x86: KVM: Advertise CMPccXADD CPUID to user space
CMPccXADD is a new set of instructions in the latest Intel platform Sierra Forest. This new instruction set includes a semaphore operation that can compare and add the operands if condition is met, which can improve database performance. The bit definition: CPUID.(EAX=7,ECX=1):EAX[bit 7] CMPccXADD is on an expected-dense CPUID leaf and some other bits on this leaf have kernel usages. Given that, define this feature bit like X86_FEATURE_<name> in kernel. Considering CMPccXADD itself has no truly kernel usages and /proc/cpuinfo has too much unreadable flags, hide this one in /proc/cpuinfo. Advertise CMPCCXADD 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: NJiaxi Chen <jiaxi.chen@linux.intel.com> Acked-by: NBorislav Petkov <bp@suse.de> Message-Id: <20221125125845.1182922-4-jiaxi.chen@linux.intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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