Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH] KVM/VMX: Invoke NMI non-IST entry instead of IST entry | Date | Wed, 05 May 2021 02:00:10 +0200 |
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On Tue, May 04 2021 at 23:56, Paolo Bonzini wrote: > On 04/05/21 23:51, Sean Christopherson wrote: >> On Tue, May 04, 2021, Paolo Bonzini wrote: >>> On 04/05/21 23:23, Andy Lutomirski wrote: >>>>> On May 4, 2021, at 2:21 PM, Sean Christopherson <seanjc@google.com> wrote: >>>>> FWIW, NMIs are masked if the VM-Exit was due to an NMI. >>> >>> Huh, indeed: "An NMI causes subsequent NMIs to be blocked, but only after >>> the VM exit completes". >>> >>>> Then this whole change is busted, since nothing will unmask NMIs. Revert it? >>> Looks like the easiest way out indeed. >> >> I've no objection to reverting to intn, but what does reverting versus handling >> NMI on the kernel stack have to do with NMIs being blocked on VM-Exit due to NMI? >> I'm struggling mightily to connect the dots. > > Nah, you're right: vmx_do_interrupt_nmi_irqoff will not call the handler > directly, rather it calls the IDT entrypoint which *will* do an IRET and > unmask NMIs. I trusted Andy too much on this one. :) > > Thomas's posted patch ("[PATCH] KVM/VMX: Invoke NMI non-IST entry > instead of IST entry") looks good.
Well, looks good is one thing.
It would be more helpful if someone would actually review and/or test it.
Thanks,
tglx
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