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| author | Jiaxi Chen <jiaxi.chen@linux.intel.com> | 2022-11-25 20:58:40 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-11-28 13:33:27 -0500 |
| commit | 6a19d7aa5821522eec528fd44f24fe774b875377 (patch) | |
| tree | 3fa3bf05fb75c98855d613a8cdd9cf47f511d6de /tools/perf/util/scripting-engines/trace-event-python.c | |
| parent | 047c7229906152fb85c23dc18fd25a00cd7cb4de (diff) | |
| download | linux-6a19d7aa5821522eec528fd44f24fe774b875377.tar.gz linux-6a19d7aa5821522eec528fd44f24fe774b875377.tar.bz2 linux-6a19d7aa5821522eec528fd44f24fe774b875377.zip | |
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: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <20221125125845.1182922-4-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools/perf/util/scripting-engines/trace-event-python.c')
0 files changed, 0 insertions, 0 deletions