mmu.c 51.5 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 <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 "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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		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;
}

617 618 619
static int __create_hyp_mappings(pgd_t *pgdp,
				 unsigned long start, unsigned long end,
				 unsigned long pfn, pgprot_t prot)
620 621 622 623 624 625 626
{
	pgd_t *pgd;
	pud_t *pud;
	unsigned long addr, next;
	int err = 0;

	mutex_lock(&kvm_hyp_pgd_mutex);
627 628 629
	addr = start & PAGE_MASK;
	end = PAGE_ALIGN(end);
	do {
630
		pgd = pgdp + pgd_index(addr);
631

632 633 634 635
		if (pgd_none(*pgd)) {
			pud = pud_alloc_one(NULL, addr);
			if (!pud) {
				kvm_err("Cannot allocate Hyp pud\n");
636 637 638
				err = -ENOMEM;
				goto out;
			}
639 640 641
			pgd_populate(NULL, pgd, pud);
			get_page(virt_to_page(pgd));
			kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
642 643 644
		}

		next = pgd_addr_end(addr, end);
645
		err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
646 647
		if (err)
			goto out;
648
		pfn += (next - addr) >> PAGE_SHIFT;
649
	} while (addr = next, addr != end);
650 651 652 653 654
out:
	mutex_unlock(&kvm_hyp_pgd_mutex);
	return err;
}

655 656 657 658 659 660 661 662 663 664 665
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);
	}
}

666
/**
667
 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
668 669
 * @from:	The virtual kernel start address of the range
 * @to:		The virtual kernel end address of the range (exclusive)
670
 * @prot:	The protection to be applied to this range
671
 *
672 673 674
 * 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.
675
 */
676
int create_hyp_mappings(void *from, void *to, pgprot_t prot)
677
{
678 679
	phys_addr_t phys_addr;
	unsigned long virt_addr;
M
Marc Zyngier 已提交
680 681
	unsigned long start = kern_hyp_va((unsigned long)from);
	unsigned long end = kern_hyp_va((unsigned long)to);
682

683 684 685
	if (is_kernel_in_hyp_mode())
		return 0;

686 687
	start = start & PAGE_MASK;
	end = PAGE_ALIGN(end);
688

689 690
	for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
		int err;
691

692 693 694 695
		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),
696
					    prot);
697 698 699 700 701
		if (err)
			return err;
	}

	return 0;
702 703 704
}

/**
705 706 707
 * 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)
708
 * @phys_addr:	The physical start address which gets mapped
709 710 711
 *
 * The resulting HYP VA is the same as the kernel VA, modulo
 * HYP_PAGE_OFFSET.
712
 */
713
int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
714
{
M
Marc Zyngier 已提交
715 716
	unsigned long start = kern_hyp_va((unsigned long)from);
	unsigned long end = kern_hyp_va((unsigned long)to);
717

718 719 720
	if (is_kernel_in_hyp_mode())
		return 0;

721 722 723 724 725 726
	/* 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);
727 728
}

729 730 731 732
/**
 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
 * @kvm:	The KVM struct pointer for the VM.
 *
733 734 735
 * 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.
736 737 738 739 740 741 742 743 744 745 746 747 748
 *
 * 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;
	}

749 750 751
	/* 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)
752 753
		return -ENOMEM;

754 755 756 757
	kvm->arch.pgd = pgd;
	return 0;
}

758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812
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);
813
	down_read(&current->mm->mmap_sem);
814 815 816 817 818 819 820
	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);
821
	up_read(&current->mm->mmap_sem);
822 823 824
	srcu_read_unlock(&kvm->srcu, idx);
}

825 826 827 828 829 830 831 832 833 834
/**
 * 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)
{
835
	void *pgd = NULL;
836

837
	spin_lock(&kvm->mmu_lock);
838 839
	if (kvm->arch.pgd) {
		unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
840
		pgd = READ_ONCE(kvm->arch.pgd);
841 842
		kvm->arch.pgd = NULL;
	}
843 844
	spin_unlock(&kvm->mmu_lock);

845
	/* Free the HW pgd, one page at a time */
846 847
	if (pgd)
		free_pages_exact(pgd, S2_PGD_SIZE);
848 849
}

850
static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
851
			     phys_addr_t addr)
852 853 854 855
{
	pgd_t *pgd;
	pud_t *pud;

