1 files changed, 410 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/aarch64/vgic_lpi_stress.c b/tools/testing/selftests/kvm/aarch64/vgic_lpi_stress.c
new file mode 100644
index 000000000000..fc4fe52fb6f8
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/vgic_lpi_stress.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * vgic_lpi_stress - Stress test for KVM's ITS emulation
+ *
+ * Copyright (c) 2024 Google LLC
+ */
+
+#include <linux/sizes.h>
+#include <pthread.h>
+#include <stdatomic.h>
+#include <sys/sysinfo.h>
+
+#include "kvm_util.h"
+#include "gic.h"
+#include "gic_v3.h"
+#include "gic_v3_its.h"
+#include "processor.h"
+#include "ucall.h"
+#include "vgic.h"
+
+#define TEST_MEMSLOT_INDEX	1
+
+#define GIC_LPI_OFFSET	8192
+
+static size_t nr_iterations = 1000;
+static vm_paddr_t gpa_base;
+
+static struct kvm_vm *vm;
+static struct kvm_vcpu **vcpus;
+static int gic_fd, its_fd;
+
+static struct test_data {
+	bool		request_vcpus_stop;
+	u32		nr_cpus;
+	u32		nr_devices;
+	u32		nr_event_ids;
+
+	vm_paddr_t	device_table;
+	vm_paddr_t	collection_table;
+	vm_paddr_t	cmdq_base;
+	void		*cmdq_base_va;
+	vm_paddr_t	itt_tables;
+
+	vm_paddr_t	lpi_prop_table;
+	vm_paddr_t	lpi_pend_tables;
+} test_data =  {
+	.nr_cpus	= 1,
+	.nr_devices	= 1,
+	.nr_event_ids	= 16,
+};
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+	u32 intid = gic_get_and_ack_irq();
+
+	if (intid == IAR_SPURIOUS)
+		return;
+
+	GUEST_ASSERT(intid >= GIC_LPI_OFFSET);
+	gic_set_eoi(intid);
+}
+
+static void guest_setup_its_mappings(void)
+{
+	u32 coll_id, device_id, event_id, intid = GIC_LPI_OFFSET;
+	u32 nr_events = test_data.nr_event_ids;
+	u32 nr_devices = test_data.nr_devices;
+	u32 nr_cpus = test_data.nr_cpus;
+
+	for (coll_id = 0; coll_id < nr_cpus; coll_id++)
+		its_send_mapc_cmd(test_data.cmdq_base_va, coll_id, coll_id, true);
+
+	/* Round-robin the LPIs to all of the vCPUs in the VM */
+	coll_id = 0;
+	for (device_id = 0; device_id < nr_devices; device_id++) {
+		vm_paddr_t itt_base = test_data.itt_tables + (device_id * SZ_64K);
+
+		its_send_mapd_cmd(test_data.cmdq_base_va, device_id,
+				  itt_base, SZ_64K, true);
+
+		for (event_id = 0; event_id < nr_events; event_id++) {
+			its_send_mapti_cmd(test_data.cmdq_base_va, device_id,
+					   event_id, coll_id, intid++);
+
+			coll_id = (coll_id + 1) % test_data.nr_cpus;
+		}
+	}
+}
+
+static void guest_invalidate_all_rdists(void)
+{
+	int i;
+
+	for (i = 0; i < test_data.nr_cpus; i++)
+		its_send_invall_cmd(test_data.cmdq_base_va, i);
+}
+
+static void guest_setup_gic(void)
+{
+	static atomic_int nr_cpus_ready = 0;
+	u32 cpuid = guest_get_vcpuid();
+
+	gic_init(GIC_V3, test_data.nr_cpus);
+	gic_rdist_enable_lpis(test_data.lpi_prop_table, SZ_64K,
+			      test_data.lpi_pend_tables + (cpuid * SZ_64K));
+
+	atomic_fetch_add(&nr_cpus_ready, 1);
+
+	if (cpuid > 0)
+		return;
+
+	while (atomic_load(&nr_cpus_ready) < test_data.nr_cpus)
+		cpu_relax();
+
+	its_init(test_data.collection_table, SZ_64K,
+		 test_data.device_table, SZ_64K,
+		 test_data.cmdq_base, SZ_64K);
+
+	guest_setup_its_mappings();
+	guest_invalidate_all_rdists();
+}
+
+static void guest_code(size_t nr_lpis)
+{
+	guest_setup_gic();
+
+	GUEST_SYNC(0);
+
+	/*
+	 * Don't use WFI here to avoid blocking the vCPU thread indefinitely and
+	 * never getting the stop signal.
