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authorJoerg Roedel <joerg.roedel@amd.com>2008-08-27 08:18:43 -0400
committerAvi Kivity <avi@qumranet.com>2008-09-11 04:31:53 -0400
commit44874f84918e37b64bec6df1587e5fe2fdf6ab62 (patch)
tree8fc95bb2358322ddd9307d231849d7c0a064b001 /arch
parentadee14b2e1557d0a8559f29681732d05a89dfc35 (diff)
KVM: SVM: fix random segfaults with NPT enabled
This patch introduces a guest TLB flush on every NPF exit in KVM. This fixes random segfaults and #UD exceptions in the guest seen under some workloads (e.g. long running compile workloads or tbench). A kernbench run with and without that fix showed that it has a slowdown lower than 0.5% Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e2ee264740c7..d1106cddab0d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -62,6 +62,7 @@ static int npt = 1;
62module_param(npt, int, S_IRUGO); 62module_param(npt, int, S_IRUGO);
63 63
64static void kvm_reput_irq(struct vcpu_svm *svm); 64static void kvm_reput_irq(struct vcpu_svm *svm);
65static void svm_flush_tlb(struct kvm_vcpu *vcpu);
65 66
66static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) 67static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
67{ 68{
@@ -1027,6 +1028,13 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
1027 KVMTRACE_3D(TDP_FAULT, &svm->vcpu, error_code, 1028 KVMTRACE_3D(TDP_FAULT, &svm->vcpu, error_code,
1028 (u32)fault_address, (u32)(fault_address >> 32), 1029 (u32)fault_address, (u32)(fault_address >> 32),
1029 handler); 1030 handler);
1031 /*
1032 * FIXME: Tis shouldn't be necessary here, but there is a flush
1033 * missing in the MMU code. Until we find this bug, flush the
1034 * complete TLB here on an NPF
1035 */
1036 if (npt_enabled)
1037 svm_flush_tlb(&svm->vcpu);
1030 1038
1031 if (event_injection) 1039 if (event_injection)
1032 kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address); 1040 kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);