diff options
| author | Jiaxi Chen <[email protected]> | 2022-11-25 20:58:42 +0800 |
|---|---|---|
| committer | Paolo Bonzini <[email protected]> | 2022-11-28 13:33:28 -0500 |
| commit | 5e85c4ebf206e50c58e82ca44c15e2be2bac6923 (patch) | |
| tree | eea7adac6a5aa734baa8ae629ec425e14c08f0ce /lib/mpi/mpi-sub-ui.c | |
| parent | af2872f6225476566bcbbd523a74dcaba29e159e (diff) | |
x86: KVM: Advertise AVX-IFMA CPUID to user space
AVX-IFMA is a new instruction in the latest Intel platform Sierra
Forest. This instruction packed multiplies unsigned 52-bit integers and
adds the low/high 52-bit products to Qword Accumulators.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 23]
AVX-IFMA 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 AVX-IFMA itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise AVX-IFMA 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 <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Diffstat (limited to 'lib/mpi/mpi-sub-ui.c')
0 files changed, 0 insertions, 0 deletions