Re: [PATCH v2] kvm: Replace vcpu->swait with rcuwait

[Davidlohr Bueso]

On Mon, 20 Apr 2020, Paolo Bonzini wrote:

> On 20/04/20 22:56, Davidlohr Bueso wrote:
> > On Mon, 20 Apr 2020, Marc Zyngier wrote:
> >
> > > This looks like a change in the semantics of the tracepoint. Before this
> > > change, 'waited' would have been true if the vcpu waited at all. Here,
> > > you'd
> > > have false if it has been interrupted by a signal, even if the vcpu
> > > has waited
> > > for a period of time.
> >
> > Hmm but sleeps are now uninterruptible as we're using TASK_IDLE.
>
> Hold on, does that mean that you can't anymore send a signal in order to
> kick a thread out of KVM_RUN?  Or am I just misunderstanding?

Considering that the return value of the interruptible wait is not
checked, I would not think this breaks KVM_RUN.

Thanks,
Davidlohr