KVM: x86: Advertise and enable LAM (user and supervisor)
authorRobert Hoo <robert.hu@linux.intel.com>
Wed, 13 Sep 2023 12:42:23 +0000 (20:42 +0800)
committerSean Christopherson <seanjc@google.com>
Wed, 29 Nov 2023 01:54:09 +0000 (17:54 -0800)
LAM is enumerated by CPUID.7.1:EAX.LAM[bit 26]. Advertise the feature to
userspace and enable it as the final step after the LAM virtualization
support for supervisor and user pointers.

SGX LAM support is not advertised yet. SGX LAM support is enumerated in
SGX's own CPUID and there's no hard requirement that it must be supported
when LAM is reported in CPUID leaf 0x7.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Link: https://lore.kernel.org/r/20230913124227.12574-13-binbin.wu@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
arch/x86/kvm/cpuid.c

index dda6fc4..40d68fe 100644 (file)
@@ -671,7 +671,7 @@ void kvm_set_cpu_caps(void)
        kvm_cpu_cap_mask(CPUID_7_1_EAX,
                F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) |
                F(FZRM) | F(FSRS) | F(FSRC) |
-               F(AMX_FP16) | F(AVX_IFMA)
+               F(AMX_FP16) | F(AVX_IFMA) | F(LAM)
        );
 
        kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,