Re: [PATCH v2 00/43] KVM: Halt-polling and x86 APICv overhaul

[Paolo Bonzini]

On 27/10/21 17:28, Sean Christopherson wrote:
> On Wed, Oct 27, 2021, Paolo Bonzini wrote:
> > On 27/10/21 16:41, Sean Christopherson wrote:
> > > The other thing I don't like about having the WARN in the loop is that it suggests
> > > that something other than the vCPU can modify the NDST and SN fields, which is
> > > wrong and confusing (for me).
> >
> > Yeah, I can agree with that.  Can you add it in a comment above the cmpxchg
> > loop, it can be as simple as
> >
> > 	/* The processor can set ON concurrently.  */
> >
> > when you respin patch 21 and the rest of the series?
>
> I can definitely add a comment, but I think that comment is incorrect.

It's completely backwards indeed.  I first had "the hardware" and then 
shut down my brain for a second to replace it.

> So something like this?
>
> 	/* ON can be set concurrently by a different vCPU or by hardware. */

Yes, of course.

Paolo