856 857
	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
	if (WARN_ON(stage2_pgd_none(*pgd))) {
858 859 860
		if (!cache)
			return NULL;
		pud = mmu_memory_cache_alloc(cache);
861
		stage2_pgd_populate(pgd, pud);
862 863 864
		get_page(virt_to_page(pgd));
	}

865
	return stage2_pud_offset(pgd, addr);
866 867 868 869 870 871 872 873 874
}

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);
875
	if (stage2_pud_none(*pud)) {
876
		if (!cache)
877
			return NULL;
878
		pmd = mmu_memory_cache_alloc(cache);
879
		stage2_pud_populate(pud, pmd);
880
		get_page(virt_to_page(pud));
881 882
	}

883
	return stage2_pmd_offset(pud, addr);
884 885 886 887 888 889 890 891 892
}

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);
893

894 895 896 897 898 899 900 901 902 903 904 905
	/*
	 * 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;
906 907
	if (pmd_present(old_pmd)) {
		pmd_clear(pmd);
908
		kvm_tlb_flush_vmid_ipa(kvm, addr);
909
	} else {
910
		get_page(virt_to_page(pmd));
911 912 913
	}

	kvm_set_pmd(pmd, *new_pmd);
914 915 916 917
	return 0;
}

static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
918 919
			  phys_addr_t addr, const pte_t *new_pte,
			  unsigned long flags)
920 921 922
{
	pmd_t *pmd;
	pte_t *pte, old_pte;
923 924 925 926
	bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
	bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;

	VM_BUG_ON(logging_active && !cache);
927

928
	/* Create stage-2 page table mapping - Levels 0 and 1 */
929 930 931 932 933 934 935 936 937
	pmd = stage2_get_pmd(kvm, cache, addr);
	if (!pmd) {
		/*
		 * Ignore calls from kvm_set_spte_hva for unallocated
		 * address ranges.
		 */
		return 0;
	}

938 939 940 941 942 943 944
	/*
	 * While dirty page logging - dissolve huge PMD, then continue on to
	 * allocate page.
	 */
	if (logging_active)
		stage2_dissolve_pmd(kvm, addr, pmd);

945
	/* Create stage-2 page mappings - Level 2 */
946 947 948 949 950 951
	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));
952 953 954
	}

	pte = pte_offset_kernel(pmd, addr);
955 956 957 958 959 960

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

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
961 962
	if (pte_present(old_pte)) {
		kvm_set_pte(pte, __pte(0));
963
		kvm_tlb_flush_vmid_ipa(kvm, addr);
964
	} else {
965
		get_page(virt_to_page(pte));
966
	}
967

968
	kvm_set_pte(pte, *new_pte);
969 970 971
	return 0;
}

972 973 974 975 976 977 978
#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;
	}
979 980
	return 0;
}
981 982 983 984 985 986 987 988 989 990 991
#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);
}
992 993 994 995 996 997 998 999 1000 1001

/**
 * 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,
1002
			  phys_addr_t pa, unsigned long size, bool writable)
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
{
	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) {
1013
		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1014

1015
		if (writable)
1016
			pte = kvm_s2pte_mkwrite(pte);
1017

1018 1019
		ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
						KVM_NR_MEM_OBJS);
1020 1021 1022
		if (ret)
			goto out;
		spin_lock(&kvm->mmu_lock);
1023 1024
		ret = stage2_set_pte(kvm, &cache, addr, &pte,
						KVM_S2PTE_FLAG_IS_IOMAP);
1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
		spin_unlock(&kvm->mmu_lock);
		if (ret)
			goto out;

		pfn++;
	}

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

D
Dan Williams 已提交
1037
static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1038
{
D
Dan Williams 已提交
1039
	kvm_pfn_t pfn = *pfnp;
1040 1041
	gfn_t gfn = *ipap >> PAGE_SHIFT;

1042
	if (PageTransCompoundMap(pfn_to_page(pfn))) {
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
		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;
}

1078 1079 1080 1081 1082 1083 1084 1085
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);
}

1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
/**
 * 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;

1116
	pmd = stage2_pmd_offset(pud, addr);
1117 1118

	do {
1119
		next = stage2_pmd_addr_end(addr, end);
1120
		if (!pmd_none(*pmd)) {
1121
			if (pmd_thp_or_huge(*pmd)) {
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
				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;

1144
	pud = stage2_pud_offset(pgd, addr);
1145
	do {
1146 1147
		next = stage2_pud_addr_end(addr, end);
		if (!stage2_pud_none(*pud)) {
1148
			/* TODO:PUD not supported, revisit later if supported */
1149
			BUG_ON(stage2_pud_huge(*pud));
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165
			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;

