marc Zyngier 已提交
724 725
	unsigned long start = kern_hyp_va((unsigned long)from);
	unsigned long end = kern_hyp_va((unsigned long)to);
726

727 728 729
	if (is_kernel_in_hyp_mode())
		return 0;

730 731 732 733 734 735
	/* Check for a valid kernel IO mapping */
	if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
		return -EINVAL;

	return __create_hyp_mappings(hyp_pgd, start, end,
				     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
736 737
}

738 739 740 741
/**
 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
 * @kvm:	The KVM struct pointer for the VM.
 *
742 743 744
 * Allocates only the stage-2 HW PGD level table(s) (can support either full
 * 40-bit input addresses or limited to 32-bit input addresses). Clears the
 * allocated pages.
745 746 747 748 749 750 751 752 753 754 755 756 757
 *
 * Note we don't need locking here as this is only called when the VM is
 * created, which can only be done once.
 */
int kvm_alloc_stage2_pgd(struct kvm *kvm)
{
	pgd_t *pgd;

	if (kvm->arch.pgd != NULL) {
		kvm_err("kvm_arch already initialized?\n");
		return -EINVAL;
	}

758 759 760
	/* Allocate the HW PGD, making sure that each page gets its own refcount */
	pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
	if (!pgd)
761 762
		return -ENOMEM;

763 764 765 766
	kvm->arch.pgd = pgd;
	return 0;
}

767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
static void stage2_unmap_memslot(struct kvm *kvm,
				 struct kvm_memory_slot *memslot)
{
	hva_t hva = memslot->userspace_addr;
	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
	phys_addr_t size = PAGE_SIZE * memslot->npages;
	hva_t reg_end = hva + size;

	/*
	 * A memory region could potentially cover multiple VMAs, and any holes
	 * between them, so iterate over all of them to find out if we should
	 * unmap any of them.
	 *
	 *     +--------------------------------------------+
	 * +---------------+----------------+   +----------------+
	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
	 * +---------------+----------------+   +----------------+
	 *     |               memory region                |
	 *     +--------------------------------------------+
	 */
	do {
		struct vm_area_struct *vma = find_vma(current->mm, hva);
		hva_t vm_start, vm_end;

		if (!vma || vma->vm_start >= reg_end)
			break;

		/*
		 * Take the intersection of this VMA with the memory region
		 */
		vm_start = max(hva, vma->vm_start);
		vm_end = min(reg_end, vma->vm_end);

		if (!(vma->vm_flags & VM_PFNMAP)) {
			gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
			unmap_stage2_range(kvm, gpa, vm_end - vm_start);
		}
		hva = vm_end;
	} while (hva < reg_end);
}

/**
 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
 * @kvm: The struct kvm pointer
 *
 * Go through the memregions and unmap any reguler RAM
 * backing memory already mapped to the VM.
 */
void stage2_unmap_vm(struct kvm *kvm)
{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;
	int idx;

	idx = srcu_read_lock(&kvm->srcu);
822
	down_read(&current->mm->mmap_sem);
823 824 825 826 827 828 829
	spin_lock(&kvm->mmu_lock);

	slots = kvm_memslots(kvm);
	kvm_for_each_memslot(memslot, slots)
		stage2_unmap_memslot(kvm, memslot);

	spin_unlock(&kvm->mmu_lock);
830
	up_read(&current->mm->mmap_sem);
831 832 833
	srcu_read_unlock(&kvm->srcu, idx);
}

834 835 836 837 838 839 840 841 842 843
/**
 * kvm_free_stage2_pgd - free all stage-2 tables
 * @kvm:	The KVM struct pointer for the VM.
 *
 * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
 * underlying level-2 and level-3 tables before freeing the actual level-1 table
 * and setting the struct pointer to NULL.
 */
void kvm_free_stage2_pgd(struct kvm *kvm)
{
844
	void *pgd = NULL;
845

846
	spin_lock(&kvm->mmu_lock);
847 848
	if (kvm->arch.pgd) {
		unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
849
		pgd = READ_ONCE(kvm->arch.pgd);
850 851
		kvm->arch.pgd = NULL;
	}
852 853
	spin_unlock(&kvm->mmu_lock);

854
	/* Free the HW pgd, one page at a time */
855 856
	if (pgd)
		free_pages_exact(pgd, S2_PGD_SIZE);
857 858
}

859
static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
860
			     phys_addr_t addr)
861 862 863 864
{
	pgd_t *pgd;
	pud_t *pud;

865 866
	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
	if (WARN_ON(stage2_pgd_none(*pgd))) {
867 868 869
		if (!cache)
			return NULL;
		pud = mmu_memory_cache_alloc(cache);
870
		stage2_pgd_populate(pgd, pud);
871 872 873
		get_page(virt_to_page(pgd));
	}

874
	return stage2_pud_offset(pgd, addr);
875 876 877 878 879 880 881 882 883
}

static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			     phys_addr_t addr)
{
	pud_t *pud;
	pmd_t *pmd;

	pud = stage2_get_pud(kvm, cache, addr);
884 885 886
	if (!pud)
		return NULL;

