KVM: riscv: selftests: Change command line option

The PMU test commandline option takes an argument to disable a
certain test. The initial assumption behind this was a common use case
is just to run all the test most of the time. However, running a single
test seems more useful instead. Especially, the overflow test has been
helpful to validate PMU virtualizaiton interrupt changes.

Switching the command line option to run a single test instead
of disabling a single test also allows to provide additional
test specific arguments to the test. The default without any options
remains unchanged which continues to run all the tests.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20250303-kvm_pmu_improve-v2-3-41d177e45929@rivosinc.com
Signed-off-by: Anup Patel <anup@brainfault.org>

tools/testing/selftests/kvm/riscv/sbi_pmu_test.c

@@ -39,7 +39,11 @@ static bool illegal_handler_invoked;
 #define SBI_PMU_TEST_SNAPSHOT	BIT(2)
 #define SBI_PMU_TEST_OVERFLOW	BIT(3)
 
-static int disabled_tests;
+struct test_args {
+	int disabled_tests;
+};
+
+static struct test_args targs;
 
 unsigned long pmu_csr_read_num(int csr_num)
 {
@@ -604,7 +608,11 @@ static void test_vm_events_overflow(void *guest_code)
 	vcpu_init_vector_tables(vcpu);
 	/* Initialize guest timer frequency. */
 	timer_freq = vcpu_get_reg(vcpu, RISCV_TIMER_REG(frequency));
+
+	/* Export the shared variables to the guest */
 	sync_global_to_guest(vm, timer_freq);
+	sync_global_to_guest(vm, vcpu_shared_irq_count);
+	sync_global_to_guest(vm, targs);
 
 	run_vcpu(vcpu);
 
@@ -613,28 +621,30 @@ static void test_vm_events_overflow(void *guest_code)
 
 static void test_print_help(char *name)
 {
-	pr_info("Usage: %s [-h] [-d <test name>]\n", name);
-	pr_info("\t-d: Test to disable. Available tests are 'basic', 'events', 'snapshot', 'overflow'\n");
+	pr_info("Usage: %s [-h] [-t <test name>]\n", name);
+	pr_info("\t-t: Test to run (default all). Available tests are 'basic', 'events', 'snapshot', 'overflow'\n");
 	pr_info("\t-h: print this help screen\n");
 }
 
 static bool parse_args(int argc, char *argv[])
 {
 	int opt;
-
-	while ((opt = getopt(argc, argv, "hd:")) != -1) {
+	int temp_disabled_tests = SBI_PMU_TEST_BASIC | SBI_PMU_TEST_EVENTS | SBI_PMU_TEST_SNAPSHOT |
+				  SBI_PMU_TEST_OVERFLOW;
+	while ((opt = getopt(argc, argv, "ht:")) != -1) {
 		switch (opt) {
-		case 'd':
+		case 't':
 			if (!strncmp("basic", optarg, 5))
-				disabled_tests |= SBI_PMU_TEST_BASIC;
+				temp_disabled_tests &= ~SBI_PMU_TEST_BASIC;
 			else if (!strncmp("events", optarg, 6))
-				disabled_tests |= SBI_PMU_TEST_EVENTS;
+				temp_disabled_tests &= ~SBI_PMU_TEST_EVENTS;
 			else if (!strncmp("snapshot", optarg, 8))
-				disabled_tests |= SBI_PMU_TEST_SNAPSHOT;
+				temp_disabled_tests &= ~SBI_PMU_TEST_SNAPSHOT;
 			else if (!strncmp("overflow", optarg, 8))
-				disabled_tests |= SBI_PMU_TEST_OVERFLOW;
+				temp_disabled_tests &= ~SBI_PMU_TEST_OVERFLOW;
 			else
 				goto done;
+			targs.disabled_tests = temp_disabled_tests;
 			break;
 		case 'h':
 		default:
@@ -650,25 +660,27 @@ static bool parse_args(int argc, char *argv[])
 
 int main(int argc, char *argv[])
 {
+	targs.disabled_tests = 0;
+
 	if (!parse_args(argc, argv))
 		exit(KSFT_SKIP);
 
-	if (!(disabled_tests & SBI_PMU_TEST_BASIC)) {
+	if (!(targs.disabled_tests & SBI_PMU_TEST_BASIC)) {
 		test_vm_basic_test(test_pmu_basic_sanity);
 		pr_info("SBI PMU basic test : PASS\n");
 	}
 
-	if (!(disabled_tests & SBI_PMU_TEST_EVENTS)) {
+	if (!(targs.disabled_tests & SBI_PMU_TEST_EVENTS)) {
 		test_vm_events_test(test_pmu_events);
 		pr_info("SBI PMU event verification test : PASS\n");
 	}
 
-	if (!(disabled_tests & SBI_PMU_TEST_SNAPSHOT)) {
+	if (!(targs.disabled_tests & SBI_PMU_TEST_SNAPSHOT)) {
 		test_vm_events_snapshot_test(test_pmu_events_snaphost);
 		pr_info("SBI PMU event verification with snapshot test : PASS\n");
 	}
 
-	if (!(disabled_tests & SBI_PMU_TEST_OVERFLOW)) {
+	if (!(targs.disabled_tests & SBI_PMU_TEST_OVERFLOW)) {
 		test_vm_events_overflow(test_pmu_events_overflow);
 		pr_info("SBI PMU event verification with overflow test : PASS\n");
 	}