Re: [Qemu-devel][PATCH] x86/cpu: Use max host physical address if -cpu max option is applied

[Paolo Bonzini <pbonzini@redhat.com>]

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Yes, thanks.

Paolo


Il mer 13 gen 2021, 15:52 Yang Weijiang <weijiang.yang@intel.com> ha
scritto:

> On Wed, Jan 13, 2021 at 11:06:09AM +0100, Paolo Bonzini wrote:
> > On 13/01/21 10:04, Yang Weijiang wrote:
> > > QEMU option -cpu max(max_features) means "Enables all features
> supported by
> > > the accelerator in the current host", this looks true for all the
> features
> > > except guest max physical address width, so add this patch to enable
> it.
> > >
> > > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
> > > ---
> > >   target/i386/cpu.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > > index 35459a38bb..b5943406f7 100644
> > > --- a/target/i386/cpu.c
> > > +++ b/target/i386/cpu.c
> > > @@ -6673,7 +6673,7 @@ static void x86_cpu_realizefn(DeviceState *dev,
> Error **errp)
> > >                   warned = true;
> > >               }
> > > -            if (cpu->host_phys_bits) {
> > > +            if (cpu->host_phys_bits || cpu->max_features) {
> > >                   /* The user asked for us to use the host physical
> bits */
> > >                   cpu->phys_bits = host_phys_bits;
> > >                   if (cpu->host_phys_bits_limit &&
> > >
> >
> > Can you check if this works?
> >
> Hi, Paolo,
> Yes, below change works for kvm-unit-test/access. Would you add the
> patch?
>
> Thanks!
>
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index 35459a38bb..72a79e6019 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -4319,6 +4319,7 @@ static void max_x86_cpu_initfn(Object *obj)
> >          if (lmce_supported()) {
> >              object_property_set_bool(OBJECT(cpu), "lmce", true,
> > &error_abort);
> >          }
> > +        object_property_set_bool(OBJECT(cpu), "host-phys-bits", true,
> > &error_abort);
> >      } else {
> >          object_property_set_str(OBJECT(cpu), "vendor", CPUID_VENDOR_AMD,
> >                                  &error_abort);
> >
> >
> > It should allow people to use -cpu max,host-phys-bits=false.
> >
> > Thanks,
> >
> > Paolo
>
>

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