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| author | Joerg Roedel <joerg.roedel@amd.com> | 2008-09-13 08:38:41 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-08 20:22:54 -0700 |
| commit | feec4f615504a766e1897412d5a9a28b1c4eec6c (patch) | |
| tree | fb92d46a46533eff2297c4e2e9d86d9d847e2d89 | |
| parent | 7fa544746f2837f5d743b50e638fa60dd36da5a8 (diff) | |
| download | lwn-feec4f615504a766e1897412d5a9a28b1c4eec6c.tar.gz lwn-feec4f615504a766e1897412d5a9a28b1c4eec6c.zip | |
KVM: SVM: fix random segfaults with NPT enabled
(cherry picked from commit 44874f84918e37b64bec6df1587e5fe2fdf6ab62)
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%
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/kvm/svm.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 7d6071d11eb8..fe88513a3296 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -60,6 +60,7 @@ static int npt = 1; module_param(npt, int, S_IRUGO); static void kvm_reput_irq(struct vcpu_svm *svm); +static void svm_flush_tlb(struct kvm_vcpu *vcpu); static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) { @@ -1017,6 +1018,15 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) fault_address = svm->vmcb->control.exit_info_2; error_code = svm->vmcb->control.exit_info_1; + + /* + * FIXME: Tis shouldn't be necessary here, but there is a flush + * missing in the MMU code. Until we find this bug, flush the + * complete TLB here on an NPF + */ + if (npt_enabled) + svm_flush_tlb(&svm->vcpu); + if (event_injection) kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address); return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code); |