perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF

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commit 47a973fd75 upstream.

The EAX of the CPUID Leaf 023H enumerates the mask of valid sub-leaves.
To tell the availability of the sub-leaf 1 (enumerate the counter mask),
perf should check the bit 1 (0x2) of EAS, rather than bit 0 (0x1).

The error is not user-visible on bare metal. Because the sub-leaf 0 and
the sub-leaf 1 are always available. However, it may bring issues in a
virtualization environment when a VMM only enumerates the sub-leaf 0.

Introduce the cpuid35_e?x to replace the macros, which makes the
implementation style consistent.

Fixes: eb467aaac2 ("perf/x86/intel: Support Architectural PerfMon Extension leaf")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250129154820.3755948-3-kan.liang@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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This commit is contained in:

Kan Liang 2025-01-29 07:48:19 -08:00 • committed by Greg Kroah-Hartman

parent 55057ec275

commit aa7a1bee54

2 changed files with 35 additions and 11 deletions

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18

arch/x86/events/intel/core.c

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28

arch/x86/include/asm/perf_event.h

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