Re: [RFC PATCH] hw/arm/virt: Support NMI injection

[Gavin Shan]

On 1/29/20 8:04 PM, Marc Zyngier wrote:
> On 2020-01-29 02:44, Alexey Kardashevskiy wrote:
> > On 28/01/2020 17:48, Gavin Shan wrote:
> > > but a NMI is injected
> > > through LAPIC on x86. So I'm not sure what architect (system reset on
> > > ppc or injecting NMI on x86) aarch64 should follow.
> >
> > I'd say whatever triggers in-kernel debugger or kdump but I am not
> > familiar with ARM at all :)
>
> All that is completely OS specific, and has no relation to the architecture.
> As I mentioned in another part of the thread, the closest thing to this
> would be to implement SDEI together with an IMPDEF mechanism to enter it
> (or even generate a RAS error).
>
> On the other hand, SDEI is pretty horrible, and means either KVM or QEMU
> acting like a firmware for the guest. To say that I'm not keen is a massive
> understatement.
>
>          M.

Marc, could you please explain a bit about "IMPDEF mechanism"? I'm not sure if
it means a non-standard SDEI event should be used, corresponding to the HMP/QMP
"nmi" command.

Also, If I'm correct, you agree that a crash dump should be triggered on arm64
guest once HMP/QMP "nmi" command is issued? I also dig into SDEI a bit. It seems
the SDEI support in QEMU isn't upstream yet:


https://patchew.org/QEMU/address@hidden/

Thanks,
Gavin