• Jiaxi Chen's avatar
    KVM: x86: Advertise AVX-NE-CONVERT CPUID to user space · 9977f087
    Jiaxi Chen authored
    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: default avatarJiaxi Chen <jiaxi.chen@linux.intel.com>
    Message-Id: <20221125125845.1182922-8-jiaxi.chen@linux.intel.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    9977f087
cpuid.c 42.5 KB