887
	if (stage2_pud_none(*pud)) {
888
		if (!cache)
889
			return NULL;
890
		pmd = mmu_memory_cache_alloc(cache);
891
		stage2_pud_populate(pud, pmd);
892
		get_page(virt_to_page(pud));
893 894
	}

895
	return stage2_pmd_offset(pud, addr);
896 897 898 899 900 901 902 903 904
}

static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
			       *cache, phys_addr_t addr, const pmd_t *new_pmd)
{
	pmd_t *pmd, old_pmd;

	pmd = stage2_get_pmd(kvm, cache, addr);
	VM_BUG_ON(!pmd);
905

906 907 908 909 910 911 912 913 914 915 916 917
	/*
	 * Mapping in huge pages should only happen through a fault.  If a
	 * page is merged into a transparent huge page, the individual
	 * subpages of that huge page should be unmapped through MMU
	 * notifiers before we get here.
	 *
	 * Merging of CompoundPages is not supported; they should become
	 * splitting first, unmapped, merged, and mapped back in on-demand.
	 */
	VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));

	old_pmd = *pmd;
918 919
	if (pmd_present(old_pmd)) {
		pmd_clear(pmd);
920
		kvm_tlb_flush_vmid_ipa(kvm, addr);
921
	} else {
922
		get_page(virt_to_page(pmd));
923 924 925
	}

	kvm_set_pmd(pmd, *new_pmd);
926 927 928 929
	return 0;
}

static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
930 931
			  phys_addr_t addr, const pte_t *new_pte,
			  unsigned long flags)
932 933 934
{
	pmd_t *pmd;
	pte_t *pte, old_pte;
935 936 937 938
	bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
	bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;

	VM_BUG_ON(logging_active && !cache);
939

940
	/* Create stage-2 page table mapping - Levels 0 and 1 */
941 942 943 944 945 946 947 948 949
	pmd = stage2_get_pmd(kvm, cache, addr);
	if (!pmd) {
		/*
		 * Ignore calls from kvm_set_spte_hva for unallocated
		 * address ranges.
		 */
		return 0;
	}

950 951 952 953 954 955 956
	/*
	 * While dirty page logging - dissolve huge PMD, then continue on to
	 * allocate page.
	 */
	if (logging_active)
		stage2_dissolve_pmd(kvm, addr, pmd);

957
	/* Create stage-2 page mappings - Level 2 */
958 959 960 961 962 963
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
964 965 966
	}

	pte = pte_offset_kernel(pmd, addr);
967 968 969 970 971 972

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
973 974
	if (pte_present(old_pte)) {
		kvm_set_pte(pte, __pte(0));
975
		kvm_tlb_flush_vmid_ipa(kvm, addr);
976
	} else {
977
		get_page(virt_to_page(pte));
978
	}
979

980
	kvm_set_pte(pte, *new_pte);
981 982 983
	return 0;
}

984 985 986 987 988 989 990
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static int stage2_ptep_test_and_clear_young(pte_t *pte)
{
	if (pte_young(*pte)) {
		*pte = pte_mkold(*pte);
		return 1;
	}
991 992
	return 0;
}
993 994 995 996 997 998 999 1000 1001 1002 1003
#else
static int stage2_ptep_test_and_clear_young(pte_t *pte)
{
	return __ptep_test_and_clear_young(pte);
}
#endif

static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
{
	return stage2_ptep_test_and_clear_young((pte_t *)pmd);
}
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013

/**
 * kvm_phys_addr_ioremap - map a device range to guest IPA
 *
 * @kvm:	The KVM pointer
 * @guest_ipa:	The IPA at which to insert the mapping
 * @pa:		The physical address of the device
 * @size:	The size of the mapping
 */
int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1014
			  phys_addr_t pa, unsigned long size, bool writable)
1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
{
	phys_addr_t addr, end;
	int ret = 0;
	unsigned long pfn;
	struct kvm_mmu_memory_cache cache = { 0, };

	end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
	pfn = __phys_to_pfn(pa);

	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
1025
		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1026

1027
		if (writable)
1028
			pte = kvm_s2pte_mkwrite(pte);
1029

1030 1031
		ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
						KVM_NR_MEM_OBJS);
1032 1033 1034
		if (ret)
			goto out;
		spin_lock(&kvm->mmu_lock);
1035 1036
		ret = stage2_set_pte(kvm, &cache, addr, &pte,
						KVM_S2PTE_FLAG_IS_IOMAP);
1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
		spin_unlock(&kvm->mmu_lock);
		if (ret)
			goto out;

		pfn++;
	}

out:
	mmu_free_memory_cache(&cache);
	return ret;
}

D
Dan Williams 已提交
1049
static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1050
{
D
Dan Williams 已提交
1051
	kvm_pfn_t pfn = *pfnp;
1052 1053
	gfn_t gfn = *ipap >> PAGE_SHIFT;

