[PATCH] perf/x86/vlbr: Add c->flags to vlbr event constraints
From: Like Xu <hidden>
Date: 2021-11-03 09:17:28
Also in:
lkml
Subsystem:
performance events subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen
From: Like Xu <redacted>
Just like what we do in the x86_get_event_constraints(), the
PERF_X86_EVENT_LBR_SELECT flag should also be propagated
to event->hw.flags so that the host lbr driver can save/restore
MSR_LBR_SELECT for the special vlbr event created by KVM or BPF.
Reported-by: Wanpeng Li <redacted>
Fixes: 097e4311cda9 ("perf/x86: Add constraint to create guest LBR event without hw counter")
Signed-off-by: Like Xu <redacted>
---
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 7011e87be6d0..30b5d1b3cb03 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c@@ -2997,8 +2997,10 @@ intel_vlbr_constraints(struct perf_event *event) { struct event_constraint *c = &vlbr_constraint; - if (unlikely(constraint_match(c, event->hw.config))) + if (unlikely(constraint_match(c, event->hw.config))) { + event->hw.flags |= c->flags; return c; + } return NULL; }
--
2.33.0