KVM: arm64: selftests: Introduce arch_timer selftest

Add a KVM selftest to validate the arch_timer functionality. Primarily, the test sets up periodic timer interrupts and validates the basic architectural expectations upon its receipt.

The test provides command-line options to configure the period of the timer, number of iterations, and number of vCPUs.

Signed-off-by Raghavendra Rao Ananta <[email protected]>

---
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/arch_timer.c        | 382 ++++++++++++++++++
 3 files changed, 384 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/arch_timer.c

tools/testing/selftests/kvm/.gitignore +1 -0

index 0709af0144c8..5f6cf0c76cf8 100644
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+/aarch64/arch_timer
 /aarch64/debug-exceptions
 /aarch64/get-reg-list
 /aarch64/vgic_init

tools/testing/selftests/kvm/Makefile +1 -0

index a170166334a3..62a2c3e4b50c 100644
@@ -84,6 +84,7 @@ TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
 TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
 
+TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +247 -0

new file mode 100644
index 000000000000..88333fe1e567
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch_timer.c - Tests the aarch64 timer IRQ functionality
+ *
+ * The test validates both the virtual and physical timer IRQs using
+ * CVAL and TVAL registers. This consitutes the four stages in the test.
+ * The guest's main thread configures the timer interrupt for a stage
+ * and waits for it to fire, with a timeout equal to the timer period.
+ * It asserts that the timeout doesn't exceed the timer period.
+ *
+ * On the other hand, upon receipt of an interrupt, the guest's interrupt
+ * handler validates the interrupt by checking if the architectural state
+ * is in compliance with the specifications.
+ *
+ * The test provides command-line options to configure the timer's
+ * period (-p), number of vCPUs (-n), and iterations per stage (-i).
+ *
+ * Copyright (c) 2021, Google LLC.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <pthread.h>
+#include <linux/kvm.h>
+#include <linux/sizes.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "delay.h"
+#include "arch_timer.h"
+#include "gic.h"
+
+#define NR_VCPUS_DEF			4
+#define NR_TEST_ITERS_DEF		5
+#define TIMER_TEST_PERIOD_MS_DEF	10
+#define TIMER_TEST_ERR_MARGIN_US	100
+
+struct test_args {
+	int nr_vcpus;
+	int nr_iter;
+	int timer_period_ms;
+};
+
+static struct test_args test_args = {
+	.nr_vcpus = NR_VCPUS_DEF,
+	.nr_iter = NR_TEST_ITERS_DEF,
+	.timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
+};
+
+#define msecs_to_usecs(msec)		((msec) * 1000LL)
+
+#define VTIMER_IRQ			27
+#define PTIMER_IRQ			30
+
+#define REDIST_REGION_ATTR_ADDR(count, base, flags, index) \
+	(((uint64_t)(count) << 52) | \
+	((uint64_t)((base) >> 16) << 16) | \
+	((uint64_t)(flags) << 12) | \
+	index)
+
+#define GICD_BASE_GPA			0x8000000ULL
+#define GICR_BASE_GPA			0x80A0000ULL
+
+enum guest_stage {
+	GUEST_STAGE_VTIMER_CVAL = 1,
+	GUEST_STAGE_VTIMER_TVAL,
+	GUEST_STAGE_PTIMER_CVAL,
+	GUEST_STAGE_PTIMER_TVAL,
+	GUEST_STAGE_MAX,
+};
+
+/* Sahred variables between host and guest */
+struct test_vcpu_shared_data {
+	int nr_iter;
+	enum guest_stage guest_stage;
+	uint64_t xcnt;
+};
+
+struct test_vcpu {
+	uint32_t vcpuid;
+	pthread_t pt_vcpu_run;
+	struct kvm_vm *vm;
+};
+
+static struct test_vcpu test_vcpu[KVM_MAX_VCPUS];
+static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
+
+static void
+guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
+{
+	switch (shared_data->guest_stage) {
+	case GUEST_STAGE_VTIMER_CVAL:
+		timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
+		shared_data->xcnt = timer_get_cntct(VIRTUAL);
+		timer_set_ctl(VIRTUAL, CTL_ENABLE);
+		break;
+	case GUEST_STAGE_VTIMER_TVAL:
+		timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
+		shared_data->xcnt = timer_get_cntct(VIRTUAL);
+		timer_set_ctl(VIRTUAL, CTL_ENABLE);
+		break;
+	case GUEST_STAGE_PTIMER_CVAL:
+		timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
+		shared_data->xcnt = timer_get_cntct(PHYSICAL);
+		timer_set_ctl(PHYSICAL, CTL_ENABLE);
+		break;
+	case GUEST_STAGE_PTIMER_TVAL:
+		timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
+		shared_data->xcnt = timer_get_cntct(PHYSICAL);
+		timer_set_ctl(PHYSICAL, CTL_ENABLE);
+		break;
+	default:
+		GUEST_ASSERT(0);
+	}
+}
+
+static void guest_validate_irq(unsigned int intid,
+				struct test_vcpu_shared_data *shared_data)
+{
+	enum guest_stage stage = shared_data->guest_stage;
+	uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
+	unsigned long xctl = 0;
+	unsigned int timer_irq = 0;
+
+	if (stage == GUEST_STAGE_VTIMER_CVAL ||
+		stage == GUEST_STAGE_VTIMER_TVAL) {
+		xctl = timer_get_ctl(VIRTUAL);
+		timer_set_ctl(VIRTUAL, CTL_IMASK);
+		xcnt = timer_get_cntct(VIRTUAL);
+		cval = timer_get_cval(VIRTUAL);
+		timer_irq = VTIMER_IRQ;
+	} else if (stage == GUEST_STAGE_PTIMER_CVAL ||
+		stage == GUEST_STAGE_PTIMER_TVAL) {
+		xctl = timer_get_ctl(PHYSICAL);
+		timer_set_ctl(PHYSICAL, CTL_IMASK);
+		xcnt = timer_get_cntct(PHYSICAL);
+		cval = timer_get_cval(PHYSICAL);
+		timer_irq = PTIMER_IRQ;
+	} else {
+		GUEST_ASSERT(0);
+	}
+
+	xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
+
+	/* Make sure we are dealing with the correct timer IRQ */
+	GUEST_ASSERT_2(intid == timer_irq, intid, timer_irq);
+
+	/* Basic 'timer codition met' check */
+	GUEST_ASSERT_3(xcnt >= cval, xcnt, cval, xcnt_diff_us);
+	GUEST_ASSERT_1(xctl & CTL_ISTATUS, xctl);
+}
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+	unsigned int intid = gic_get_and_ack_irq();
+	uint32_t cpu = get_vcpuid();
+	struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+	guest_validate_irq(intid, shared_data);
+
+	WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
+
+	gic_set_eoi(intid);
+}
+
+static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
+				enum guest_stage stage)
+{
+	uint32_t irq_iter, config_iter;
+
+	shared_data->guest_stage = stage;
+	shared_data->nr_iter = 0;
+
+	for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
+		/* Setup the next interrupt */
+		guest_configure_timer_action(shared_data);
+
+		/* Setup a timeout for the interrupt to arrive */
+		udelay(msecs_to_usecs(test_args.timer_period_ms) +
+			TIMER_TEST_ERR_MARGIN_US);
+
+		irq_iter = READ_ONCE(shared_data->nr_iter);
+		GUEST_ASSERT_2(config_iter + 1 == irq_iter,
+				config_iter + 1, irq_iter);
+	};
+}
+
+static void guest_code(void)
+{
+	uint32_t cpu = get_vcpuid();
+	struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+	local_irq_disable();
+
+	gic_init(GIC_V3, test_args.nr_vcpus,
+		(void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
+
+	timer_set_ctl(VIRTUAL, CTL_IMASK);
+	timer_set_ctl(PHYSICAL, CTL_IMASK);
+
+	gic_irq_enable(VTIMER_IRQ);
+	gic_irq_enable(PTIMER_IRQ);
+	local_irq_enable();
+
+	guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
+	guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
+	guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
+	guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
+
+	GUEST_DONE();
+}
+
+static void *test_vcpu_run(void *arg)
+{
+	struct ucall uc;
+	struct test_vcpu *vcpu = arg;
+	struct kvm_vm *vm = vcpu->vm;
+	uint32_t vcpuid = vcpu->vcpuid;
+	struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpuid];
+
+	vcpu_run(vm, vcpuid);
+
+	switch (get_ucall(vm, vcpuid, &uc)) {
+	case UCALL_SYNC:
+	case UCALL_DONE:
+		break;
+	case UCALL_ABORT:
+		sync_global_from_guest(vm, *shared_data);
+		TEST_ASSERT(false,
+			"%s at %s:%ld\n\tvalues: %lu, %lu; %lu, vcpu: %u; stage: %u; iter: %u",
+			(const char *)uc.args[0], __FILE__, uc.args[1],
+			uc.args[2], uc.args[3], uc.args[4], vcpuid,
+			shared_data->guest_stage, shared_data->nr_iter);
+		break;
+	default:
+		TEST_FAIL("Unexpected guest exit\n");
+	}
+
+	return NULL;
+}
+
+static void test_run(struct kvm_vm *vm)
+{
+	int i, ret;
+
+	for (i = 0; i < test_args.nr_vcpus; i++) {

