Re: [Qemu-devel] [PATCH v3 05/17] target-i386: Add x86_set_hyperv.

[Don Slutz]

On 09/19/12 15:32, Eduardo Habkost wrote:
> On Mon, Sep 17, 2012 at 10:00:55AM -0400, Don Slutz wrote:
> > This is used to set the cpu object's hypervisor level to the default for 
> > Microsoft's Hypervisor.
> >
> > Signed-off-by: Don Slutz <address@hidden>
> > ---
> >   target-i386/cpu.c |   10 ++++++++++
> >   1 files changed, 10 insertions(+), 0 deletions(-)
> >
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 0e4a18d..4120393 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -1192,6 +1192,13 @@ static void x86_cpuid_set_hv_level(Object *obj, Visitor 
> > *v, void *opaque,
> >   }
> >
> >   #if !defined(CONFIG_USER_ONLY)
> > +static void x86_set_hyperv(Object *obj, Error **errp)
> > +{
> > +    X86CPU *cpu = X86_CPU(obj);
> > +
> > +    cpu->env.cpuid_hv_level = HYPERV_CPUID_MIN;
> HYPERV_CPUID_MIN is defined on linux-headers/asm-x86/hyperv.h, that is
> included only if build host is linux-x86 and CONFIG_KVM is set.
Will fix.  I see 3 options:

1) Use the numbers like 0x40000005

2) Use QEMU defines like:
     #define CPUID_HV_LEVEL_HYPERV  0x40000005

3) Use condtional define:
     #ifndef HYPERV_CPUID_MIN
     #define CPUID_HV_LEVEL_HYPERV  0x40000005
     #else
     #define CPUID_HV_LEVEL_HYPERV  HYPERV_CPUID_MIN
     #endif

I lean to #2 of #3 and both over #1.  This is because if in the future 
if HYPERV_CPUID_MIN ever changes then a patch to QEMU needs to be done 
and considered before that change can be seen by a guest.  Note: since 
hypervisor-level=0x40000006 can be specified, this might be enough to do 
some testing.

Please advise.

> > +}
> > +
> >   static void x86_get_hv_spinlocks(Object *obj, Visitor *v, void *opaque,
> >                                    const char *name, Error **errp)
> >   {
> > @@ -1214,6 +1221,7 @@ static void x86_set_hv_spinlocks(Object *obj, Visitor *v, 
> > void *opaque,
> >           return;
> >       }
> >       hyperv_set_spinlock_retries(value);
> > +    x86_set_hyperv(obj, errp);
> >   }
> >
> >   static void x86_get_hv_relaxed(Object *obj, Visitor *v, void *opaque,
> > @@ -1234,6 +1242,7 @@ static void x86_set_hv_relaxed(Object *obj, Visitor *v, 
> > void *opaque,
> >           return;
> >       }
> >       hyperv_enable_relaxed_timing(value);
> > +    x86_set_hyperv(obj, errp);
> >   }
> >
> >   static void x86_get_hv_vapic(Object *obj, Visitor *v, void *opaque,
> > @@ -1254,6 +1263,7 @@ static void x86_set_hv_vapic(Object *obj, Visitor *v, 
> > void *opaque,
> >           return;
> >       }
> >       hyperv_enable_vapic_recommended(value);
> > +    x86_set_hyperv(obj, errp);
> >   }
> >   #endif
> >
> > --
> > 1.7.1
   -Don Slutz