KVM: x86: Advertise and enable LAM (user and supervisor)

Upstream commit: 703d794
Conflict: none

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.

Intel-SIG: commit 703d794 KVM: x86: Advertise and enable LAM (user
and supervisor)
Backport KVM Linear Address Masking (LAM) support.

Signed-off-by: Robert Hoo <[email protected]>
Signed-off-by: Binbin Wu <[email protected]>
Reviewed-by: Jingqi Liu <[email protected]>
Reviewed-by: Chao Gao <[email protected]>
Reviewed-by: Kai Huang <[email protected]>
Tested-by: Xuelian Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[ Zhiquan Li: amend commit log ]
Signed-off-by: Zhiquan Li <[email protected]>

arch/x86/kvm/cpuid.c

@@ -670,7 +670,7 @@ 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,