1054
	if (PageTransCompoundMap(pfn_to_page(pfn))) {
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
		unsigned long mask;
		/*
		 * The address we faulted on is backed by a transparent huge
		 * page.  However, because we map the compound huge page and
		 * not the individual tail page, we need to transfer the
		 * refcount to the head page.  We have to be careful that the
		 * THP doesn't start to split while we are adjusting the
		 * refcounts.
		 *
		 * We are sure this doesn't happen, because mmu_notifier_retry
		 * was successful and we are holding the mmu_lock, so if this
		 * THP is trying to split, it will be blocked in the mmu
		 * notifier before touching any of the pages, specifically
		 * before being able to call __split_huge_page_refcount().
		 *
		 * We can therefore safely transfer the refcount from PG_tail
		 * to PG_head and switch the pfn from a tail page to the head
		 * page accordingly.
		 */
		mask = PTRS_PER_PMD - 1;
		VM_BUG_ON((gfn & mask) != (pfn & mask));
		if (pfn & mask) {
			*ipap &= PMD_MASK;
			kvm_release_pfn_clean(pfn);
			pfn &= ~mask;
			kvm_get_pfn(pfn);
			*pfnp = pfn;
		}

		return true;
	}

	return false;
}

1090 1091 1092 1093 1094 1095 1096 1097
static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
	if (kvm_vcpu_trap_is_iabt(vcpu))
		return false;

	return kvm_vcpu_dabt_iswrite(vcpu);
}

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
/**
 * stage2_wp_ptes - write protect PMD range
 * @pmd:	pointer to pmd entry
 * @addr:	range start address
 * @end:	range end address
 */
static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
			if (!kvm_s2pte_readonly(pte))
				kvm_set_s2pte_readonly(pte);
		}
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

/**
 * stage2_wp_pmds - write protect PUD range
 * @pud:	pointer to pud entry
 * @addr:	range start address
 * @end:	range end address
 */
static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
{
	pmd_t *pmd;
	phys_addr_t next;

1128
	pmd = stage2_pmd_offset(pud, addr);
1129 1130

	do {
1131
		next = stage2_pmd_addr_end(addr, end);
1132
		if (!pmd_none(*pmd)) {
1133
			if (pmd_thp_or_huge(*pmd)) {
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
				if (!kvm_s2pmd_readonly(pmd))
					kvm_set_s2pmd_readonly(pmd);
			} else {
				stage2_wp_ptes(pmd, addr, next);
			}
		}
	} while (pmd++, addr = next, addr != end);
}

/**
  * stage2_wp_puds - write protect PGD range
  * @pgd:	pointer to pgd entry
  * @addr:	range start address
  * @end:	range end address
  *
  * Process PUD entries, for a huge PUD we cause a panic.
  */
static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
{
	pud_t *pud;
	phys_addr_t next;

1156
	pud = stage2_pud_offset(pgd, addr);
1157
	do {
1158 1159
		next = stage2_pud_addr_end(addr, end);
		if (!stage2_pud_none(*pud)) {
1160
			/* TODO:PUD not supported, revisit later if supported */
1161
			BUG_ON(stage2_pud_huge(*pud));
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
			stage2_wp_pmds(pud, addr, next);
		}
	} while (pud++, addr = next, addr != end);
}

/**
 * stage2_wp_range() - write protect stage2 memory region range
 * @kvm:	The KVM pointer
 * @addr:	Start address of range
 * @end:	End address of range
 */
static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
{
	pgd_t *pgd;
	phys_addr_t next;

1178
	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1179 1180 1181 1182
	do {
		/*
		 * Release kvm_mmu_lock periodically if the memory region is
		 * large. Otherwise, we may see kernel panics with
1183 1184
		 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
		 * CONFIG_LOCKDEP. Additionally, holding the lock too long
1185 1186 1187
		 * will also starve other vCPUs. We have to also make sure
		 * that the page tables are not freed while we released
		 * the lock.
1188
		 */
1189 1190 1191
		cond_resched_lock(&kvm->mmu_lock);
		if (!READ_ONCE(kvm->arch.pgd))
			break;
1192 1193
		next = stage2_pgd_addr_end(addr, end);
		if (stage2_pgd_present(*pgd))
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
			stage2_wp_puds(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

/**
 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
 * @kvm:	The KVM pointer
 * @slot:	The memory slot to write protect
 *
 * Called to start logging dirty pages after memory region
 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
 * all present PMD and PTEs are write protected in the memory region.
 * Afterwards read of dirty page log can be called.
 *
 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
 * serializing operations for VM memory regions.
 */
void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
{
1213 1214
	struct kvm_memslots *slots = kvm_memslots(kvm);
	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1215 1216 1217 1218 1219 1220 1221 1222
	phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
	phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;

	spin_lock(&kvm->mmu_lock);
	stage2_wp_range(kvm, start, end);
	spin_unlock(&kvm->mmu_lock);
	kvm_flush_remote_tlbs(kvm);
}
1223 1224

