On 11/19/2022 1:17 AM, Sean Christopherson wrote: > On Fri, Nov 18, 2022, Jiaxi Chen wrote: >> AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform >> Sierra Forest, aims for the platform to have superior AI capabilities. >> This instruction multiplies the individual bytes of two unsigned or >> unsigned source operands, then adds and accumulates the results into the >> destination dword element size operand. >> >> The bit definition: >> CPUID.(EAX=7,ECX=1):EDX[bit 4] >> >> This CPUID is exposed to user space. Besides, there is no other VMX >> control for this instruction. >> >> Signed-off-by: Jiaxi Chen <jiaxi.chen@xxxxxxxxxxxxxxx> >> --- >> arch/x86/kvm/cpuid.c | 5 ++++- >> arch/x86/kvm/reverse_cpuid.h | 5 +++++ >> 2 files changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >> index 5726afb2d14c..e2b8e5485474 100644 >> --- a/arch/x86/kvm/cpuid.c >> +++ b/arch/x86/kvm/cpuid.c >> @@ -660,6 +660,9 @@ void kvm_set_cpu_caps(void) >> F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) | >> F(AVX_IFMA)); >> >> + kvm_cpu_cap_init_scattered(CPUID_7_1_EDX, > > Ah, this is going to be confusing and potentially error prone. AVX_VNNI_INT8 > isn't actually scattered, i.e. kvm_cpu_cap_init_scattered() is poorly named. And > using SF() would be _really_ broken as boot_cpu_has() would consume garbage and > potentially leak kernel state to userspace. > > To address these issue and also document how to add KVM-only features, can you > slot in the two attached patches at the begining of this series? > Sure. Thanks for your kind contribution. > Thanks! > >> + F(AVX_VNNI_INT8)); > > Terminators on a separate line please. > >> kvm_cpu_cap_mask(CPUID_D_1_EAX, >> F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) | f_xfd >> ); Got it. Thanks~ -- Regards, Jiaxi
