Re: [Qemu-devel] [PATCH v2 5/6] x86: fix up 32 bit phys_bits case

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Daniel P. Berrange (berrange@redhat.com) wrote:
> On Mon, Jul 04, 2016 at 08:16:08PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > On 32 bit systems fix up phys_bits to be consistent with what
> > we tell the guest; don't ever bother with using the phys_bits
> > property.
> 
> > @@ -2990,6 +2986,15 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
> >              cpu->phys_bits = host_phys_bits;
> >  
> >          }
> > +    } else {
> > +        /* For 32 bit systems don't use the user set value, but keep
> > +         * phys_bits consistent with what we tell the guest.
> > +         */
> > +        if (env->features[FEAT_1_EDX] & CPUID_PSE36) {
> > +            cpu->phys_bits = 36;
> > +        } else {
> > +            cpu->phys_bits = 32;
> > +        }
> 
> I kind of feel like we should report an error and exit if the
> user/app has provided a phys_bits property value, rather than
> silently ignoring their provided value, on the basis that this
> is a user/app configuration error.

Do we have an easy way to tell that the user has set the parameter
as opposed to it being the default?

Dave

> Regards,
> Daniel
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--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK