Re: [PATCH] arm/monitor vm-events: Implement guest-request support

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Fri, 19 Feb 2016, Corneliu ZUZU wrote:
> On 2/19/2016 6:05 PM, Andrew Cooper wrote:
> > On 19/02/16 16:00, Stefano Stabellini wrote:
> > > On Fri, 19 Feb 2016, Corneliu ZUZU wrote:
> > > > On 2/19/2016 3:49 PM, Stefano Stabellini wrote:
> > > > > On Thu, 18 Feb 2016, Corneliu ZUZU wrote:
> > > > > > +
> > > > > > +    if ( sync )
> > > > > > +    {
> > > > > > +        req->flags |= VM_EVENT_FLAG_VCPU_PAUSED;
> > > > > > +        vm_event_vcpu_pause(v);
> > > > > > +    }
> > > > > > +
> > > > > > +#if CONFIG_X86
> > > > > > +    if ( altp2m_active(d) )
> > > > > I would rather
> > > > > 
> > > > > #define altp2m_active(d) (0)
> > > > > 
> > > > > on ARM, removing the two ifdefs in this file.
> > > > Yeah, I actually wanted to get rid of that too at some point, the
> > > > question is,
> > > > what do I do with "req->altp2m_idx = vcpu_altp2m(v).p2midx"? I'm not
> > > > familiar
> > > > w/ altp2m design, maybe someone that knows more of the internals of that
> > > > can
> > > > give a suggestion.
> > > If you #define altp2m_active to (0), gcc will automatically avoid the if
> > > statement.
> > You will still get the compile error from ARM's struct vcpu not having
> > altp2m information.
> > 
> > ~Andrew
> > 
> 
> Yep.

Yes, you are right, especially given that Xen is compiled -Wall -Werror.

How do you plan to introduce altp2m support on ARM? Is there going to be
a struct altp2mvcpu on ARM too? It is not nice to access stuff under
v->arch from common code. Maybe we need another arch_blah function to
set altp2m_idx.