1166
	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1167 1168 1169 1170
	do {
		/*
		 * Release kvm_mmu_lock periodically if the memory region is
		 * large. Otherwise, we may see kernel panics with
1171 1172
		 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
		 * CONFIG_LOCKDEP. Additionally, holding the lock too long
1173 1174 1175 1176 1177
		 * will also starve other vCPUs.
		 */
		if (need_resched() || spin_needbreak(&kvm->mmu_lock))
			cond_resched_lock(&kvm->mmu_lock);

1178 1179
		next = stage2_pgd_addr_end(addr, end);
		if (stage2_pgd_present(*pgd))
1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
			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)
{
1199 1200
	struct kvm_memslots *slots = kvm_memslots(kvm);
	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1201 1202 1203 1204 1205 1206 1207 1208
	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);
}
1209 1210

/**
1211
 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1212 1213 1214 1215 1216 1217 1218 1219 1220
 * @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.
 */
1221
static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1222 1223 1224 1225 1226 1227 1228 1229 1230
		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);
}
1231

1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245
/*
 * 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
1246
static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1247
				      unsigned long size)
1248
{
1249
	__coherent_cache_guest_page(vcpu, pfn, size);
1250 1251
}

1252
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1253
			  struct kvm_memory_slot *memslot, unsigned long hva,
1254 1255 1256
			  unsigned long fault_status)
{
	int ret;
1257
	bool write_fault, writable, hugetlb = false, force_pte = false;
1258
	unsigned long mmu_seq;
1259 1260
	gfn_t gfn = fault_ipa >> PAGE_SHIFT;
	struct kvm *kvm = vcpu->kvm;
1261
	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1262
	struct vm_area_struct *vma;
D
Dan Williams 已提交
1263
	kvm_pfn_t pfn;
1264
	pgprot_t mem_type = PAGE_S2;
1265 1266
	bool logging_active = memslot_is_logging(memslot);
	unsigned long flags = 0;
1267

1268
	write_fault = kvm_is_write_fault(vcpu);
1269 1270 1271 1272 1273
	if (fault_status == FSC_PERM && !write_fault) {
		kvm_err("Unexpected L2 read permission error\n");
		return -EFAULT;
	}

1274 1275 1276
	/* 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);
1277 1278 1279 1280 1281 1282
	if (unlikely(!vma)) {
		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
		up_read(&current->mm->mmap_sem);
		return -EFAULT;
	}

1283
	if (is_vm_hugetlb_page(vma) && !logging_active) {
1284 1285
		hugetlb = true;
		gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1286 1287
	} else {
		/*
1288 1289 1290 1291 1292 1293 1294
		 * 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.
1295
		 */
1296 1297
		if ((memslot->userspace_addr & ~PMD_MASK) !=
		    ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1298
			force_pte = true;
1299 1300 1301
	}
	up_read(&current->mm->mmap_sem);

1302
	/* We need minimum second+third level pages */
1303 1304
	ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
				     KVM_NR_MEM_OBJS);
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319
	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();

1320
	pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1321
	if (is_error_noslot_pfn(pfn))
1322 1323
		return -EFAULT;

1324
	if (kvm_is_device_pfn(pfn)) {
1325
		mem_type = PAGE_S2_DEVICE;
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342
		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;
	}
1343

1344 1345
	spin_lock(&kvm->mmu_lock);
	if (mmu_notifier_retry(kvm, mmu_seq))
1346
		goto out_unlock;
1347

1348 1349
	if (!hugetlb && !force_pte)
		hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1350 1351

	if (hugetlb) {
1352
		pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1353 1354
		new_pmd = pmd_mkhuge(new_pmd);
		if (writable) {
1355
			new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1356 1357
			kvm_set_pfn_dirty(pfn);
		}
1358
		coherent_cache_guest_page(vcpu, pfn, PMD_SIZE);
1359 1360
		ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
	} else {
1361
		pte_t new_pte = pfn_pte(pfn, mem_type);
1362

1363
		if (writable) {
1364
			new_pte = kvm_s2pte_mkwrite(new_pte);
1365
			kvm_set_pfn_dirty(pfn);
1366
			mark_page_dirty(kvm, gfn);
1367
		}
1368
		coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE);
1369
		ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1370
	}
1371

1372
out_unlock:
1373
	spin_unlock(&kvm->mmu_lock);
1374
	kvm_set_pfn_accessed(pfn);
1375
	kvm_release_pfn_clean(pfn);
1376
	return ret;
1377 1378
}

