[PATCH 3/3] perf/x86/intel: Fix instructions:ppp support in Sapphire Rapids

From: kan . liang
Date: Fri Jun 18 2021 - 11:29:42 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Perf errors out when sampling instructions:ppp.

$ perf record -e instructions:ppp -- true
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument)
for event (instructions:ppp).

The instruction PDIR is only available on the fixed counter 0. The event
constraint has been updated to fixed0_constraint in
icl_get_event_constraints(). The Sapphire Rapids codes unconditionally
error out for the event which is not available on the GP counter 0.

Make the instructions:ppp an exception.

Fixes: 61b985e3e775 ("perf/x86/intel: Add perf core PMU support for Sapphire Rapids")
Reported-by: Yasin, Ahmad <ahmad.yasin@xxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
arch/x86/events/intel/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index e442b55..e355db5 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4032,8 +4032,10 @@ spr_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
* The :ppp indicates the Precise Distribution (PDist) facility, which
* is only supported on the GP counter 0. If a :ppp event which is not
* available on the GP counter 0, error out.
+ * Exception: Instruction PDIR is only available on the fixed counter 0.
*/
- if (event->attr.precise_ip == 3) {
+ if ((event->attr.precise_ip == 3) &&
+ !constraint_match(&fixed0_constraint, event->hw.config)) {
if (c->idxmsk64 & BIT_ULL(0))
return &counter0_constraint;

--
2.7.4