+	 */
+	while (!READ_ONCE(test_data.request_vcpus_stop))
+		cpu_relax();
+
+	GUEST_DONE();
+}
+
+static void setup_memslot(void)
+{
+	size_t pages;
+	size_t sz;
+
+	/*
+	 * For the ITS:
+	 *  - A single level device table
+	 *  - A single level collection table
+	 *  - The command queue
+	 *  - An ITT for each device
+	 */
+	sz = (3 + test_data.nr_devices) * SZ_64K;
+
+	/*
+	 * For the redistributors:
+	 *  - A shared LPI configuration table
+	 *  - An LPI pending table for each vCPU
+	 */
+	sz += (1 + test_data.nr_cpus) * SZ_64K;
+
+	pages = sz / vm->page_size;
+	gpa_base = ((vm_compute_max_gfn(vm) + 1) * vm->page_size) - sz;
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa_base,
+				    TEST_MEMSLOT_INDEX, pages, 0);
+}
+
+#define LPI_PROP_DEFAULT_PRIO	0xa0
+
+static void configure_lpis(void)
+{
+	size_t nr_lpis = test_data.nr_devices * test_data.nr_event_ids;
+	u8 *tbl = addr_gpa2hva(vm, test_data.lpi_prop_table);
+	size_t i;
+
+	for (i = 0; i < nr_lpis; i++) {
+		tbl[i] = LPI_PROP_DEFAULT_PRIO |
+			 LPI_PROP_GROUP1 |
+			 LPI_PROP_ENABLED;
+	}
+}
+
+static void setup_test_data(void)
+{
+	size_t pages_per_64k = vm_calc_num_guest_pages(vm->mode, SZ_64K);
+	u32 nr_devices = test_data.nr_devices;
+	u32 nr_cpus = test_data.nr_cpus;
+	vm_paddr_t cmdq_base;
+
+	test_data.device_table = vm_phy_pages_alloc(vm, pages_per_64k,
+						    gpa_base,
+						    TEST_MEMSLOT_INDEX);
+
+	test_data.collection_table = vm_phy_pages_alloc(vm, pages_per_64k,
+							gpa_base,
+							TEST_MEMSLOT_INDEX);
+
+	cmdq_base = vm_phy_pages_alloc(vm, pages_per_64k, gpa_base,
+				       TEST_MEMSLOT_INDEX);
+	virt_map(vm, cmdq_base, cmdq_base, pages_per_64k);
+	test_data.cmdq_base = cmdq_base;
+	test_data.cmdq_base_va = (void *)cmdq_base;
+
+	test_data.itt_tables = vm_phy_pages_alloc(vm, pages_per_64k * nr_devices,
+						  gpa_base, TEST_MEMSLOT_INDEX);
+
+	test_data.lpi_prop_table = vm_phy_pages_alloc(vm, pages_per_64k,
+						      gpa_base, TEST_MEMSLOT_INDEX);
+	configure_lpis();
+
+	test_data.lpi_pend_tables = vm_phy_pages_alloc(vm, pages_per_64k * nr_cpus,
+						       gpa_base, TEST_MEMSLOT_INDEX);
+
+	sync_global_to_guest(vm, test_data);
+}
+
+static void setup_gic(void)
+{
+	gic_fd = vgic_v3_setup(vm, test_data.nr_cpus, 64);
+	__TEST_REQUIRE(gic_fd >= 0, "Failed to create GICv3");
+
+	its_fd = vgic_its_setup(vm);
+}
+
+static void signal_lpi(u32 device_id, u32 event_id)
+{
+	vm_paddr_t db_addr = GITS_BASE_GPA + GITS_TRANSLATER;
+
+	struct kvm_msi msi = {
+		.address_lo	= db_addr,
+		.address_hi	= db_addr >> 32,
+		.data		= event_id,
+		.devid		= device_id,
+		.flags		= KVM_MSI_VALID_DEVID,
+	};
+
+	/*
+	 * KVM_SIGNAL_MSI returns 1 if the MSI wasn't 'blocked' by the VM,
+	 * which for arm64 implies having a valid translation in the ITS.
