perf/x86: Honor the architectural performance monitoring version

commit 2c33645d366d13b969d936b68b9f4875b1fdddea upstream.

Architectural performance monitoring, version 1, doesn't support fixed counters.

Currently, even if a hypervisor advertises support for architectural
performance monitoring version 1, perf may still try to use the fixed
counters, as the constraints are set up based on the CPU model.

This patch ensures that perf honors the architectural performance monitoring
version returned by CPUID, and it only uses the fixed counters for version 2
and above.

(Some of the ideas in this patch came from Peter Zijlstra.)

Signed-off-by: Imre Palik <imrep@amazon.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433767609-1039-1-git-send-email-imrep.amz@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[wt: FIXED_EVENT_FLAGS was X86_RAW_EVENT_MASK in 3.10]
Cc: Kevin Christopher <kevinc@vmware.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index ac057583282a933f2de6add19ef572eec43a40ab..bfc6bb5ac65413cd3a53e1a2049fb98c29420d2d 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2241,13 +2241,16 @@ __init int intel_pmu_init(void)
                 * counter, so do not extend mask to generic counters
                 */
                for_each_event_constraint(c, x86_pmu.event_constraints) {
-                       if (c->cmask != X86_RAW_EVENT_MASK
-                           || c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) {
+                       if (c->cmask == X86_RAW_EVENT_MASK
+                           && c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) {
+                               c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1;
                                continue;
                        }
 
-                       c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1;
-                       c->weight += x86_pmu.num_counters;
+                       c->idxmsk64 &=
+                               ~(~0UL << (INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed));
+                       c->weight = hweight64(c->idxmsk64);
+
                }
        }