Merge tag 'kvm-riscv-6.15-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv changes for 6.15

- Disable the kernel perf counter during configure
- KVM selftests improvements for PMU
- Fix warning at the time of KVM module removal

Author: bonzini

arch/riscv/kvm/main.c

@@ -172,8 +172,8 @@ module_init(riscv_kvm_init);
 
 static void __exit riscv_kvm_exit(void)
 {
-	kvm_riscv_teardown();
-
 	kvm_exit();
+
+	kvm_riscv_teardown();
 }
 module_exit(riscv_kvm_exit);

arch/riscv/kvm/vcpu_onereg.c

@@ -203,7 +203,7 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 	case KVM_RISCV_ISA_EXT_SVADE:
 		/*
 		 * The henvcfg.ADUE is read-only zero if menvcfg.ADUE is zero.
-		 * Svade is not allowed to disable when the platform use Svade.
+		 * Svade can't be disabled unless we support Svadu.
 		 */
 		return arch_has_hw_pte_young();
 	default:

arch/riscv/kvm/vcpu_pmu.c

@@ -666,6 +666,7 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba
 		.type = etype,
 		.size = sizeof(struct perf_event_attr),
 		.pinned = true,
+		.disabled = true,
 		/*
 		 * It should never reach here if the platform doesn't support the sscofpmf
 		 * extension as mode filtering won't work without it.

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

@@ -39,7 +39,13 @@ static bool illegal_handler_invoked;
 #define SBI_PMU_TEST_SNAPSHOT	BIT(2)
 #define SBI_PMU_TEST_OVERFLOW	BIT(3)
 
-static int disabled_tests;
+#define SBI_PMU_OVERFLOW_IRQNUM_DEFAULT 5
+struct test_args {
+	int disabled_tests;
+	int overflow_irqnum;
+};
+
+static struct test_args targs;
 
 unsigned long pmu_csr_read_num(int csr_num)
 {
@@ -118,8 +124,8 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)
 
 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, counter, 1, stop_flags,
 			0, 0, 0);
-	__GUEST_ASSERT(ret.error == 0, "Unable to stop counter %ld error %ld\n",
-			       counter, ret.error);
+	__GUEST_ASSERT(ret.error == 0 || ret.error == SBI_ERR_ALREADY_STOPPED,
+		       "Unable to stop counter %ld error %ld\n", counter, ret.error);
 }
 
 static void guest_illegal_exception_handler(struct ex_regs *regs)
@@ -137,7 +143,6 @@ static void guest_irq_handler(struct ex_regs *regs)
 	unsigned int irq_num = regs->cause & ~CAUSE_IRQ_FLAG;
 	struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
 	unsigned long overflown_mask;
-	unsigned long counter_val = 0;
 
 	/* Validate that we are in the correct irq handler */
 	GUEST_ASSERT_EQ(irq_num, IRQ_PMU_OVF);
@@ -151,10 +156,6 @@ static void guest_irq_handler(struct ex_regs *regs)
 	GUEST_ASSERT(overflown_mask & 0x01);
 
 	WRITE_ONCE(vcpu_shared_irq_count, vcpu_shared_irq_count+1);
-
-	counter_val = READ_ONCE(snapshot_data->ctr_values[0]);
-	/* Now start the counter to mimick the real driver behavior */
-	start_counter(counter_in_use, SBI_PMU_START_FLAG_SET_INIT_VALUE, counter_val);
 }
 
 static unsigned long get_counter_index(unsigned long cbase, unsigned long cmask,
@@ -479,7 +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();
@@ -496,11 +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();
 }
@@ -609,7 +614,11 @@ 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);
 
@@ -618,35 +627,54 @@ 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 <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");
 }
 
 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 = 0;
 
-	while ((opt = getopt(argc, argv, "hd:")) != -1) {
+	while ((opt = getopt(argc, argv, "ht:n:")) != -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 'n':
+			overflow_interrupts = atoi_positive("Number of LCOFI", optarg);
 			break;
 		case 'h':
 		default:
 			goto done;
 		}
 	}
 
+	if (overflow_interrupts > 0) {
+		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]);
@@ -655,25 +683,28 @@ 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);
 
-	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");
 	}