/**
1225
 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1226 1227 1228 1229 1230 1231 1232 1233 1234
 * @kvm:	The KVM pointer
 * @slot:	The memory slot associated with mask
 * @gfn_offset:	The gfn offset in memory slot
 * @mask:	The mask of dirty pages at offset 'gfn_offset' in this memory
 *		slot to be write protected
 *
 * Walks bits set in mask write protects the associated pte's. Caller must
 * acquire kvm_mmu_lock.
 */
1235
static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1236 1237 1238 1239 1240 1241 1242 1243 1244
		struct kvm_memory_slot *slot,
		gfn_t gfn_offset, unsigned long mask)
{
	phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
	phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
	phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;

	stage2_wp_range(kvm, start, end);
}
1245

1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
/*
 * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
 * dirty pages.
 *
 * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
 * enable dirty logging for them.
 */
void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
		struct kvm_memory_slot *slot,
		gfn_t gfn_offset, unsigned long mask)
{
	kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
}

D
Dan Williams 已提交
1260
static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1261
				      unsigned long size)
1262
{
1263
	__coherent_cache_guest_page(vcpu, pfn, size);
1264 1265
}

1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
static void kvm_send_hwpoison_signal(unsigned long address,
				     struct vm_area_struct *vma)
{
	siginfo_t info;

	info.si_signo   = SIGBUS;
	info.si_errno   = 0;
	info.si_code    = BUS_MCEERR_AR;
	info.si_addr    = (void __user *)address;

	if (is_vm_hugetlb_page(vma))
		info.si_addr_lsb = huge_page_shift(hstate_vma(vma));
	else
		info.si_addr_lsb = PAGE_SHIFT;

	send_sig_info(SIGBUS, &info, current);
}

1284
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1285
			  struct kvm_memory_slot *memslot, unsigned long hva,
1286 1287 1288
			  unsigned long fault_status)
{
	int ret;
1289
	bool write_fault, writable, hugetlb = false, force_pte = false;
1290
	unsigned long mmu_seq;
1291 1292
	gfn_t gfn = fault_ipa >> PAGE_SHIFT;
	struct kvm *kvm = vcpu->kvm;
1293
	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1294
	struct vm_area_struct *vma;
D
Dan Williams 已提交
1295
	kvm_pfn_t pfn;
1296
	pgprot_t mem_type = PAGE_S2;
1297 1298
	bool logging_active = memslot_is_logging(memslot);
	unsigned long flags = 0;
1299

1300
	write_fault = kvm_is_write_fault(vcpu);
1301 1302 1303 1304 1305
	if (fault_status == FSC_PERM && !write_fault) {
		kvm_err("Unexpected L2 read permission error\n");
		return -EFAULT;
	}

1306 1307 1308
	/* Let's check if we will get back a huge page backed by hugetlbfs */
	down_read(&current->mm->mmap_sem);
	vma = find_vma_intersection(current->mm, hva, hva + 1);
1309 1310 1311 1312 1313 1314
	if (unlikely(!vma)) {
		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
		up_read(&current->mm->mmap_sem);
		return -EFAULT;
	}

1315
	if (is_vm_hugetlb_page(vma) && !logging_active) {
1316 1317
		hugetlb = true;
		gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1318 1319
	} else {
		/*
1320 1321 1322 1323 1324 1325 1326
		 * Pages belonging to memslots that don't have the same
		 * alignment for userspace and IPA cannot be mapped using
		 * block descriptors even if the pages belong to a THP for
		 * the process, because the stage-2 block descriptor will
		 * cover more than a single THP and we loose atomicity for
		 * unmapping, updates, and splits of the THP or other pages
		 * in the stage-2 block range.
1327
		 */
1328 1329
		if ((memslot->userspace_addr & ~PMD_MASK) !=
		    ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1330
			force_pte = true;
1331 1332 1333
	}
	up_read(&current->mm->mmap_sem);

1334
	/* We need minimum second+third level pages */
1335 1336
	ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
				     KVM_NR_MEM_OBJS);
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
	if (ret)
		return ret;

	mmu_seq = vcpu->kvm->mmu_notifier_seq;
	/*
	 * Ensure the read of mmu_notifier_seq happens before we call
	 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
	 * the page we just got a reference to gets unmapped before we have a
	 * chance to grab the mmu_lock, which ensure that if the page gets
	 * unmapped afterwards, the call to kvm_unmap_hva will take it away
	 * from us again properly. This smp_rmb() interacts with the smp_wmb()
	 * in kvm_mmu_notifier_invalidate_<page|range_end>.
	 */
	smp_rmb();

1352
	pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1353 1354 1355 1356
	if (pfn == KVM_PFN_ERR_HWPOISON) {
		kvm_send_hwpoison_signal(hva, vma);
		return 0;
	}
1357
	if (is_error_noslot_pfn(pfn))
1358 1359
		return -EFAULT;

1360
	if (kvm_is_device_pfn(pfn)) {
1361
		mem_type = PAGE_S2_DEVICE;
1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
		flags |= KVM_S2PTE_FLAG_IS_IOMAP;
	} else if (logging_active) {
		/*
		 * Faults on pages in a memslot with logging enabled
		 * should not be mapped with huge pages (it introduces churn
		 * and performance degradation), so force a pte mapping.
		 */
		force_pte = true;
		flags |= KVM_S2_FLAG_LOGGING_ACTIVE;

		/*
		 * Only actually map the page as writable if this was a write
		 * fault.
		 */
		if (!write_fault)
			writable = false;
	}
1379

