Re: [PATCH v6 13/18] KVM: arm64: Support SDEI_EVENT_{COMPLETE,COMPLETE_AND_RESUME} hypercall

From: Oliver Upton
Date: Sun May 01 2022 - 03:01:53 EST


On Sun, Apr 03, 2022 at 11:39:06PM +0800, Gavin Shan wrote:
> This supports SDEI_EVENT_{COMPLETE, COMPLETE_AND_RESUME} hypercall.
> They are used by guest to notify the completion of event in its
> handler. The previously interrupted or preempted context is restored
> like below.
>
> * x0 - x17, PC and PState are restored to what values we had in
> the interrupted or preempted context.
>
> * If it's SDEI_EVENT_COMPLETE_AND_RESUME hypercall, IRQ exception
> is injected.

I don't think that's how COMPLETE_AND_RESUME works. The caller specifies an
address at which it would like to begin execution within the client
exception level.

SDEI spec suggests this behaves like a synchronous exception. DEN 0054C
5.2.2 'Event Resume Context' speaks more about how it is supposed to
work.

--
Thanks,
Oliver