diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-02-20 14:47:24 -0500 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 11:53:25 +0300 |
| commit | 2e53d63acba75795aa226febd140f67c58c6a353 (patch) | |
| tree | be4ad4e5b28c737053af78a950d270a657e9f628 /arch/x86/kvm/mmu.c | |
| parent | 847f0ad8cbfa70c1af6948025836dfbd9ed6da1e (diff) | |
KVM: MMU: ignore zapped root pagetables
Mark zapped root pagetables as invalid and ignore such pages during lookup.
This is a problem with the cr3-target feature, where a zapped root table fools
the faulting code into creating a read-only mapping. The result is a lockup
if the instruction can't be emulated.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index f7541fe22cd8..103d008dab8b 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -667,7 +667,8 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) index = kvm_page_table_hashfn(gfn); bucket = &kvm->arch.mmu_page_hash[index]; hlist_for_each_entry(sp, node, bucket, hash_link) - if (sp->gfn == gfn && !sp->role.metaphysical) { + if (sp->gfn == gfn && !sp->role.metaphysical + && !sp->role.invalid) { pgprintk("%s: found role %x\n", __FUNCTION__, sp->role.word); return sp; @@ -792,8 +793,11 @@ static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp) if (!sp->root_count) { hlist_del(&sp->hash_link); kvm_mmu_free_page(kvm, sp); - } else + } else { list_move(&sp->link, &kvm->arch.active_mmu_pages); + sp->role.invalid = 1; + kvm_reload_remote_mmus(kvm); + } kvm_mmu_reset_last_pte_updated(kvm); } @@ -1073,6 +1077,8 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) sp = page_header(root); --sp->root_count; + if (!sp->root_count && sp->role.invalid) + kvm_mmu_zap_page(vcpu->kvm, sp); vcpu->arch.mmu.root_hpa = INVALID_PAGE; spin_unlock(&vcpu->kvm->mmu_lock); return; @@ -1085,6 +1091,8 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) root &= PT64_BASE_ADDR_MASK; sp = page_header(root); --sp->root_count; + if (!sp->root_count && sp->role.invalid) + kvm_mmu_zap_page(vcpu->kvm, sp); } vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; } |