perf/x86/intel: Check perf metrics feature for each CPU
authorKan Liang <kan.liang@linux.intel.com>
Thu, 1 Oct 2020 21:17:11 +0000 (14:17 -0700)
committerPeter Zijlstra <peterz@infradead.org>
Sat, 3 Oct 2020 14:30:56 +0000 (16:30 +0200)
commit80a5ce116fc084e8a25d5a936617699e2931b611
tree20b77a33768ba881e9d9522171b8481263edcb97
parent010cb00265f150bf82b23c02ad1fb87ce5c781e1
perf/x86/intel: Check perf metrics feature for each CPU

It might be possible that different CPUs have different CPU metrics on a
platform. In this case, writing the GLOBAL_CTRL_EN_PERF_METRICS bit to
the GLOBAL_CTRL register of a CPU, which doesn't support the TopDown
perf metrics feature, causes MSR access error.

Current TopDown perf metrics feature is enumerated using the boot CPU's
PERF_CAPABILITIES MSR. The MSR only indicates the boot CPU supports this
feature.

Check the PERF_CAPABILITIES MSR for each CPU. If any CPU doesn't support
the perf metrics feature, disable the feature globally.

Fixes: 59a854e2f3b9 ("perf/x86/intel: Support TopDown metrics on Ice Lake")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001211711.25708-1-kan.liang@linux.intel.com
arch/x86/events/intel/core.c