1380 1381
	spin_lock(&kvm->mmu_lock);
	if (mmu_notifier_retry(kvm, mmu_seq))
1382
		goto out_unlock;
1383

1384 1385
	if (!hugetlb && !force_pte)
		hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1386 1387

	if (hugetlb) {
1388
		pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1389 1390
		new_pmd = pmd_mkhuge(new_pmd);
		if (writable) {
1391
			new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1392 1393
			kvm_set_pfn_dirty(pfn);
		}
1394
		coherent_cache_guest_page(vcpu, pfn, PMD_SIZE);
1395 1396
		ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
	} else {
1397
		pte_t new_pte = pfn_pte(pfn, mem_type);
1398

1399
		if (writable) {
1400
			new_pte = kvm_s2pte_mkwrite(new_pte);
1401
			kvm_set_pfn_dirty(pfn);
1402
			mark_page_dirty(kvm, gfn);
1403
		}
1404
		coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE);
1405
		ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1406
	}
1407

1408
out_unlock:
1409
	spin_unlock(&kvm->mmu_lock);
1410
	kvm_set_pfn_accessed(pfn);
1411
	kvm_release_pfn_clean(pfn);
1412
	return ret;
1413 1414
}

1415 1416 1417 1418
/*
 * Resolve the access fault by making the page young again.
 * Note that because the faulting entry is guaranteed not to be
 * cached in the TLB, we don't need to invalidate anything.
1419 1420
 * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
 * so there is no need for atomic (pte|pmd)_mkyoung operations.
1421 1422 1423 1424 1425
 */
static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
{
	pmd_t *pmd;
	pte_t *pte;
D
Dan Williams 已提交
1426
	kvm_pfn_t pfn;
1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
	bool pfn_valid = false;

	trace_kvm_access_fault(fault_ipa);

	spin_lock(&vcpu->kvm->mmu_lock);

	pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
	if (!pmd || pmd_none(*pmd))	/* Nothing there */
		goto out;

1437
	if (pmd_thp_or_huge(*pmd)) {	/* THP, HugeTLB */
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
		*pmd = pmd_mkyoung(*pmd);
		pfn = pmd_pfn(*pmd);
		pfn_valid = true;
		goto out;
	}

	pte = pte_offset_kernel(pmd, fault_ipa);
	if (pte_none(*pte))		/* Nothing there either */
		goto out;

	*pte = pte_mkyoung(*pte);	/* Just a page... */
	pfn = pte_pfn(*pte);
	pfn_valid = true;
out:
	spin_unlock(&vcpu->kvm->mmu_lock);
	if (pfn_valid)
		kvm_set_pfn_accessed(pfn);
}

1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
static bool is_abort_sea(unsigned long fault_status)
{
	switch (fault_status) {
	case FSC_SEA:
	case FSC_SEA_TTW0:
	case FSC_SEA_TTW1:
	case FSC_SEA_TTW2:
	case FSC_SEA_TTW3:
	case FSC_SECC:
	case FSC_SECC_TTW0:
	case FSC_SECC_TTW1:
	case FSC_SECC_TTW2:
	case FSC_SECC_TTW3:
		return true;
	default:
		return false;
	}
}

1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487
/**
 * kvm_handle_guest_abort - handles all 2nd stage aborts
 * @vcpu:	the VCPU pointer
 * @run:	the kvm_run structure
 *
 * Any abort that gets to the host is almost guaranteed to be caused by a
 * missing second stage translation table entry, which can mean that either the
 * guest simply needs more memory and we must allocate an appropriate page or it
 * can mean that the guest tried to access I/O memory, which is emulated by user
 * space. The distinction is based on the IPA causing the fault and whether this
 * memory region has been registered as standard RAM by user space.
 */
1488 1489
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
1490 1491 1492
	unsigned long fault_status;
	phys_addr_t fault_ipa;
	struct kvm_memory_slot *memslot;
1493 1494
	unsigned long hva;
	bool is_iabt, write_fault, writable;
1495 1496 1497
	gfn_t gfn;
	int ret, idx;

1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);

	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);

	/*
	 * The host kernel will handle the synchronous external abort. There
	 * is no need to pass the error into the guest.
	 */
	if (is_abort_sea(fault_status)) {
		if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu)))
			return 1;
	}

1511
	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1512 1513 1514 1515 1516
	if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
		kvm_inject_vabt(vcpu);
		return 1;
	}

1517 1518
	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
1519 1520

	/* Check the stage-2 fault is trans. fault or write fault */
1521 1522
	if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
	    fault_status != FSC_ACCESS) {
1523 1524 1525 1526
		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
			kvm_vcpu_trap_get_class(vcpu),
			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
			(unsigned long)kvm_vcpu_get_hsr(vcpu));
1527 1528 1529 1530 1531 1532
		return -EFAULT;
	}

	idx = srcu_read_lock(&vcpu->kvm->srcu);

	gfn = fault_ipa >> PAGE_SHIFT;
1533 1534
	memslot = gfn_to_memslot(vcpu->kvm, gfn);
	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1535
	write_fault = kvm_is_write_fault(vcpu);
1536
	if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1537 1538
		if (is_iabt) {
			/* Prefetch Abort on I/O address */
1539
			kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1540 1541 1542 1543
			ret = 1;
			goto out_unlock;
		}