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +9 -0

+
+	addr = REDIST_REGION_ATTR_ADDR(test_args.nr_vcpus, GICR_BASE_GPA, 0, 0);
+	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
+			KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
+	virt_map(vm, GICR_BASE_GPA, GICR_BASE_GPA, n_gicr_pages);
+
+	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
+				KVM_DEV_ARM_VGIC_CTRL_INIT, NULL, true);
+}

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +96 -0

+
+	vm = vm_create_default_with_vcpus(nr_vcpus, n_gicr_pages, 0,
+						guest_code, NULL);
+
+	vm_init_descriptor_tables(vm);
+	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
+
+	for (i = 0; i < nr_vcpus; i++) {
+		vcpu_init_descriptor_tables(vm, i);
+
+		test_vcpu[i].vcpuid = i;
+		test_vcpu[i].vm = vm;
+	}
+
+	ucall_init(vm, NULL);
+	test_vm_setup_gic(vm, n_gicr_pages);
+
+	/* Make all the test's cmdline args visible to the guest */
+	sync_global_to_guest(vm, test_args);
+
+	return vm;
+}
+
+static void test_print_help(char *name)
+{
+	pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
+		name);
+	pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
+		NR_VCPUS_DEF, KVM_MAX_VCPUS);
+	pr_info("\t-i: Number of iterations per stage (default: %u)\n",
+		NR_TEST_ITERS_DEF);
+	pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
+		TIMER_TEST_PERIOD_MS_DEF);
+	pr_info("\t-h: print this help screen\n");
+}
+
+static bool parse_args(int argc, char *argv[])
+{
+	int opt;
+
+	while ((opt = getopt(argc, argv, "hn:i:p:")) != -1) {
+		switch (opt) {
+		case 'n':
+			test_args.nr_vcpus = atoi(optarg);
+			if (test_args.nr_vcpus <= 0) {
+				pr_info("Positive value needed for -n\n");
+				goto err;
+			} else if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
+				pr_info("Max allowed vCPUs: %u\n",
+					KVM_MAX_VCPUS);
+				goto err;
+			}
+			break;
+		case 'i':
+			test_args.nr_iter = atoi(optarg);
+			if (test_args.nr_iter <= 0) {
+				pr_info("Positive value needed for -i\n");
+				goto err;
+			}
+			break;
+		case 'p':
+			test_args.timer_period_ms = atoi(optarg);
+			if (test_args.timer_period_ms <= 0) {
+				pr_info("Positive value needed for -p\n");
+				goto err;
+			}
+			break;
+		case 'h':
+		default:
+			goto err;
+		}
+	}
+
+	return true;
+
+err:
+	test_print_help(argv[0]);
+	return false;
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+
+	/* Tell stdout not to buffer its content */
+	setbuf(stdout, NULL);
+
+	if (!parse_args(argc, argv))
+		exit(KSFT_SKIP);
+
+	vm = test_vm_create();
+	test_run(vm);
+	kvm_vm_free(vm);
+
+	return 0;
+}

