diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index a43f4ccd30bb..2b3d66c7b68d 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -746,6 +746,14 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, * Using the cached information from sp->gfns is safe because: * - The spte has a reference to the struct page, so the pfn for a given gfn * can't change unless all sptes pointing to it are nuked first. + * + * Note: + * We should flush all tlbs if spte is dropped even though guest is + * responsible for it. Since if we don't, kvm_mmu_notifier_invalidate_page + * and kvm_mmu_notifier_invalidate_range_start detect the mapping page isn't + * used by guest then tlbs are not flushed, so guest is allowed to access the + * freed pages. + * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. */ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { @@ -781,14 +789,14 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) gfn = gpte_to_gfn(gpte); if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { - kvm_flush_remote_tlbs(vcpu->kvm); + vcpu->kvm->tlbs_dirty++; continue; } if (gfn != sp->gfns[i]) { drop_spte(vcpu->kvm, &sp->spt[i], shadow_trap_nonpresent_pte); - kvm_flush_remote_tlbs(vcpu->kvm); + vcpu->kvm->tlbs_dirty++; continue; } |