Re: [Qemu-devel] KVM: Windows 64-bit troubles with user space irqchip

[Avi Kivity]

On 02/02/2011 05:52 PM, Jan Kiszka wrote:
> >>
> >  If there is no problem in the logic of this commit (and I do not see
> >  one yet) then we somewhere miss kicking vcpu when interrupt, that should be
> >  handled, arrives?
>
> I'm not yet confident about the logic of the kernel patch: mov to cr8 is
> serializing. If the guest raises the tpr and then signals this with a
> succeeding, non vm-exiting instruction to the other vcpus, one of those
> could inject an interrupt with a higher priority than the previous tpr,
> but a lower one than current tpr. QEMU user space would accept this
> interrupt - and would likely surprise the guest. Do I miss something?

apic_get_interrupt() is only called from the vcpu thread, so it should 
see a correct tpr.

The only difference I can see with the patch is that we may issue a 
spurious cpu_interrupt().  But that shouldn't do anything bad, should it?

--
error compiling committee.c: too many arguments to function