Signature · 1 line

2.33.0.rc1.237.g0d66db33f3-goog

Quoted 290 lines · Raghavendra Rao Ananta

Add a KVM selftest to validate the arch_timer functionality. Primarily, the test sets up periodic timer interrupts and validates the basic architectural expectations upon its receipt.

The test provides command-line options to configure the period of the timer, number of iterations, and number of vCPUs.

Signed-off-by Raghavendra Rao Ananta <[email protected]>

---
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/arch_timer.c        | 382 ++++++++++++++++++
 3 files changed, 384 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/arch_timer.c

tools/testing/selftests/kvm/.gitignore +1 -0

index 0709af0144c8..5f6cf0c76cf8 100644
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+/aarch64/arch_timer
 /aarch64/debug-exceptions
 /aarch64/get-reg-list
 /aarch64/vgic_init

tools/testing/selftests/kvm/Makefile +1 -0

index a170166334a3..62a2c3e4b50c 100644
@@ -84,6 +84,7 @@ TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
 TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
 
+TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +247 -0

new file mode 100644
index 000000000000..88333fe1e567
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch_timer.c - Tests the aarch64 timer IRQ functionality
+ *
+ * The test validates both the virtual and physical timer IRQs using
+ * CVAL and TVAL registers. This consitutes the four stages in the test.
+ * The guest's main thread configures the timer interrupt for a stage
+ * and waits for it to fire, with a timeout equal to the timer period.
+ * It asserts that the timeout doesn't exceed the timer period.
+ *
+ * On the other hand, upon receipt of an interrupt, the guest's interrupt
+ * handler validates the interrupt by checking if the architectural state
+ * is in compliance with the specifications.
+ *
+ * The test provides command-line options to configure the timer's
+ * period (-p), number of vCPUs (-n), and iterations per stage (-i).
+ *
+ * Copyright (c) 2021, Google LLC.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <pthread.h>
+#include <linux/kvm.h>
+#include <linux/sizes.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "delay.h"
+#include "arch_timer.h"
+#include "gic.h"
+
+#define NR_VCPUS_DEF                 4
+#define NR_TEST_ITERS_DEF            5
+#define TIMER_TEST_PERIOD_MS_DEF     10
+#define TIMER_TEST_ERR_MARGIN_US     100
+
+struct test_args {
+     int nr_vcpus;
+     int nr_iter;
+     int timer_period_ms;
+};
+
+static struct test_args test_args = {
+     .nr_vcpus = NR_VCPUS_DEF,
+     .nr_iter = NR_TEST_ITERS_DEF,
+     .timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
+};
+
+#define msecs_to_usecs(msec)         ((msec) * 1000LL)
+
+#define VTIMER_IRQ                   27
+#define PTIMER_IRQ                   30
+
+#define REDIST_REGION_ATTR_ADDR(count, base, flags, index) \
+     (((uint64_t)(count) << 52) | \
+     ((uint64_t)((base) >> 16) << 16) | \
+     ((uint64_t)(flags) << 12) | \
+     index)
+
+#define GICD_BASE_GPA                        0x8000000ULL
+#define GICR_BASE_GPA                        0x80A0000ULL
+
+enum guest_stage {
+     GUEST_STAGE_VTIMER_CVAL = 1,
+     GUEST_STAGE_VTIMER_TVAL,
+     GUEST_STAGE_PTIMER_CVAL,
+     GUEST_STAGE_PTIMER_TVAL,
+     GUEST_STAGE_MAX,
+};
+
+/* Sahred variables between host and guest */
+struct test_vcpu_shared_data {
+     int nr_iter;
+     enum guest_stage guest_stage;
+     uint64_t xcnt;
+};
+
+struct test_vcpu {
+     uint32_t vcpuid;
+     pthread_t pt_vcpu_run;
+     struct kvm_vm *vm;
+};
+
+static struct test_vcpu test_vcpu[KVM_MAX_VCPUS];
+static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
+
+static void
+guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
+{
+     switch (shared_data->guest_stage) {
+     case GUEST_STAGE_VTIMER_CVAL:
+             timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
+             shared_data->xcnt = timer_get_cntct(VIRTUAL);
+             timer_set_ctl(VIRTUAL, CTL_ENABLE);
+             break;
+     case GUEST_STAGE_VTIMER_TVAL:
+             timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
+             shared_data->xcnt = timer_get_cntct(VIRTUAL);
+             timer_set_ctl(VIRTUAL, CTL_ENABLE);
+             break;
+     case GUEST_STAGE_PTIMER_CVAL:
+             timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
+             shared_data->xcnt = timer_get_cntct(PHYSICAL);
+             timer_set_ctl(PHYSICAL, CTL_ENABLE);
+             break;
