Re: [Qemu-devel] [PATCH] qemu: fix cpuid eax for kvm cpu

[Avi Kivity]

On 05/01/2012 03:49 PM, Michael S. Tsirkin wrote:
> On Tue, May 01, 2012 at 03:38:43PM +0300, Avi Kivity wrote:
> > On 04/30/2012 05:42 PM, Michael S. Tsirkin wrote:
> > > cpuid eax should return the max leaf so that
> > > guests can find out the valid range.
> > > This matches Xen et al.
> > >
> > > Tested using -cpu kvm64.
> > >
> > > Signed-off-by: Michael S. Tsirkin <address@hidden>
> > > ---
> > >  target-i386/kvm.c |    2 +-
> > >  1 files changed, 1 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> > > index e74a9e4..c097248 100644
> > > --- a/target-i386/kvm.c
> > > +++ b/target-i386/kvm.c
> > > @@ -379,7 +379,7 @@ int kvm_arch_init_vcpu(CPUX86State *env)
> > >      c->function = KVM_CPUID_SIGNATURE;
> > >      if (!hyperv_enabled()) {
> > >          memcpy(signature, "KVMKVMKVM\0\0\0", 12);
> > > -        c->eax = 0;
> > > +        c->eax = KVM_CPUID_FEATURES;
> > >      } else {
> > >          memcpy(signature, "Microsoft Hv", 12);
> > >          c->eax = HYPERV_CPUID_MIN;
> > 
> > Should only change for -M 1.1+?
>
> I don't think we should: it's a bug fix and we don't try to be bug for
> bug compatible unless fixing the bug actually affects guest behaviour.
>

I agree.

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