1379 1380 1381 1382
/*
 * 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.
1383 1384
 * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
 * so there is no need for atomic (pte|pmd)_mkyoung operations.
1385 1386 1387 1388 1389
 */
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
1390
	kvm_pfn_t pfn;
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400
	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;

1401
	if (pmd_thp_or_huge(*pmd)) {	/* THP, HugeTLB */
1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420
		*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);
}

1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432
/**
 * 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.
 */
1433 1434
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
1435 1436 1437
	unsigned long fault_status;
	phys_addr_t fault_ipa;
	struct kvm_memory_slot *memslot;
1438 1439
	unsigned long hva;
	bool is_iabt, write_fault, writable;
1440 1441 1442
	gfn_t gfn;
	int ret, idx;

1443
	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1444 1445 1446 1447 1448
	if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
		kvm_inject_vabt(vcpu);
		return 1;
	}

1449
	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1450

1451 1452
	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
1453 1454

	/* Check the stage-2 fault is trans. fault or write fault */
1455
	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1456 1457
	if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
	    fault_status != FSC_ACCESS) {
1458 1459 1460 1461
		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));
1462 1463 1464 1465 1466 1467
		return -EFAULT;
	}

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

	gfn = fault_ipa >> PAGE_SHIFT;
1468 1469
	memslot = gfn_to_memslot(vcpu->kvm, gfn);
	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1470
	write_fault = kvm_is_write_fault(vcpu);
1471
	if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1472 1473
		if (is_iabt) {
			/* Prefetch Abort on I/O address */
1474
			kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1475 1476 1477 1478
			ret = 1;
			goto out_unlock;
		}

1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494
		/*
		 * 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
1495 1496 1497 1498 1499 1500 1501
		/*
		 * 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
1502
		ret = io_mem_abort(vcpu, run, fault_ipa);
1503 1504 1505
		goto out_unlock;
	}

1506 1507 1508
	/* Userspace should not be able to register out-of-bounds IPAs */
	VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);

1509 1510 1511 1512 1513 1514
	if (fault_status == FSC_ACCESS) {
		handle_access_fault(vcpu, fault_ipa);
		ret = 1;
		goto out_unlock;
	}

1515
	ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1516 1517 1518 1519 1520
	if (ret == 0)
		ret = 1;
out_unlock:
	srcu_read_unlock(&vcpu->kvm->srcu, idx);
	return ret;
1521 1522
}

1523 1524 1525 1526
static int handle_hva_to_gpa(struct kvm *kvm,
			     unsigned long start,
			     unsigned long end,
			     int (*handler)(struct kvm *kvm,
1527 1528
					    gpa_t gpa, u64 size,
					    void *data),
1529
			     void *data)
1530 1531 1532
{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;
1533
	int ret = 0;
1534 1535 1536 1537 1538 1539

	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;
1540
		gfn_t gpa;
1541 1542 1543 1544 1545 1546 1547

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

1548 1549
		gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT;
		ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data);
1550
	}
1551 1552

	return ret;
1553 1554
}

1555
static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1556
{
1557
	unmap_stage2_range(kvm, gpa, size);
1558
	return 0;
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
}

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;
}

1584
static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1585 1586 1587
{
	pte_t *pte = (pte_t *)data;

1588
	WARN_ON(size != PAGE_SIZE);
1589 1590 1591 1592 1593 1594 1595 1596
	/*
	 * 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);
1597
	return 0;
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613
}


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);
}

1614
static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1615 1616 1617 1618
{
	pmd_t *pmd;
	pte_t *pte;

1619
	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1620 1621 1622 1623
	pmd = stage2_get_pmd(kvm, NULL, gpa);
	if (!pmd || pmd_none(*pmd))	/* Nothing there */
		return 0;

1624 1625
	if (pmd_thp_or_huge(*pmd))	/* THP, HugeTLB */
		return stage2_pmdp_test_and_clear_young(pmd);
1626 1627 1628 1629 1630

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

1631
	return stage2_ptep_test_and_clear_young(pte);
1632 1633
}

1634
static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1635 1636 1637 1638
{
	pmd_t *pmd;
	pte_t *pte;

1639
	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1640 1641 1642 1643
	pmd = stage2_get_pmd(kvm, NULL, gpa);
	if (!pmd || pmd_none(*pmd))	/* Nothing there */
		return 0;

