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| author | Marcelo Tosatti | 2009-05-12 23:55:45 +0200 |
|---|---|---|
| committer | Avi Kivity | 2009-06-10 10:48:55 +0200 |
| commit | 8986ecc0ef58c96eec48d8502c048f3ab67fd8e2 (patch) | |
| tree | b2682f02bcb1e437e62463a17d7adc95a6735b60 /arch/x86/kvm/mmu.c | |
| parent | KVM: take mmu_lock when updating a deleted slot (diff) | |
| download | kernel-qcow2-linux-8986ecc0ef58c96eec48d8502c048f3ab67fd8e2.tar.gz kernel-qcow2-linux-8986ecc0ef58c96eec48d8502c048f3ab67fd8e2.tar.xz kernel-qcow2-linux-8986ecc0ef58c96eec48d8502c048f3ab67fd8e2.zip | |
KVM: x86: check for cr3 validity in mmu_alloc_roots
Verify the cr3 address stored in vcpu->arch.cr3 points to an existant
memslot. If not, inject a triple fault.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 3ce60ad1fe37..5c3d6e81a7dc 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1912,7 +1912,19 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) vcpu->arch.mmu.root_hpa = INVALID_PAGE; } -static void mmu_alloc_roots(struct kvm_vcpu *vcpu) +static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) +{ + int ret = 0; + + if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) { + set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); + ret = 1; + } + + return ret; +} + +static int mmu_alloc_roots(struct kvm_vcpu *vcpu) { int i; gfn_t root_gfn; @@ -1927,13 +1939,15 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu) ASSERT(!VALID_PAGE(root)); if (tdp_enabled) direct = 1; + if (mmu_check_root(vcpu, root_gfn)) + return 1; sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL, direct, ACC_ALL, NULL); root = __pa(sp->spt); ++sp->root_count; vcpu->arch.mmu.root_hpa = root; - return; + return 0; } direct = !is_paging(vcpu); if (tdp_enabled) @@ -1950,6 +1964,8 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu) root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT; } else if (vcpu->arch.mmu.root_level == 0) root_gfn = 0; + if (mmu_check_root(vcpu, root_gfn)) + return 1; sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL, direct, ACC_ALL, NULL); @@ -1958,6 +1974,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu) vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; } vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); + return 0; } static void mmu_sync_roots(struct kvm_vcpu *vcpu) @@ -1976,7 +1993,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) for (i = 0; i < 4; ++i) { hpa_t root = vcpu->arch.mmu.pae_root[i]; - if (root) { + if (root && VALID_PAGE(root)) { root &= PT64_BASE_ADDR_MASK; sp = page_header(root); mmu_sync_children(vcpu, sp); @@ -2311,9 +2328,11 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) goto out; spin_lock(&vcpu->kvm->mmu_lock); kvm_mmu_free_some_pages(vcpu); - mmu_alloc_roots(vcpu); + r = mmu_alloc_roots(vcpu); mmu_sync_roots(vcpu); spin_unlock(&vcpu->kvm->mmu_lock); + if (r) + goto out; kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); kvm_mmu_flush_tlb(vcpu); out: |