diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e552fd5cd33d..5f0864000360 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2101,6 +2101,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct * depends on valid pages being added to the head of the list. See * comments in kvm_zap_obsolete_pages(). */ + sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); kvm_mod_used_mmu_pages(vcpu->kvm, +1); return sp; @@ -2537,7 +2538,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, if (level > PT_PAGE_TABLE_LEVEL && need_sync) flush |= kvm_sync_pages(vcpu, gfn, &invalid_list); } - sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; clear_page(sp->spt); trace_kvm_mmu_get_page(sp, true); @@ -5738,9 +5738,19 @@ restart: */ static void kvm_mmu_zap_all_fast(struct kvm *kvm) { + lockdep_assert_held(&kvm->slots_lock); + spin_lock(&kvm->mmu_lock); trace_kvm_mmu_zap_all_fast(kvm); - kvm->arch.mmu_valid_gen++; + + /* + * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is + * held for the entire duration of zapping obsolete pages, it's + * impossible for there to be multiple invalid generations associated + * with *valid* shadow pages at any given time, i.e. there is exactly + * one valid generation and (at most) one invalid generation. + */ + kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; /* * Notify all vcpus to reload its shadow page table and flush TLB. |