KVM: x86: Advertise PREFETCHIT0/1 CPUID to user space

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Latest Intel platform Granite Rapids has introduced a new instruction -
PREFETCHIT0/1, which moves code to memory (cache) closer to the
processor depending on specific hints.

The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 14]

PREFETCHIT0/1 is on a KVM-only subleaf. Plus an x86_FEATURE definition
for this feature bit to direct it to the KVM entry.

Advertise PREFETCHIT0/1 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: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Message-Id: <20221125125845.1182922-9-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...

This commit is contained in:

Jiaxi Chen 2022-11-25 20:58:45 +08:00 • committed by Paolo Bonzini

parent 9977f0877d

commit 29c46979b2

2 changed files with 2 additions and 1 deletions

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2

arch/x86/kvm/cpuid.c

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1

arch/x86/kvm/reverse_cpuid.h

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