KVM: x86: Advertise AVX-NE-CONVERT CPUID to user space

AVX-NE-CONVERT is a new set of instructions which can convert low
precision floating point like BF16/FP16 to high precision floating point
FP32, and can also convert FP32 elements to BF16. This instruction
allows the platform to have improved AI capabilities and better
compatibility.

The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 5]

AVX-NE-CONVERT is on a KVM-only subleaf. Plus an x86_FEATURE definition
for this feature bit to direct it to the KVM entry.

Advertise AVX-NE-CONVERT to KVM userspace. This is safe because there
are no new VMX controls or additional host enabling required for guests
to use this feature.

Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Message-Id: <20221125125845.1182922-8-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Jiaxi Chen 2022-11-25 20:58:44 +08:00 • committed by Paolo Bonzini
commit 9977f0877d
2 changed files with 2 additions and 1 deletions