Re: [PATCH v3 1/4] KVM: Recover IRTE to remapped mode if the interrupt is not single-destination

From: Paolo Bonzini
Date: Mon Jan 25 2016 - 07:22:52 EST




On 22/01/2016 14:05, Radim KrcmÃr wrote:
> > This is a good question. I also thought about this before, but after
> > thinking it a bit more, seems we don't need to do this.
> > If we don't do this, the in-flight interrupts will continue to be
> > delivered in PI mode while we are changing it to remapped
> > mode in IRTE. Even if we do this, the in-flight interrupts are
> > also delivered in PI mode before setting 'SN' anyway, so seems
> > we really don't need this, what is your opinion?
> I'd remove it.

It may be necessary because IRTE writes (128 bits) are not atomic.

If so, no need to send v5, I'll add it back.

Paolo