1644
	if (pmd_thp_or_huge(*pmd))		/* THP, HugeTLB */
1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665
		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)
{
	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)
{
	trace_kvm_test_age_hva(hva);
	return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
}

1666 1667 1668 1669 1670
void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
{
	mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
}

1671 1672
phys_addr_t kvm_mmu_get_httbr(void)
{
1673 1674 1675 1676
	if (__kvm_cpu_uses_extended_idmap())
		return virt_to_phys(merged_hyp_pgd);
	else
		return virt_to_phys(hyp_pgd);
1677 1678
}

1679 1680 1681 1682 1683
phys_addr_t kvm_get_idmap_vector(void)
{
	return hyp_idmap_vector;
}

1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
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;
}

1700 1701
int kvm_mmu_init(void)
{
1702 1703
	int err;

1704 1705 1706
	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);
1707

1708 1709 1710 1711 1712
	/*
	 * 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);
1713

1714 1715
	kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
	kvm_info("HYP VA range: %lx:%lx\n",
M
Marc Zyngier 已提交
1716
		 kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
1717

M
Marc Zyngier 已提交
1718
	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1719 1720
	    hyp_idmap_start <  kern_hyp_va(~0UL) &&
	    hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1721 1722 1723 1724 1725 1726 1727 1728 1729
		/*
		 * 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;
	}

1730
	hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1731
	if (!hyp_pgd) {
1732
		kvm_err("Hyp mode PGD not allocated\n");
1733 1734 1735 1736
		err = -ENOMEM;
		goto out;
	}

1737 1738 1739 1740 1741 1742 1743 1744
	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;
		}
1745

1746 1747 1748
		err = kvm_map_idmap_text(boot_hyp_pgd);
		if (err)
			goto out;
1749

1750 1751 1752 1753 1754 1755 1756
		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);
1757 1758 1759 1760
	} else {
		err = kvm_map_idmap_text(hyp_pgd);
		if (err)
			goto out;
1761 1762
	}

1763
	return 0;
1764
out:
1765
	free_hyp_pgds();
1766
	return err;
1767
}
1768 1769

void kvm_arch_commit_memory_region(struct kvm *kvm,
1770
				   const struct kvm_userspace_memory_region *mem,
1771
				   const struct kvm_memory_slot *old,
1772
				   const struct kvm_memory_slot *new,
1773 1774
				   enum kvm_mr_change change)
{
1775 1776 1777 1778 1779 1780 1781
	/*
	 * 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);
1782 1783 1784 1785
}

int kvm_arch_prepare_memory_region(struct kvm *kvm,
				   struct kvm_memory_slot *memslot,
1786
				   const struct kvm_userspace_memory_region *mem,
1787 1788
				   enum kvm_mr_change change)
{
1789 1790 1791 1792 1793
	hva_t hva = mem->userspace_addr;
	hva_t reg_end = hva + mem->memory_size;
	bool writable = !(mem->flags & KVM_MEM_READONLY);
	int ret = 0;

1794 1795
	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
			change != KVM_MR_FLAGS_ONLY)
1796 1797
		return 0;

1798 1799 1800 1801 1802 1803 1804 1805
	/*
	 * 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;

1806
	down_read(&current->mm->mmap_sem);
1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
	/*
	 * 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);
1844 1845 1846 1847
			phys_addr_t pa;

			pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
			pa += vm_start - vma->vm_start;
1848

1849
			/* IO region dirty page logging not allowed */
1850 1851 1852 1853
			if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
				ret = -EINVAL;
				goto out;
			}
1854

1855 1856 1857 1858 1859 1860 1861 1862 1863
			ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
						    vm_end - vm_start,
						    writable);
			if (ret)
				break;
		}
		hva = vm_end;
	} while (hva < reg_end);

1864
	if (change == KVM_MR_FLAGS_ONLY)
1865
		goto out;
1866

1867 1868
	spin_lock(&kvm->mmu_lock);
	if (ret)
1869
		unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1870 1871 1872
	else
		stage2_flush_memslot(kvm, memslot);
	spin_unlock(&kvm->mmu_lock);
1873 1874
out:
	up_read(&current->mm->mmap_sem);
1875
	return ret;
1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888
}

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;
}

1889
void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1890 1891 1892 1893 1894
{
}

void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
1895
	kvm_free_stage2_pgd(kvm);
1896 1897 1898 1899 1900
}

void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
				   struct kvm_memory_slot *slot)
{
1901 1902 1903 1904 1905 1906
	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);
1907
}
1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975

/*
 * 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);
}