1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
		/*
		 * Check for a cache maintenance operation. Since we
		 * ended-up here, we know it is outside of any memory
		 * slot. But we can't find out if that is for a device,
		 * or if the guest is just being stupid. The only thing
		 * we know for sure is that this range cannot be cached.
		 *
		 * So let's assume that the guest is just being
		 * cautious, and skip the instruction.
		 */
		if (kvm_vcpu_dabt_is_cm(vcpu)) {
			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
			ret = 1;
			goto out_unlock;
		}

M
Marc Zyngier 已提交
1560 1561 1562 1563 1564 1565 1566
		/*
		 * The IPA is reported as [MAX:12], so we need to
		 * complement it with the bottom 12 bits from the
		 * faulting VA. This is always 12 bits, irrespective
		 * of the page size.
		 */
		fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
C
Christoffer Dall 已提交
1567
		ret = io_mem_abort(vcpu, run, fault_ipa);
1568 1569 1570
		goto out_unlock;
	}

1571 1572 1573
	/* Userspace should not be able to register out-of-bounds IPAs */
	VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);

1574 1575 1576 1577 1578 1579
	if (fault_status == FSC_ACCESS) {
		handle_access_fault(vcpu, fault_ipa);
		ret = 1;
		goto out_unlock;
	}

1580
	ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1581 1582 1583 1584 1585
	if (ret == 0)
		ret = 1;
out_unlock:
	srcu_read_unlock(&vcpu->kvm->srcu, idx);
	return ret;
1586 1587
}

1588 1589 1590 1591
static int handle_hva_to_gpa(struct kvm *kvm,
			     unsigned long start,
			     unsigned long end,
			     int (*handler)(struct kvm *kvm,
1592 1593
					    gpa_t gpa, u64 size,
					    void *data),
1594
			     void *data)
1595 1596 1597
{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;
1598
	int ret = 0;
1599 1600 1601 1602 1603 1604

	slots = kvm_memslots(kvm);

	/* we only care about the pages that the guest sees */
	kvm_for_each_memslot(memslot, slots) {
		unsigned long hva_start, hva_end;
1605
		gfn_t gpa;
1606 1607 1608 1609 1610 1611 1612

		hva_start = max(start, memslot->userspace_addr);
		hva_end = min(end, memslot->userspace_addr +
					(memslot->npages << PAGE_SHIFT));
		if (hva_start >= hva_end)
			continue;

1613 1614
		gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT;
		ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data);
1615
	}
1616 1617

	return ret;
1618 1619
}

1620
static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1621
{
1622
	unmap_stage2_range(kvm, gpa, size);
1623
	return 0;
1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
}

int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
{
	unsigned long end = hva + PAGE_SIZE;

	if (!kvm->arch.pgd)
		return 0;

	trace_kvm_unmap_hva(hva);
	handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
	return 0;
}

int kvm_unmap_hva_range(struct kvm *kvm,
			unsigned long start, unsigned long end)
{
	if (!kvm->arch.pgd)
		return 0;

	trace_kvm_unmap_hva_range(start, end);
	handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
	return 0;
}

1649
static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1650 1651 1652
{
	pte_t *pte = (pte_t *)data;

1653
	WARN_ON(size != PAGE_SIZE);
1654 1655 1656 1657 1658 1659 1660 1661
	/*
	 * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
	 * flag clear because MMU notifiers will have unmapped a huge PMD before
	 * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
	 * therefore stage2_set_pte() never needs to clear out a huge PMD
	 * through this calling path.
	 */
	stage2_set_pte(kvm, NULL, gpa, pte, 0);
1662
	return 0;
1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678
}


void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
	unsigned long end = hva + PAGE_SIZE;
	pte_t stage2_pte;

	if (!kvm->arch.pgd)
		return;

	trace_kvm_set_spte_hva(hva);
	stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
	handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
}

1679
static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1680 1681 1682 1683
{
	pmd_t *pmd;
	pte_t *pte;

1684
	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1685 1686 1687 1688
	pmd = stage2_get_pmd(kvm, NULL, gpa);
	if (!pmd || pmd_none(*pmd))	/* Nothing there */
		return 0;

1689 1690
	if (pmd_thp_or_huge(*pmd))	/* THP, HugeTLB */
		return stage2_pmdp_test_and_clear_young(pmd);
1691 1692 1693 1694 1695

	pte = pte_offset_kernel(pmd, gpa);
	if (pte_none(*pte))
		return 0;

1696
	return stage2_ptep_test_and_clear_young(pte);
1697 1698
}

1699
static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1700 1701 1702 1703
{
	pmd_t *pmd;
	pte_t *pte;

1704
	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1705 1706 1707 1708
	pmd = stage2_get_pmd(kvm, NULL, gpa);
	if (!pmd || pmd_none(*pmd))	/* Nothing there */
		return 0;