+     case GUEST_STAGE_PTIMER_TVAL:
+             timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
+             shared_data->xcnt = timer_get_cntct(PHYSICAL);
+             timer_set_ctl(PHYSICAL, CTL_ENABLE);
+             break;
+     default:
+             GUEST_ASSERT(0);
+     }
+}
+
+static void guest_validate_irq(unsigned int intid,
+                             struct test_vcpu_shared_data *shared_data)
+{
+     enum guest_stage stage = shared_data->guest_stage;
+     uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
+     unsigned long xctl = 0;
+     unsigned int timer_irq = 0;
+
+     if (stage == GUEST_STAGE_VTIMER_CVAL ||
+             stage == GUEST_STAGE_VTIMER_TVAL) {
+             xctl = timer_get_ctl(VIRTUAL);
+             timer_set_ctl(VIRTUAL, CTL_IMASK);
+             xcnt = timer_get_cntct(VIRTUAL);
+             cval = timer_get_cval(VIRTUAL);
+             timer_irq = VTIMER_IRQ;
+     } else if (stage == GUEST_STAGE_PTIMER_CVAL ||
+             stage == GUEST_STAGE_PTIMER_TVAL) {
+             xctl = timer_get_ctl(PHYSICAL);
+             timer_set_ctl(PHYSICAL, CTL_IMASK);
+             xcnt = timer_get_cntct(PHYSICAL);
+             cval = timer_get_cval(PHYSICAL);
+             timer_irq = PTIMER_IRQ;
+     } else {
+             GUEST_ASSERT(0);
+     }
+
+     xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
+
+     /* Make sure we are dealing with the correct timer IRQ */
+     GUEST_ASSERT_2(intid == timer_irq, intid, timer_irq);
+
+     /* Basic 'timer codition met' check */
+     GUEST_ASSERT_3(xcnt >= cval, xcnt, cval, xcnt_diff_us);
+     GUEST_ASSERT_1(xctl & CTL_ISTATUS, xctl);
+}
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+     unsigned int intid = gic_get_and_ack_irq();
+     uint32_t cpu = get_vcpuid();
+     struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+     guest_validate_irq(intid, shared_data);
+
+     WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
+
+     gic_set_eoi(intid);
+}
+
+static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
+                             enum guest_stage stage)
+{
+     uint32_t irq_iter, config_iter;
+
+     shared_data->guest_stage = stage;
+     shared_data->nr_iter = 0;
+
+     for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
+             /* Setup the next interrupt */
+             guest_configure_timer_action(shared_data);
+
+             /* Setup a timeout for the interrupt to arrive */
+             udelay(msecs_to_usecs(test_args.timer_period_ms) +
+                     TIMER_TEST_ERR_MARGIN_US);
+
+             irq_iter = READ_ONCE(shared_data->nr_iter);
+             GUEST_ASSERT_2(config_iter + 1 == irq_iter,
+                             config_iter + 1, irq_iter);
+     };
+}
+
+static void guest_code(void)
+{
+     uint32_t cpu = get_vcpuid();
+     struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+     local_irq_disable();
+
+     gic_init(GIC_V3, test_args.nr_vcpus,
+             (void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
+
+     timer_set_ctl(VIRTUAL, CTL_IMASK);
+     timer_set_ctl(PHYSICAL, CTL_IMASK);
+
+     gic_irq_enable(VTIMER_IRQ);
+     gic_irq_enable(PTIMER_IRQ);
+     local_irq_enable();
+
+     guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
+     guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
+     guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
+     guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
+
+     GUEST_DONE();
+}
+
+static void *test_vcpu_run(void *arg)
+{
+     struct ucall uc;
+     struct test_vcpu *vcpu = arg;
+     struct kvm_vm *vm = vcpu->vm;
+     uint32_t vcpuid = vcpu->vcpuid;
+     struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpuid];
+
+     vcpu_run(vm, vcpuid);
+
+     switch (get_ucall(vm, vcpuid, &uc)) {
+     case UCALL_SYNC:
+     case UCALL_DONE:
+             break;
+     case UCALL_ABORT:
+             sync_global_from_guest(vm, *shared_data);
+             TEST_ASSERT(false,
+                     "%s at %s:%ld\n\tvalues: %lu, %lu; %lu, vcpu: %u; stage: %u; iter: %u",
+                     (const char *)uc.args[0], __FILE__, uc.args[1],
+                     uc.args[2], uc.args[3], uc.args[4], vcpuid,
+                     shared_data->guest_stage, shared_data->nr_iter);
+             break;
+     default:
+             TEST_FAIL("Unexpected guest exit\n");
+     }
+
+     return NULL;
+}
+
+static void test_run(struct kvm_vm *vm)
+{
+     int i, ret;
+
+     for (i = 0; i < test_args.nr_vcpus; i++) {

