x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest

x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest

Latest Intel platform Clearwater Forest has introduced new instructions
enumerated by CPUIDs of SHA512, SM3, SM4 and AVX-VNNI-INT16. Advertise
these CPUIDs to userspace so that guests can query them directly.

SHA512, SM3 and SM4 are on an expected-dense CPUID leaf and some other
bits on this leaf have kernel usages. Considering they have not truly
kernel usages, hide them in /proc/cpuinfo.

These new instructions only operate in xmm, ymm registers and have no new
VMX controls, so there is no additional host enabling required for guests
to use these instructions, i.e. advertising these CPUIDs to userspace is
safe.

Tested-by: Jiaan Lu <jiaan.lu@intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Message-ID: <20241105054825.870939-1-tao1.su@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>