+	 */
+	TEST_ASSERT(__vm_ioctl(vm, KVM_SIGNAL_MSI, &msi) == 1,
+		    "KVM_SIGNAL_MSI ioctl failed");
+}
+
+static pthread_barrier_t test_setup_barrier;
+
+static void *lpi_worker_thread(void *data)
+{
+	u32 device_id = (size_t)data;
+	u32 event_id;
+	size_t i;
+
+	pthread_barrier_wait(&test_setup_barrier);
+
+	for (i = 0; i < nr_iterations; i++)
+		for (event_id = 0; event_id < test_data.nr_event_ids; event_id++)
+			signal_lpi(device_id, event_id);
+
+	return NULL;
+}
+
+static void *vcpu_worker_thread(void *data)
+{
+	struct kvm_vcpu *vcpu = data;
+	struct ucall uc;
+
+	while (true) {
+		vcpu_run(vcpu);
+
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_SYNC:
+			pthread_barrier_wait(&test_setup_barrier);
+			continue;
+		case UCALL_DONE:
+			return NULL;
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		default:
+			TEST_FAIL("Unknown ucall: %lu", uc.cmd);
+		}
+	}
+
+	return NULL;
+}
+
+static void report_stats(struct timespec delta)
+{
+	double nr_lpis;
+	double time;
+
+	nr_lpis = test_data.nr_devices * test_data.nr_event_ids * nr_iterations;
+
+	time = delta.tv_sec;
+	time += ((double)delta.tv_nsec) / NSEC_PER_SEC;
+
+	pr_info("Rate: %.2f LPIs/sec\n", nr_lpis / time);
+}
+
+static void run_test(void)
+{
+	u32 nr_devices = test_data.nr_devices;
+	u32 nr_vcpus = test_data.nr_cpus;
+	pthread_t *lpi_threads = malloc(nr_devices * sizeof(pthread_t));
+	pthread_t *vcpu_threads = malloc(nr_vcpus * sizeof(pthread_t));
+	struct timespec start, delta;
+	size_t i;
+
+	TEST_ASSERT(lpi_threads && vcpu_threads, "Failed to allocate pthread arrays");
+
+	pthread_barrier_init(&test_setup_barrier, NULL, nr_vcpus + nr_devices + 1);
+
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_create(&vcpu_threads[i], NULL, vcpu_worker_thread, vcpus[i]);
+
+	for (i = 0; i < nr_devices; i++)
+		pthread_create(&lpi_threads[i], NULL, lpi_worker_thread, (void *)i);
+
+	pthread_barrier_wait(&test_setup_barrier);
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+
+	for (i = 0; i < nr_devices; i++)
+		pthread_join(lpi_threads[i], NULL);
+
+	delta = timespec_elapsed(start);
+	write_guest_global(vm, test_data.request_vcpus_stop, true);
+
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_join(vcpu_threads[i], NULL);
+
+	report_stats(delta);
+}
+
+static void setup_vm(void)
+{
+	int i;
+
+	vcpus = malloc(test_data.nr_cpus * sizeof(struct kvm_vcpu));
+	TEST_ASSERT(vcpus, "Failed to allocate vCPU array");
+
+	vm = vm_create_with_vcpus(test_data.nr_cpus, guest_code, vcpus);
+
+	vm_init_descriptor_tables(vm);
+	for (i = 0; i < test_data.nr_cpus; i++)
+		vcpu_init_descriptor_tables(vcpus[i]);
+
+	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
+
+	setup_memslot();
+
+	setup_gic();
+
+	setup_test_data();
+}
+
+static void destroy_vm(void)
+{
+	close(its_fd);
+	close(gic_fd);
+	kvm_vm_free(vm);
+	free(vcpus);
+}
+
+static void pr_usage(const char *name)
+{
+	pr_info("%s [-v NR_VCPUS] [-d NR_DEVICES] [-e NR_EVENTS] [-i ITERS] -h\n", name);
+	pr_info("  -v:\tnumber of vCPUs (default: %u)\n", test_data.nr_cpus);
+	pr_info("  -d:\tnumber of devices (default: %u)\n", test_data.nr_devices);
+	pr_info("  -e:\tnumber of event IDs per device (default: %u)\n", test_data.nr_event_ids);
+	pr_info("  -i:\tnumber of iterations (default: %lu)\n", nr_iterations);
+}
+
+int main(int argc, char **argv)
+{
+	u32 nr_threads;
+	int c;
+
+	while ((c = getopt(argc, argv, "hv:d:e:i:")) != -1) {
+		switch (c) {
+		case 'v':
+			test_data.nr_cpus = atoi(optarg);
+			break;
+		case 'd':
+			test_data.nr_devices = atoi(optarg);
+			break;
+		case 'e':
+			test_data.nr_event_ids = atoi(optarg);
+			break;
+		case 'i':
+			nr_iterations = strtoul(optarg, NULL, 0);
+			break;
+		case 'h':
+		default:
+			pr_usage(argv[0]);
+			return 1;
+		}
+	}
+
+	nr_threads = test_data.nr_cpus + test_data.nr_devices;
+	if (nr_threads > get_nprocs())
+		pr_info("WARNING: running %u threads on %d CPUs; performance is degraded.\n",
+			 nr_threads, get_nprocs());
+
+	setup_vm();
+
+	run_test();
+
+	destroy_vm();
+
+	return 0;
+}