tools/testing/selftests/kvm/aarch64/arch_timer.c line 257

Quoted 10 lines

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +10 -0

+             ret = pthread_create(&test_vcpu[i].pt_vcpu_run, NULL,
+                             test_vcpu_run, &test_vcpu[i]);
+             TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread\n", i);
+     }
+
+     for (i = 0; i < test_args.nr_vcpus; i++)
+             pthread_join(test_vcpu[i].pt_vcpu_run, NULL);
+}
+
+static void test_vm_setup_gic(struct kvm_vm *vm, unsigned int n_gicr_pages)

I think it's nicer if this takes nr_vcpus instead of gicr_pages.

And, it possible, it would be doubly nice if it could be be made a library function (e.g., inside lib/aarch64/vgic.c?).

Quoted 5 lines

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +5 -0

+{
+     uint64_t addr;
+     int gic_fd;
+
+     gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);

tools/testing/selftests/kvm/aarch64/arch_timer.c line 267

Quoted 5 lines

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +5 -0

+
+     addr = GICD_BASE_GPA;
+     kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
+                             KVM_VGIC_V3_ADDR_TYPE_DIST, &addr, true);
+     virt_pg_map(vm, GICD_BASE_GPA, GICD_BASE_GPA);

Not really a big deal at the moment, but if KVM implemented ESPIs, then a 4k page wouldn't be enough. Why not map 64Ks as there's space for it?

