| Message ID | CACzj_yWd7Cusg6QmKn7roxMNgiip1U4s5EmoKTqzpkHYVH5CXw@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/05/2017 13:43, Wincy Van wrote: > I find that L2 can't boot in the kvm queue branch. > L0 KVM will inject a nested vmx exit reason 62 (EXIT_REASON_PML_FULL) > to L1, if L1 can't handle this exit reason, it will report a hardware error. > > According to my test, both RHEL 6.x (kernel 2.6.32) and VirtualBox for Windows > will be affected by this bug. > > Here is my workaround: > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 379087a..72784ac 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -8135,6 +8135,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) > * the XSS exit bitmap in vmcs12. > */ > return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES); > + case EXIT_REASON_PML_FULL: > + return false; > case EXIT_REASON_PREEMPTION_TIMER: > return false; > default: > > > If this patch applied, the bug seems to be fixed, but I can't ensure > that L0's pml is working properly in this scene. > > Is this patch doing the right thing (without implement nested pml)? Yes, the patch has been posted already (and will be in 4.12) as "[PATCH] KVM: nVMX: do not leak PML full vmexit to L1" Thanks, Paolo
On Tue, May 2, 2017 at 9:04 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > > > On 02/05/2017 13:43, Wincy Van wrote: >> I find that L2 can't boot in the kvm queue branch. >> L0 KVM will inject a nested vmx exit reason 62 (EXIT_REASON_PML_FULL) >> to L1, if L1 can't handle this exit reason, it will report a hardware error. >> >> According to my test, both RHEL 6.x (kernel 2.6.32) and VirtualBox for Windows >> will be affected by this bug. >> >> Here is my workaround: >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 379087a..72784ac 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -8135,6 +8135,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) >> * the XSS exit bitmap in vmcs12. >> */ >> return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES); >> + case EXIT_REASON_PML_FULL: >> + return false; >> case EXIT_REASON_PREEMPTION_TIMER: >> return false; >> default: >> >> >> If this patch applied, the bug seems to be fixed, but I can't ensure >> that L0's pml is working properly in this scene. >> >> Is this patch doing the right thing (without implement nested pml)? > > Yes, the patch has been posted already (and will be in 4.12) as "[PATCH] > KVM: nVMX: do not leak PML full vmexit to L1" > OK, missed that, thank you Paolo :-) Wincy
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 379087a..72784ac 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8135,6 +8135,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) * the XSS exit bitmap in vmcs12. */ return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES); + case EXIT_REASON_PML_FULL: + return false; case EXIT_REASON_PREEMPTION_TIMER: return false; default: