Re: [PATCH 3/5] KVM: Adds ability to preepmt an executing VCPU

["Gregory Haskins" <ghaskins-Et1tbQHTxzrQT0dZR+AlfA@public.gmane.org>]

>>> On Tue, Apr 24, 2007 at  5:17 AM, in message <462DCB3E.6070802-atKUWr5tajBWk0Htik3J/w@public.gmane.org>,
Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org> wrote: 
> Gregory Haskins wrote:
> 
>> Are there any other userspace sleeps that we need to handle (e.g. maybe 
> AIO)?  If so, one way to handle this is to mark the exportable state of the 
> VCPU such that userspace can tell if interrupts are pending.  However, I'm 
> not really sure if this is the best way to do it or if it can be easily done 
> in a way that doesn't break ABI compatiblity.  Please advise. 
>>   
> 
> The ABI can be extended by adding fields to struct kvm_vcpu_run and an
> extension check to indicate their availability.

Cool.  I was not aware of that capability.  In that case, I think the reasonable thing to do is just that (extend to allow "pending" status).  If the new userspace (which will implicitly understand the presence of an in-kernel APIC) needs to know, it can be coded to check this state.

-Greg




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