From 0d0b60865071115f6da76090f0dbc1f0e8b9c647 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 6 Mar 2024 17:13:43 -0800 Subject: perf/x86/intel: Expose existence of callback support to KVM Add a "has_callstack" field to the x86_pmu_lbr structure used to pass information to KVM, and set it accordingly in x86_perf_get_lbr(). KVM will use has_callstack to avoid trying to create perf LBR events with PERF_SAMPLE_BRANCH_CALL_STACK on CPUs that don't support callstacks. Reviewed-by: Mingwei Zhang Link: https://lore.kernel.org/r/20240307011344.835640-3-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/events/intel/lbr.c | 1 + arch/x86/include/asm/perf_event.h | 1 + 2 files changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 78cd5084104e9..4367aa77cb8d9 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1693,6 +1693,7 @@ void x86_perf_get_lbr(struct x86_pmu_lbr *lbr) lbr->from = x86_pmu.lbr_from; lbr->to = x86_pmu.lbr_to; lbr->info = x86_pmu.lbr_info; + lbr->has_callstack = x86_pmu_has_lbr_callstack(); } EXPORT_SYMBOL_GPL(x86_perf_get_lbr); diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 3736b8a46c04d..7f1e17250546b 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -555,6 +555,7 @@ struct x86_pmu_lbr { unsigned int from; unsigned int to; unsigned int info; + bool has_callstack; }; extern void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap); -- cgit 1.2.3-korg