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Revert "KVM: MMU: Move kvm_mmu_free_some_pages() into kvm_mmu_alloc_page()"

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With the following commit, shadow pages can be zapped at random during
a shadow page talbe walk:
  KVM: MMU: Move kvm_mmu_free_some_pages() into kvm_mmu_alloc_page()
  7ddca7e43c

This patch reverts it and fixes __direct_map() and FNAME(fetch)().

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This commit is contained in:
Takuya Yoshikawa 2013-03-29 14:05:26 +09:00 committed by Gleb Natapov
parent afd80d85ae
commit 450e0b411f
2 changed files with 8 additions and 4 deletions
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11
arch/x86/kvm/mmu.c
View file

@ -1501,15 +1501,11 @@ static void drop_parent_pte(struct kvm_mmu_page *sp,
mmu_spte_clear_no_track(parent_pte);
}
static void make_mmu_pages_available(struct kvm_vcpu *vcpu);
static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
u64 *parent_pte, int direct)
{
struct kvm_mmu_page *sp;
make_mmu_pages_available(vcpu);
sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache);
if (!direct)
@ -2806,6 +2802,7 @@ exit:
static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
gva_t gva, pfn_t *pfn, bool write, bool *writable);
static void make_mmu_pages_available(struct kvm_vcpu *vcpu);
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
gfn_t gfn, bool prefault)
@ -2847,6 +2844,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
make_mmu_pages_available(vcpu);
if (likely(!force_pt_level))
transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
r = __direct_map(vcpu, v, write, map_writable, level, gfn, pfn,
@ -2924,6 +2922,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL,
1, ACC_ALL, NULL);
++sp->root_count;
@ -2935,6 +2934,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
ASSERT(!VALID_PAGE(root));
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),
i << 30,
PT32_ROOT_LEVEL, 1, ACC_ALL,
@ -2973,6 +2973,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
ASSERT(!VALID_PAGE(root));
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,
0, ACC_ALL, NULL);
root = __pa(sp->spt);
@ -3006,6 +3007,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
return 1;
}
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
PT32_ROOT_LEVEL, 0,
ACC_ALL, NULL);
@ -3311,6 +3313,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
make_mmu_pages_available(vcpu);
if (likely(!force_pt_level))
transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
r = __direct_map(vcpu, gpa, write, map_writable,

1
arch/x86/kvm/paging_tmpl.h
View file

@ -627,6 +627,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
goto out_unlock;
kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
make_mmu_pages_available(vcpu);
if (!force_pt_level)
transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
r = FNAME(fetch)(vcpu, addr, &walker, write_fault,