Dirk Müller <[email protected]> writes: >> I added the warning so that we catch if the next_rip field is being written >> to (even if the feature isn't supported) by a buggy L1 hypervisor. > > Interesting, so how about this patch? > > > From c5c8ea255d680f972cbdfc835cdf352fa78897ae Mon Sep 17 00:00:00 2001 > From: Dirk Mueller <[email protected]> > Date: Fri, 2 Oct 2015 08:35:24 +0200 > Subject: [PATCH] KVM: nSVM: Check for NRIP support before accepting > control.next_rip > > NRIP support itself depends on cpuid Fn8000_000A_EDX[NRIPS], remove > a WARN_ON_(once) and check for it directly. > > Signed-off-by: Dirk Mueller <[email protected]> > --- > arch/x86/kvm/svm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 0a42859..33d36da 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -513,8 +513,8 @@ static void skip_emulated_instruction(struct kvm_vcpu > *vcpu) > { > struct vcpu_svm *svm = to_svm(vcpu); > > - if (svm->vmcb->control.next_rip != 0) { > - WARN_ON_ONCE(!static_cpu_has(X86_FEATURE_NRIPS)); > + if (static_cpu_has(X86_FEATURE_NRIPS) && > + svm->vmcb->control.next_rip != 0) { > svm->next_rip = svm->vmcb->control.next_rip; > }
Ok, looks good to me. Still, probably a good idea to let the user know if this condition is hit. Bandan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
