Re: [RESEND 2][PATCH 4/4] Modify KVM to update guest time accounting.

[Avi Kivity]

Laurent Vivier wrote:
> Avi Kivity wrote:
>   
> > Ingo Molnar wrote:
> >     
> > > * Avi Kivity <avi@xxxxxxxxxxxx> wrote:
> > >
> > >  
> > >       
> > > > This bit can go; for the external module I can add it back in
> > > > external-module-compat.h.  No need to pollute mainline with backward
> > > > compatibility stuff.
> > > >     
> > > >         
> > > hm:
> > >
> > > static inline void kvm_guest_enter(void)
> > > {
> > >         current->flags |= PF_VCPU;
> > > }
> > >
> > > static inline void kvm_guest_exit(void)
> > > {
> > > }
> > >
> > > shouldnt PF_VCPU be cleared in kvm_guest_exit()?
> > >   
> > >       
> > IIRC the accounting code clears it, but yes, it may not have been called
> > at all, so clearing it here is needed.
> >
> >     
>
> No, It must not be cleared here because we can't enter in the accounting code
> between kvm_guest_enter(void) and kvm_guest_exit(void).
>
>   

Right.

> This is why the accounting code clears it.
>   

But if we didn't get an interrupt in that time?

We can clear it a bit later, after local_irq_enable() in __vcpu_run().  
However we need a nop instruction first because "sti" keeps interrupts 
disabled for one more instruction.


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

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