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
