Re: [Qemu-devel] [PATCH] x86: Fix Opteron xlevels

[Alexander Graf]

On 04/21/2015 04:16 PM, Eduardo Habkost wrote:
> On Tue, Apr 21, 2015 at 04:04:21PM +0200, Alexander Graf wrote:
> > The AMD Opteron family has different xlevel levels depending on the
> > generation. I looked up Gen1, Gen2 and Gen3 hardware and adapted the
> > levels according to real silicon.
> >
> > The reason this came up is that there is a sanity check in KVM making
> > sure that SVM is only used when xlevel is high enough. Using real
> > hardware levels, they now are.
> >
> > Reported-by: Bernhard M. Wiedemann <address@hidden>
> > Signed-off-by: Alexander Graf <address@hidden>
> It needs compatibility properties in HW_COMPAT_2_1.  See commit
> 6b11322e0f724eb0649fdc324a44288b783023ad for reference.

Ah, sure, will do.

> > ---
> >   target-i386/cpu.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 03b33cf..d1b1b8c 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -1234,7 +1234,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> >               CPUID_EXT2_MTRR | CPUID_EXT2_SYSCALL | CPUID_EXT2_APIC |
> >               CPUID_EXT2_CX8 | CPUID_EXT2_MCE | CPUID_EXT2_PAE | CPUID_EXT2_MSR 
> > |
> >               CPUID_EXT2_TSC | CPUID_EXT2_PSE | CPUID_EXT2_DE | CPUID_EXT2_FPU,
> > -        .xlevel = 0x80000008,
> > +        .xlevel = 0x80000018,
> Why did you choose 0x80000018? The highest 0x80000000 leaf we implement
> today is 0x8000000A. SVM info is at 0x8000000A.

Because it's what real hardware exposes ;).


Alex

> >           .model_id = "AMD Opteron 240 (Gen 1 Class Opteron)",
> >       },
> >       {
> > @@ -1262,7 +1262,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> >               CPUID_EXT2_DE | CPUID_EXT2_FPU,
> >           .features[FEAT_8000_0001_ECX] =
> >               CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
> > -        .xlevel = 0x80000008,
> > +        .xlevel = 0x80000018,
> >           .model_id = "AMD Opteron 22xx (Gen 2 Class Opteron)",
> >       },
> >       {
> > @@ -1292,7 +1292,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> >           .features[FEAT_8000_0001_ECX] =
> >               CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A |
> >               CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
> > -        .xlevel = 0x80000008,
> > +        .xlevel = 0x8000001A,
> >           .model_id = "AMD Opteron 23xx (Gen 3 Class Opteron)",
> >       },
> >       {
> > --
> > 1.7.12.4