From 7b53aa56508479507c6e5667bb252ca7c2cd19cf Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 5 Jun 2007 12:17:03 +0300 Subject: [PATCH] KVM: Fix vcpu freeing for guest smp A vcpu can pin up to four mmu shadow pages, which means the freeing loop will never terminate. Fix by first unpinning shadow pages on all vcpus, then freeing shadow pages. Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 15 +++++++++++++++ drivers/kvm/mmu.c | 4 ++-- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 3c3231d8dabf..3ff8ee56279c 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -381,6 +381,16 @@ static void free_pio_guest_pages(struct kvm_vcpu *vcpu) } } +static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu) +{ + if (!vcpu->vmcs) + return; + + vcpu_load(vcpu); + kvm_mmu_unload(vcpu); + vcpu_put(vcpu); +} + static void kvm_free_vcpu(struct kvm_vcpu *vcpu) { if (!vcpu->vmcs) @@ -401,6 +411,11 @@ static void kvm_free_vcpus(struct kvm *kvm) { unsigned int i; + /* + * Unpin any mmu pages first. + */ + for (i = 0; i < KVM_MAX_VCPUS; ++i) + kvm_unload_vcpu_mmu(&kvm->vcpus[i]); for (i = 0; i < KVM_MAX_VCPUS; ++i) kvm_free_vcpu(&kvm->vcpus[i]); } diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 5915d7a1c4f7..d4de988d1828 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -838,11 +838,12 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) int i; struct kvm_mmu_page *page; + if (!VALID_PAGE(vcpu->mmu.root_hpa)) + return; #ifdef CONFIG_X86_64 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->mmu.root_hpa; - ASSERT(VALID_PAGE(root)); page = page_header(root); --page->root_count; vcpu->mmu.root_hpa = INVALID_PAGE; @@ -853,7 +854,6 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) hpa_t root = vcpu->mmu.pae_root[i]; if (root) { - ASSERT(VALID_PAGE(root)); root &= PT64_BASE_ADDR_MASK; page = page_header(root); --page->root_count; -- 2.20.1