Re: [PATCH 1/6] target/i386: Add AVX512 state when AVX10 is supported

[Tao Su <tao1.su@linux.intel.com>]

On Mon, Oct 28, 2024 at 09:41:14AM +0100, Paolo Bonzini wrote:
> On 10/28/24 03:45, Tao Su wrote:
> > AVX10 state enumeration in CPUID leaf D and enabling in XCR0 register
> > are identical to AVX512 state regardless of the supported vector lengths.
> > 
> > Given that some E-cores will support AVX10 but not support AVX512, add
> > AVX512 state components to guest when AVX10 is enabled.
> > 
> > Tested-by: Xuelian Guo <xuelian.guo@intel.com>
> > Signed-off-by: Tao Su <tao1.su@linux.intel.com>
> > ---
> >   target/i386/cpu.c | 14 ++++++++++++++
> >   target/i386/cpu.h |  2 ++
> >   2 files changed, 16 insertions(+)
> > 
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index 1ff1af032e..d845ff5e4e 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -7177,6 +7177,13 @@ static void x86_cpu_reset_hold(Object *obj, ResetType type)
> >           }
> >           if (env->features[esa->feature] & esa->bits) {
> >               xcr0 |= 1ull << i;
> > +            continue;
> > +        }
> > +        if (i == XSTATE_OPMASK_BIT || i == XSTATE_ZMM_Hi256_BIT ||
> > +            i == XSTATE_Hi16_ZMM_BIT) {
> 
> Can you confirm that XSTATE_ZMM_Hi256_BIT depends on AVX10 and not
> AVX10-512?
> 

Sorry, I should attach AVX10.2 spec [*].

In 3.1.3, spec said Intel AVX10 state enumeration in CPUID leaf 0xD and
enabling in XCR0 register are identical to Intel AVX-512 regardless of the
maximum vector length supported.

So XSTATE_ZMM_Hi256_BIT doesn't depend on AVX10-512.

[*] https://cdrdv2.intel.com/v1/dl/getContent/828965