diff mbox series

[v12,06/17] x86/perf/core: Add pebs_capable to store valid PEBS_COUNTER_MASK value

Message ID 20220304090427.90888-7-likexu@tencent.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86/pmu: Add *basic* support to enable guest PEBS via DS | expand

Commit Message

Like Xu March 4, 2022, 9:04 a.m. UTC
From: "Peter Zijlstra (Intel)" <peterz@infradead.org>

The value of pebs_counter_mask will be accessed frequently
for repeated use in the intel_guest_get_msrs(). So it can be
optimized instead of endlessly mucking about with branches.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/events/intel/core.c | 14 ++++++--------
 arch/x86/events/perf_event.h |  1 +
 2 files changed, 7 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 820f9fb9339b..7f0bab2f70fd 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2911,10 +2911,7 @@  static int handle_pmi_common(struct pt_regs *regs, u64 status)
 	 * counters from the GLOBAL_STATUS mask and we always process PEBS
 	 * events via drain_pebs().
 	 */
-	if (x86_pmu.flags & PMU_FL_PEBS_ALL)
-		status &= ~cpuc->pebs_enabled;
-	else
-		status &= ~(cpuc->pebs_enabled & PEBS_COUNTER_MASK);
+	status &= ~(cpuc->pebs_enabled & x86_pmu.pebs_capable);
 
 	/*
 	 * PEBS overflow sets bit 62 in the global status register
@@ -3960,10 +3957,7 @@  static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
 	arr[0].msr = MSR_CORE_PERF_GLOBAL_CTRL;
 	arr[0].host = intel_ctrl & ~cpuc->intel_ctrl_guest_mask;
 	arr[0].guest = intel_ctrl & ~cpuc->intel_ctrl_host_mask;
-	if (x86_pmu.flags & PMU_FL_PEBS_ALL)
-		arr[0].guest &= ~cpuc->pebs_enabled;
-	else
-		arr[0].guest &= ~(cpuc->pebs_enabled & PEBS_COUNTER_MASK);
+	arr[0].guest &= ~(cpuc->pebs_enabled & x86_pmu.pebs_capable);
 	*nr = 1;
 
 	if (x86_pmu.pebs && x86_pmu.pebs_no_isolation) {
@@ -5667,6 +5661,7 @@  __init int intel_pmu_init(void)
 	x86_pmu.events_mask_len		= eax.split.mask_length;
 
 	x86_pmu.max_pebs_events		= min_t(unsigned, MAX_PEBS_EVENTS, x86_pmu.num_counters);
+	x86_pmu.pebs_capable		= PEBS_COUNTER_MASK;
 
 	/*
 	 * Quirk: v2 perfmon does not report fixed-purpose events, so
@@ -5851,6 +5846,7 @@  __init int intel_pmu_init(void)
 		x86_pmu.pebs_aliases = NULL;
 		x86_pmu.pebs_prec_dist = true;
 		x86_pmu.lbr_pt_coexist = true;
+		x86_pmu.pebs_capable = ~0ULL;
 		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
 		x86_pmu.flags |= PMU_FL_PEBS_ALL;
 		x86_pmu.get_event_constraints = glp_get_event_constraints;
@@ -6208,6 +6204,7 @@  __init int intel_pmu_init(void)
 		x86_pmu.pebs_aliases = NULL;
 		x86_pmu.pebs_prec_dist = true;
 		x86_pmu.pebs_block = true;
+		x86_pmu.pebs_capable = ~0ULL;
 		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
 		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
 		x86_pmu.flags |= PMU_FL_PEBS_ALL;
@@ -6250,6 +6247,7 @@  __init int intel_pmu_init(void)
 		x86_pmu.pebs_aliases = NULL;
 		x86_pmu.pebs_prec_dist = true;
 		x86_pmu.pebs_block = true;
+		x86_pmu.pebs_capable = ~0ULL;
 		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
 		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
 		x86_pmu.flags |= PMU_FL_PEBS_ALL;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index bf23cbe4f6cf..9e1bef9c2b0c 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -825,6 +825,7 @@  struct x86_pmu {
 	void		(*pebs_aliases)(struct perf_event *event);
 	unsigned long	large_pebs_flags;
 	u64		rtm_abort_event;
+	u64		pebs_capable;
 
 	/*
 	 * Intel LBR