From a1708ce8a362c4999f1201237ae7b77c4d13af82 Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Fri, 25 Jul 2008 16:26:39 +0200 Subject: [PATCH] KVM: Allow reading aliases with mmu_lock This allows the mmu notifier code to run unalias_gfn with only the mmu_lock held. Only alias writes need the mmu_lock held. Readers will either take the slots_lock in read mode or the mmu_lock. Signed-off-by: Andrea Arcangeli Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5916191420c..9870ce42292 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1495,6 +1495,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, goto out; down_write(&kvm->slots_lock); + spin_lock(&kvm->mmu_lock); p = &kvm->arch.aliases[alias->slot]; p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT; @@ -1506,6 +1507,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, break; kvm->arch.naliases = n; + spin_unlock(&kvm->mmu_lock); kvm_mmu_zap_all(kvm); up_write(&kvm->slots_lock); -- 2.41.1