1709
	if (pmd_thp_or_huge(*pmd))		/* THP, HugeTLB */
1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720
		return pmd_young(*pmd);

	pte = pte_offset_kernel(pmd, gpa);
	if (!pte_none(*pte))		/* Just a page... */
		return pte_young(*pte);

	return 0;
}

int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
{
1721 1722
	if (!kvm->arch.pgd)
		return 0;
1723 1724 1725 1726 1727 1728
	trace_kvm_age_hva(start, end);
	return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
}

int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
{
1729 1730
	if (!kvm->arch.pgd)
		return 0;
1731 1732 1733 1734
	trace_kvm_test_age_hva(hva);
	return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
}

1735 1736 1737 1738 1739
void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
{
	mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
}

1740 1741
phys_addr_t kvm_mmu_get_httbr(void)
{
1742 1743 1744 1745
	if (__kvm_cpu_uses_extended_idmap())
		return virt_to_phys(merged_hyp_pgd);
	else
		return virt_to_phys(hyp_pgd);
1746 1747
}

1748 1749 1750 1751 1752
phys_addr_t kvm_get_idmap_vector(void)
{
	return hyp_idmap_vector;
}

1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768
static int kvm_map_idmap_text(pgd_t *pgd)
{
	int err;

	/* Create the idmap in the boot page tables */
	err = 	__create_hyp_mappings(pgd,
				      hyp_idmap_start, hyp_idmap_end,
				      __phys_to_pfn(hyp_idmap_start),
				      PAGE_HYP_EXEC);
	if (err)
		kvm_err("Failed to idmap %lx-%lx\n",
			hyp_idmap_start, hyp_idmap_end);

	return err;
}

1769 1770
int kvm_mmu_init(void)
{
1771 1772
	int err;

1773 1774 1775
	hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
	hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
	hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1776

1777 1778 1779 1780 1781
	/*
	 * We rely on the linker script to ensure at build time that the HYP
	 * init code does not cross a page boundary.
	 */
	BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1782

1783 1784
	kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
	kvm_info("HYP VA range: %lx:%lx\n",
M
Marc Zyngier 已提交
1785
		 kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
1786

M
Marc Zyngier 已提交
1787
	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1788 1789
	    hyp_idmap_start <  kern_hyp_va(~0UL) &&
	    hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1790 1791 1792 1793 1794 1795 1796 1797 1798
		/*
		 * The idmap page is intersecting with the VA space,
		 * it is not safe to continue further.
		 */
		kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
		err = -EINVAL;
		goto out;
	}

1799
	hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1800
	if (!hyp_pgd) {
1801
		kvm_err("Hyp mode PGD not allocated\n");
1802 1803 1804 1805
		err = -ENOMEM;
		goto out;
	}

1806 1807 1808 1809 1810 1811 1812 1813
	if (__kvm_cpu_uses_extended_idmap()) {
		boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
							 hyp_pgd_order);
		if (!boot_hyp_pgd) {
			kvm_err("Hyp boot PGD not allocated\n");
			err = -ENOMEM;
			goto out;
		}
1814

1815 1816 1817
		err = kvm_map_idmap_text(boot_hyp_pgd);
		if (err)
			goto out;
1818

1819 1820 1821 1822 1823 1824 1825
		merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
		if (!merged_hyp_pgd) {
			kvm_err("Failed to allocate extra HYP pgd\n");
			goto out;
		}
		__kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
				    hyp_idmap_start);
1826 1827 1828 1829
	} else {
		err = kvm_map_idmap_text(hyp_pgd);
		if (err)
			goto out;
1830 1831
	}

1832
	return 0;
1833
out:
1834
	free_hyp_pgds();
1835
	return err;
1836
}
1837 1838

void kvm_arch_commit_memory_region(struct kvm *kvm,
1839
				   const struct kvm_userspace_memory_region *mem,
1840
				   const struct kvm_memory_slot *old,
1841
				   const struct kvm_memory_slot *new,
1842 1843
				   enum kvm_mr_change change)
{
1844 1845 1846 1847 1848 1849 1850
	/*
	 * At this point memslot has been committed and there is an
	 * allocated dirty_bitmap[], dirty pages will be be tracked while the
	 * memory slot is write protected.
	 */
	if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
		kvm_mmu_wp_memory_region(kvm, mem->slot);
1851 1852 1853 1854
}

int kvm_arch_prepare_memory_region(struct kvm *kvm,
				   struct kvm_memory_slot *memslot,
1855
				   const struct kvm_userspace_memory_region *mem,
1856 1857
				   enum kvm_mr_change change)
{
1858 1859 1860 1861 1862
	hva_t hva = mem->userspace_addr;
	hva_t reg_end = hva + mem->memory_size;
	bool writable = !(mem->flags & KVM_MEM_READONLY);
	int ret = 0;

1863 1864
	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
			change != KVM_MR_FLAGS_ONLY)
1865 1866
		return 0;

1867 1868 1869 1870 1871 1872 1873 1874
	/*
	 * Prevent userspace from creating a memory region outside of the IPA
	 * space addressable by the KVM guest IPA space.
	 */
	if (memslot->base_gfn + memslot->npages >=
	    (KVM_PHYS_SIZE >> PAGE_SHIFT))
		return -EFAULT;

