On 12/7/2022 3:15 PM, Like Xu wrote:
From: Like Xu <likexu@xxxxxxxxxxx>
On Intel platforms with TSX feature, pmu users in guest can collect
the commited or total transactional cycles for a tsx-enabled workload,
adding new test cases to cover them, as they are not strictly the same
as normal hardware events from the KVM implementation point of view.
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
---
x86/pmu.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 72 insertions(+), 1 deletion(-)
diff --git a/x86/pmu.c b/x86/pmu.c
index 72c2c9c..d4c6813 100644
--- a/x86/pmu.c
+++ b/x86/pmu.c
@@ -20,7 +20,7 @@
typedef struct {
uint32_t ctr;
- uint32_t config;
+ uint64_t config;
uint64_t count;
int idx;
} pmu_counter_t;
@@ -547,6 +547,76 @@ static void check_emulated_instr(void)
report_prefix_pop();
}
+#define _XBEGIN_STARTED (~0u)
+
+static inline int _xbegin(void)
+{
+ int ret = _XBEGIN_STARTED;
+ asm volatile(".byte 0xc7,0xf8 ; .long 0" : "+a" (ret) :: "memory");
+ return ret;
+}
+
+static inline void _xend(void)
+{
+ asm volatile(".byte 0x0f,0x01,0xd5" ::: "memory");
+}
+
+int *ptr;
+
+static void tsx_fault(void)
+{
+ int value = 0;
+
+ ptr = NULL;
+ if(_xbegin() == _XBEGIN_STARTED) {
+ value++;
+ // causes abort
+ *ptr = value;
+ _xend();
+ }
+}
+
+static void tsx_normal(void)
+{
+ int value = 0;
+
+ if(_xbegin() == _XBEGIN_STARTED) {
+ value++;
+ _xend();
+ }
+}
+
+static void check_tsx_cycles(void)
+{
+ pmu_counter_t cnt;
+ int i;
+
+ if (!this_cpu_has(X86_FEATURE_RTM) || !this_cpu_has(X86_FEATURE_HLE))
+ return;
Since the test case is for xbegin/xend, HLE check may omit as it's for
other X-instructions.
+
+ report_prefix_push("TSX cycles");
+
+ for (i = 0; i < pmu.nr_gp_counters; i++) {
+ cnt.ctr = MSR_GP_COUNTERx(i);
+
+ if (i == 2)
+ /* Transactional cycles commited only on gp counter 2 */
+ cnt.config = EVNTSEL_OS | EVNTSEL_USR | 0x30000003c;
+ else
+ /* Transactional cycles */
+ cnt.config = EVNTSEL_OS | EVNTSEL_USR | 0x10000003c;
+
+ start_event(&cnt);
+ tsx_fault();
+ tsx_normal();
+ stop_event(&cnt);
+
+ report(cnt.count > 0, "gp cntr-%d", i);
The purpose is to collect total cycles, why not print out the data here
for each GP counter?
+ }
+
+ report_prefix_pop();
+}
+
static void check_counters(void)
{
if (is_fep_available())
@@ -559,6 +629,7 @@ static void check_counters(void)
check_counter_overflow();
check_gp_counter_cmask();
check_running_counter_wrmsr();
+ check_tsx_cycles();
}
static void do_unsupported_width_counter_write(void *index)