Quoted 18 lines

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +18 -0

+
+     addr = REDIST_REGION_ATTR_ADDR(test_args.nr_vcpus, GICR_BASE_GPA, 0, 0);
+     kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
+                     KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
+     virt_map(vm, GICR_BASE_GPA, GICR_BASE_GPA, n_gicr_pages);
+
+     kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
+                             KVM_DEV_ARM_VGIC_CTRL_INIT, NULL, true);
+}
+
+static struct kvm_vm *test_vm_create(void)
+{
+     struct kvm_vm *vm;
+     unsigned int i, n_gicr_pages;
+     int nr_vcpus = test_args.nr_vcpus;
+
+     /* Reserve additional pages for GICR MMIO based on nr_vcpus */
+     n_gicr_pages = vm_calc_num_guest_pages(VM_MODE_DEFAULT,

tools/testing/selftests/kvm/aarch64/arch_timer.c line 286

Quoted 1 line

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +1 -0

+                                             2 * SZ_64K * nr_vcpus);

Might be better to use vm_get_page_size instead as it doesn't need the mode arg. Note that you would have to call it after creating the vm (vm_create..), but the nice thing is that that call uses the actual mode that the vm was created with. I propose moving this pages calculation to inside test_vm_setup_gic, which could take the number of vcpus as an arg (instead of nr_pages).

Quoted 97 lines

tools/testing/selftests/kvm/aarch64/arch_timer.c new file +96 -1

+
+     vm = vm_create_default_with_vcpus(nr_vcpus, n_gicr_pages, 0,
+                                             guest_code, NULL);
+
+     vm_init_descriptor_tables(vm);
+     vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
+
+     for (i = 0; i < nr_vcpus; i++) {
+             vcpu_init_descriptor_tables(vm, i);
+
+             test_vcpu[i].vcpuid = i;
+             test_vcpu[i].vm = vm;
+     }
+
+     ucall_init(vm, NULL);
+     test_vm_setup_gic(vm, n_gicr_pages);
+
+     /* Make all the test's cmdline args visible to the guest */
+     sync_global_to_guest(vm, test_args);
+
+     return vm;
+}
+
+static void test_print_help(char *name)
+{
+     pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
+             name);
+     pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
+             NR_VCPUS_DEF, KVM_MAX_VCPUS);
+     pr_info("\t-i: Number of iterations per stage (default: %u)\n",
+             NR_TEST_ITERS_DEF);
+     pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
+             TIMER_TEST_PERIOD_MS_DEF);
+     pr_info("\t-h: print this help screen\n");
+}
+
+static bool parse_args(int argc, char *argv[])
+{
+     int opt;
+
+     while ((opt = getopt(argc, argv, "hn:i:p:")) != -1) {
+             switch (opt) {
+             case 'n':
+                     test_args.nr_vcpus = atoi(optarg);
+                     if (test_args.nr_vcpus <= 0) {
+                             pr_info("Positive value needed for -n\n");
+                             goto err;
+                     } else if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
+                             pr_info("Max allowed vCPUs: %u\n",
+                                     KVM_MAX_VCPUS);
+                             goto err;
+                     }
+                     break;
+             case 'i':
+                     test_args.nr_iter = atoi(optarg);
+                     if (test_args.nr_iter <= 0) {
+                             pr_info("Positive value needed for -i\n");
+                             goto err;
+                     }
+                     break;
+             case 'p':
+                     test_args.timer_period_ms = atoi(optarg);
+                     if (test_args.timer_period_ms <= 0) {
+                             pr_info("Positive value needed for -p\n");
+                             goto err;
+                     }
+                     break;
+             case 'h':
+             default:
+                     goto err;
+             }
+     }
+
+     return true;
+
+err:
+     test_print_help(argv[0]);
+     return false;
+}
+
+int main(int argc, char *argv[])
+{
+     struct kvm_vm *vm;
+
+     /* Tell stdout not to buffer its content */
+     setbuf(stdout, NULL);
+
+     if (!parse_args(argc, argv))
+             exit(KSFT_SKIP);
+
+     vm = test_vm_create();
+     test_run(vm);
+     kvm_vm_free(vm);
+
+     return 0;
+}
--

Quoted 2 lines

2.33.0.rc1.237.g0d66db33f3-goog

Thanks,
Ricardo