Re: [PATCH] KVM: arm64: vgic-v4: Consistently request doorbell irq for blocking vCPU

[Oliver Upton <oliver.upton@linux.dev>]

On Wed, Jul 12, 2023 at 02:49:15PM +0100, Marc Zyngier wrote:
> > Given that making VPE resident on the vcpu block path (i.e., in
> > kvm_vcpu_halt()) makes little sense (right?) and leads to this sort of
> > problem, a crude idea is that we can probably keep track of the
> > "nested" vgic_v4_{put,load} calls (instead of a single vpe->resident
> > flag) and keep VPE *not resident* on the whole block path (like what we
> > had before commit 8e01d9a396e6). And we then rely on
> > kvm_vcpu_wfi/vgic_v4_load to actually schedule the VPE on...
> 
> I'm not sure about the nested tracking part, but it's easy enough to
> have a vcpu flag indicating that we're in WFI. So an *alternative* to
> the current fix would be something like this:

Yeah, I like your approach better. I've gone ahead and backed out my
change and can take this instead once someone tests it out :)

-- 
Thanks,
Oliver