[kvm-unit-tests,v4,08/17] x86: pmu: Use macro to replace hard-coded branches event index

Commit Message

Mi, Dapeng April 19, 2024, 3:52 a.m. UTC

Currently the branches event index is a hard-coded number. User could
add new events and cause the branches event index changes in the future,
but don't notice the hard-coded event index and forget to update the
event index synchronously, then the issue comes.

Thus, replace the hard-coded index to a macro.

Signed-off-by: Dapeng Mi <[e-mail]>
---
 x86/pmu.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Patch

diff --git a/x86/pmu.c b/x86/pmu.c
index 43ef7ecbcaea..fd1b22104fc4 100644
--- a/x86/pmu.c
+++ b/x86/pmu.c
@@ -49,6 +49,22 @@  struct pmu_event {
 	{"fixed 2", MSR_CORE_PERF_FIXED_CTR0 + 2, 0.1*N, 30*N}
 };
 
+/*
+ * Events index in intel_gp_events[], ensure consistent with
+ * intel_gp_events[].
+ */
+enum {
+	INTEL_BRANCHES_IDX	= 5,
+};
+
+/*
+ * Events index in amd_gp_events[], ensure consistent with
+ * amd_gp_events[].
+ */
+enum {
+	AMD_BRANCHES_IDX	= 2,
+};
+
 char *buf;
 
 static struct pmu_event *gp_events;
@@ -481,7 +497,8 @@  static void check_emulated_instr(void)
 {
 	uint64_t status, instr_start, brnch_start;
 	uint64_t gp_counter_width = (1ull << pmu.gp_counter_width) - 1;
-	unsigned int branch_idx = pmu.is_intel ? 5 : 2;
+	unsigned int branch_idx = pmu.is_intel ?
+				  INTEL_BRANCHES_IDX : AMD_BRANCHES_IDX;
 	pmu_counter_t brnch_cnt = {
 		.ctr = MSR_GP_COUNTERx(0),
 		/* branch instructions */