1875
	down_read(&current->mm->mmap_sem);
1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
	/*
	 * A memory region could potentially cover multiple VMAs, and any holes
	 * between them, so iterate over all of them to find out if we can map
	 * any of them right now.
	 *
	 *     +--------------------------------------------+
	 * +---------------+----------------+   +----------------+
	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
	 * +---------------+----------------+   +----------------+
	 *     |               memory region                |
	 *     +--------------------------------------------+
	 */
	do {
		struct vm_area_struct *vma = find_vma(current->mm, hva);
		hva_t vm_start, vm_end;

		if (!vma || vma->vm_start >= reg_end)
			break;

		/*
		 * Mapping a read-only VMA is only allowed if the
		 * memory region is configured as read-only.
		 */
		if (writable && !(vma->vm_flags & VM_WRITE)) {
			ret = -EPERM;
			break;
		}

		/*
		 * Take the intersection of this VMA with the memory region
		 */
		vm_start = max(hva, vma->vm_start);
		vm_end = min(reg_end, vma->vm_end);

		if (vma->vm_flags & VM_PFNMAP) {
			gpa_t gpa = mem->guest_phys_addr +
				    (vm_start - mem->userspace_addr);
1913 1914 1915 1916
			phys_addr_t pa;

			pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
			pa += vm_start - vma->vm_start;
1917

1918
			/* IO region dirty page logging not allowed */
1919 1920 1921 1922
			if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
				ret = -EINVAL;
				goto out;
			}
1923

1924 1925 1926 1927 1928 1929 1930 1931 1932
			ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
						    vm_end - vm_start,
						    writable);
			if (ret)
				break;
		}
		hva = vm_end;
	} while (hva < reg_end);

1933
	if (change == KVM_MR_FLAGS_ONLY)
1934
		goto out;
1935

1936 1937
	spin_lock(&kvm->mmu_lock);
	if (ret)
1938
		unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1939 1940 1941
	else
		stage2_flush_memslot(kvm, memslot);
	spin_unlock(&kvm->mmu_lock);
1942 1943
out:
	up_read(&current->mm->mmap_sem);
1944
	return ret;
1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957
}

void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
			   struct kvm_memory_slot *dont)
{
}

int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
			    unsigned long npages)
{
	return 0;
}

1958
void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1959 1960 1961 1962 1963
{
}

void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
1964
	kvm_free_stage2_pgd(kvm);
1965 1966 1967 1968 1969
}

void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
				   struct kvm_memory_slot *slot)
{
1970 1971 1972 1973 1974 1975
	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
	phys_addr_t size = slot->npages << PAGE_SHIFT;

	spin_lock(&kvm->mmu_lock);
	unmap_stage2_range(kvm, gpa, size);
	spin_unlock(&kvm->mmu_lock);
1976
}
1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044

/*
 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
 *
 * Main problems:
 * - S/W ops are local to a CPU (not broadcast)
 * - We have line migration behind our back (speculation)
 * - System caches don't support S/W at all (damn!)
 *
 * In the face of the above, the best we can do is to try and convert
 * S/W ops to VA ops. Because the guest is not allowed to infer the
 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
 * which is a rather good thing for us.
 *
 * Also, it is only used when turning caches on/off ("The expected
 * usage of the cache maintenance instructions that operate by set/way
 * is associated with the cache maintenance instructions associated
 * with the powerdown and powerup of caches, if this is required by
 * the implementation.").
 *
 * We use the following policy:
 *
 * - If we trap a S/W operation, we enable VM trapping to detect
 *   caches being turned on/off, and do a full clean.
 *
 * - We flush the caches on both caches being turned on and off.
 *
 * - Once the caches are enabled, we stop trapping VM ops.
 */
void kvm_set_way_flush(struct kvm_vcpu *vcpu)
{
	unsigned long hcr = vcpu_get_hcr(vcpu);

	/*
	 * If this is the first time we do a S/W operation
	 * (i.e. HCR_TVM not set) flush the whole memory, and set the
	 * VM trapping.
	 *
	 * Otherwise, rely on the VM trapping to wait for the MMU +
	 * Caches to be turned off. At that point, we'll be able to
	 * clean the caches again.
	 */
	if (!(hcr & HCR_TVM)) {
		trace_kvm_set_way_flush(*vcpu_pc(vcpu),
					vcpu_has_cache_enabled(vcpu));
		stage2_flush_vm(vcpu->kvm);
		vcpu_set_hcr(vcpu, hcr | HCR_TVM);
	}
}

void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
{
	bool now_enabled = vcpu_has_cache_enabled(vcpu);

	/*
	 * If switching the MMU+caches on, need to invalidate the caches.
	 * If switching it off, need to clean the caches.
	 * Clean + invalidate does the trick always.
	 */
	if (now_enabled != was_enabled)
		stage2_flush_vm(vcpu->kvm);

	/* Caches are now on, stop trapping VM ops (until a S/W op) */
	if (now_enabled)
		vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);

	trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
}