On 4/8/21 2:48 PM, Sean Christopherson wrote: > On Thu, Apr 08, 2021, Tom Lendacky wrote: >> >> >> On 4/8/21 12:37 PM, Sean Christopherson wrote: >>> On Thu, Apr 08, 2021, Tom Lendacky wrote: >>>> On 4/8/21 12:10 PM, Sean Christopherson wrote: >>>>> On Thu, Apr 08, 2021, Tom Lendacky wrote: >>>>>> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c >>>>>> index 83e00e524513..7ac67615c070 100644 >>>>>> --- a/arch/x86/kvm/svm/sev.c >>>>>> +++ b/arch/x86/kvm/svm/sev.c >>>>>> @@ -2105,5 +2105,8 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu >>>>>> *vcpu, u8 vector) >>>>>> * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a >>>>>> * non-zero value. >>>>>> */ >>>>>> + if (WARN_ON_ONCE(!svm->ghcb)) >>>>> >>>>> Isn't this guest triggerable? I.e. send a SIPI without doing the reset >>>>> hold? >>>>> If so, this should not WARN. >>>> >>>> Yes, it is a guest triggerable event. But a guest shouldn't be doing that, >>>> so I thought adding the WARN_ON_ONCE() just to detect it wasn't bad. >>>> Definitely wouldn't want a WARN_ON(). >>> >>> WARNs are intended only for host issues, e.g. a malicious guest shouldn't be >>> able to crash the host when running with panic_on_warn. >>> >> >> Ah, yeah, forgot about panic_on_warn. I can go back to the original patch >> or do a pr_warn_once(), any pref? > > No strong preference. If you think the print would be helpful for ongoing > development, then it's probably worth adding.
For development, I'd want to see it all the time. But since it is guest triggerable, the _once() method is really needed in production. So in the latest version I just dropped the message/notification. Thanks, Tom >
