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
[ The patch is not exactly the same as the upstream patch. Because in the 6.6
stable kernel, the umask2/eq enumeration is not supported. The number of
counters is used rather than the counter mask. But the change is
straightforward, which utilizes the structured union to replace the macros
when parsing the CPUID enumeration. It also fixed a wrong macros. ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ad75c8ef50