2024-04-19 03:48:57

by Mi, Dapeng

Subject: [kvm-unit-tests Patch v4 10/17] x86: pmu: Use macro to replace hard-coded instructions event index

Replace hard-coded instruction event index with macro to avoid possible
mismatch issue if new event is added in the future and cause
instructions event index changed, but forget to update the hard-coded
event index.

Signed-off-by: Dapeng Mi <[email protected]>
---
x86/pmu.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/x86/pmu.c b/x86/pmu.c
index 6ae46398d84b..20bc6de9c936 100644
--- a/x86/pmu.c
+++ b/x86/pmu.c
@@ -54,6 +54,7 @@ struct pmu_event {
* intel_gp_events[].
*/
enum {
+ INTEL_INSTRUCTIONS_IDX = 1,
INTEL_REF_CYCLES_IDX = 2,
INTEL_BRANCHES_IDX = 5,
};
@@ -63,6 +64,7 @@ enum {
* amd_gp_events[].
*/
enum {
+ AMD_INSTRUCTIONS_IDX = 1,
AMD_BRANCHES_IDX = 2,
};

@@ -317,11 +319,16 @@ static uint64_t measure_for_overflow(pmu_counter_t *cnt)

static void check_counter_overflow(void)
{
- uint64_t overflow_preset;
int i;
+ uint64_t overflow_preset;
+ int instruction_idx = pmu.is_intel ?
+ INTEL_INSTRUCTIONS_IDX :
+ AMD_INSTRUCTIONS_IDX;
+
pmu_counter_t cnt = {
.ctr = MSR_GP_COUNTERx(0),
- .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel /* instructions */,
+ .config = EVNTSEL_OS | EVNTSEL_USR |
+ gp_events[instruction_idx].unit_sel /* instructions */,
};
overflow_preset = measure_for_overflow(&cnt);

@@ -377,13 +384,18 @@ static void check_counter_overflow(void)

static void check_gp_counter_cmask(void)
{
+ int instruction_idx = pmu.is_intel ?
+ INTEL_INSTRUCTIONS_IDX :
+ AMD_INSTRUCTIONS_IDX;
+
pmu_counter_t cnt = {
.ctr = MSR_GP_COUNTERx(0),
- .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel /* instructions */,
+ .config = EVNTSEL_OS | EVNTSEL_USR |
+ gp_events[instruction_idx].unit_sel /* instructions */,
};
cnt.config |= (0x2 << EVNTSEL_CMASK_SHIFT);
measure_one(&cnt);
- report(cnt.count < gp_events[1].min, "cmask");
+ report(cnt.count < gp_events[instruction_idx].min, "cmask");
}

static void do_rdpmc_fast(void *ptr)
@@ -458,9 +470,14 @@ static void check_running_counter_wrmsr(void)
{
uint64_t status;
uint64_t count;
+ unsigned int instruction_idx = pmu.is_intel ?
+ INTEL_INSTRUCTIONS_IDX :
+ AMD_INSTRUCTIONS_IDX;
+
pmu_counter_t evt = {
.ctr = MSR_GP_COUNTERx(0),
- .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel,
+ .config = EVNTSEL_OS | EVNTSEL_USR |
+ gp_events[instruction_idx].unit_sel,
};

report_prefix_push("running counter wrmsr");
@@ -469,7 +486,7 @@ static void check_running_counter_wrmsr(void)
loop();
wrmsr(MSR_GP_COUNTERx(0), 0);
stop_event(&evt);
- report(evt.count < gp_events[1].min, "cntr");
+ report(evt.count < gp_events[instruction_idx].min, "cntr");

/* clear status before overflow test */
if (this_cpu_has_perf_global_status())
@@ -500,6 +517,9 @@ static void check_emulated_instr(void)
uint64_t gp_counter_width = (1ull << pmu.gp_counter_width) - 1;
unsigned int branch_idx = pmu.is_intel ?
INTEL_BRANCHES_IDX : AMD_BRANCHES_IDX;
+ unsigned int instruction_idx = pmu.is_intel ?
+ INTEL_INSTRUCTIONS_IDX :
+ AMD_INSTRUCTIONS_IDX;
pmu_counter_t brnch_cnt = {
.ctr = MSR_GP_COUNTERx(0),
/* branch instructions */
@@ -508,7 +528,7 @@ static void check_emulated_instr(void)
pmu_counter_t instr_cnt = {
.ctr = MSR_GP_COUNTERx(1),
/* instructions */
- .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel,
+ .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[instruction_idx].unit_sel,
};
report_prefix_push("emulated instruction");

--
2.34.1