Re: [PATCH 4/4] KVM: riscv: selftests: Allow number of interrupts to be configurable

On Wed, Feb 26, 2025 at 12:25:06PM -0800, Atish Patra wrote:

It is helpful to vary the number of the LCOFI interrupts generated by the overflow test. Allow additional argument for overflow test to accommodate that. It can be easily cross-validated with /proc/interrupts output in the host.

Signed-off-by: Atish Patra atishp@rivosinc.com

tools/testing/selftests/kvm/riscv/sbi_pmu_test.c | 36 ++++++++++++++++++++---- 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c index 533b76d0de82..7c273a1adb17 100644 --- a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c @@ -39,8 +39,10 @@ static bool illegal_handler_invoked; #define SBI_PMU_TEST_SNAPSHOT BIT(2) #define SBI_PMU_TEST_OVERFLOW BIT(3) +#define SBI_PMU_OVERFLOW_IRQNUM_DEFAULT 5 struct test_args { int disabled_tests;

• int overflow_irqnum;

}; static struct test_args targs; @@ -478,7 +480,7 @@ static void test_pmu_events_snaphost(void) static void test_pmu_events_overflow(void) {

• int num_counters = 0;

• int num_counters = 0, i = 0;

/* Verify presence of SBI PMU and minimum requrired SBI version */ verify_sbi_requirement_assert(); @@ -495,11 +497,15 @@ static void test_pmu_events_overflow(void) * Qemu supports overflow for cycle/instruction. * This test may fail on any platform that do not support overflow for these two events. */

• test_pmu_event_overflow(SBI_PMU_HW_CPU_CYCLES);
• GUEST_ASSERT_EQ(vcpu_shared_irq_count, 1);

• for (i = 0; i < targs.overflow_irqnum; i++)

• test_pmu_event_overflow(SBI_PMU_HW_CPU_CYCLES);
  

• GUEST_ASSERT_EQ(vcpu_shared_irq_count, targs.overflow_irqnum);
• vcpu_shared_irq_count = 0;

• test_pmu_event_overflow(SBI_PMU_HW_INSTRUCTIONS);
• GUEST_ASSERT_EQ(vcpu_shared_irq_count, 2);

• for (i = 0; i < targs.overflow_irqnum; i++)

• test_pmu_event_overflow(SBI_PMU_HW_INSTRUCTIONS);
  

• GUEST_ASSERT_EQ(vcpu_shared_irq_count, targs.overflow_irqnum);

GUEST_DONE(); } @@ -621,8 +627,11 @@ static void test_vm_events_overflow(void *guest_code) static void test_print_help(char *name) {

• pr_info("Usage: %s [-h] [-t <test name>]\n", name);

• pr_info("Usage: %s [-h] [-t <test name>] [-n <number of LCOFI interrupt for overflow test>]\n",

• name);
  

  pr_info("\t-t: Test to run (default all). Available tests are 'basic', 'events', 'snapshot', 'overflow'\n");
• pr_info("\t-n: Number of LCOFI interrupt to trigger for each event in overflow test (default: %d)\n",

• SBI_PMU_OVERFLOW_IRQNUM_DEFAULT);
  

  pr_info("\t-h: print this help screen\n");

} @@ -631,6 +640,8 @@ static bool parse_args(int argc, char *argv[]) int opt; int temp_disabled_tests = SBI_PMU_TEST_BASIC | SBI_PMU_TEST_EVENTS | SBI_PMU_TEST_SNAPSHOT | SBI_PMU_TEST_OVERFLOW;

• int overflow_interrupts = -1;

Initializing to -1 made me think that '-n 0' would be valid and a way to disable the overflow test, but...

• while ((opt = getopt(argc, argv, "h:t:n:")) != -1) { switch (opt) { case 't':

@@ -646,12 +657,24 @@ static bool parse_args(int argc, char *argv[]) goto done; targs.disabled_tests = temp_disabled_tests; break;

• case 'n':
  

• 	overflow_interrupts = atoi_positive("Number of LCOFI", optarg);
  

...here we use atoi_positive() and...

• 	break;
  

  case 'h': default: goto done; } }

• if (overflow_interrupts > 0) {

...here we only change from the default of 5 for nonzero.

Should we allow '-n 0'? Otherwise overflow_interrupts can be initialized to zero (not that it matters).

• if (targs.disabled_tests & SBI_PMU_TEST_OVERFLOW) {
  

• 	pr_info("-n option is only available for overflow test\n");
  

• 	goto done;
  

• } else {
  

• 	targs.overflow_irqnum = overflow_interrupts;
  

• }
  

• }
• return true;

done: test_print_help(argv[0]); @@ -661,6 +684,7 @@ static bool parse_args(int argc, char *argv[]) int main(int argc, char *argv[]) { targs.disabled_tests = 0;

• targs.overflow_irqnum = SBI_PMU_OVERFLOW_IRQNUM_DEFAULT;

if (!parse_args(argc, argv)) exit(KSFT_SKIP);

-- 2.43.0

Thanks, drew