1// SPDX-License-Identifier: GPL-2.0
2/*
3 * vgic_lpi_stress - Stress test for KVM's ITS emulation
4 *
5 * Copyright (c) 2024 Google LLC
6 */
7
8#include <linux/sizes.h>
9#include <pthread.h>
10#include <stdatomic.h>
11#include <sys/sysinfo.h>
12
13#include "kvm_util.h"
14#include "gic.h"
15#include "gic_v3.h"
16#include "gic_v3_its.h"
17#include "processor.h"
18#include "ucall.h"
19#include "vgic.h"
20
21#define TEST_MEMSLOT_INDEX	1
22
23#define GIC_LPI_OFFSET	8192
24
25static size_t nr_iterations = 1000;
26static vm_paddr_t gpa_base;
27
28static struct kvm_vm *vm;
29static struct kvm_vcpu **vcpus;
30static int gic_fd, its_fd;
31
32static struct test_data {
33	bool		request_vcpus_stop;
34	u32		nr_cpus;
35	u32		nr_devices;
36	u32		nr_event_ids;
37
38	vm_paddr_t	device_table;
39	vm_paddr_t	collection_table;
40	vm_paddr_t	cmdq_base;
41	void		*cmdq_base_va;
42	vm_paddr_t	itt_tables;
43
44	vm_paddr_t	lpi_prop_table;
45	vm_paddr_t	lpi_pend_tables;
46} test_data =  {
47	.nr_cpus	= 1,
48	.nr_devices	= 1,
49	.nr_event_ids	= 16,
50};
51
52static void guest_irq_handler(struct ex_regs *regs)
53{
54	u32 intid = gic_get_and_ack_irq();
55
56	if (intid == IAR_SPURIOUS)
57		return;
58
59	GUEST_ASSERT(intid >= GIC_LPI_OFFSET);
60	gic_set_eoi(intid);
61}
62
63static void guest_setup_its_mappings(void)
64{
65	u32 coll_id, device_id, event_id, intid = GIC_LPI_OFFSET;
66	u32 nr_events = test_data.nr_event_ids;
67	u32 nr_devices = test_data.nr_devices;
68	u32 nr_cpus = test_data.nr_cpus;
69
70	for (coll_id = 0; coll_id < nr_cpus; coll_id++)
71		its_send_mapc_cmd(test_data.cmdq_base_va, coll_id, coll_id, true);
72
73	/* Round-robin the LPIs to all of the vCPUs in the VM */
74	coll_id = 0;
75	for (device_id = 0; device_id < nr_devices; device_id++) {
76		vm_paddr_t itt_base = test_data.itt_tables + (device_id * SZ_64K);
77
78		its_send_mapd_cmd(test_data.cmdq_base_va, device_id,
79				  itt_base, SZ_64K, true);
80
81		for (event_id = 0; event_id < nr_events; event_id++) {
82			its_send_mapti_cmd(test_data.cmdq_base_va, device_id,
83					   event_id, coll_id, intid++);
84
85			coll_id = (coll_id + 1) % test_data.nr_cpus;
86		}
87	}
88}
89
90static void guest_invalidate_all_rdists(void)
91{
92	int i;
93
94	for (i = 0; i < test_data.nr_cpus; i++)
95		its_send_invall_cmd(test_data.cmdq_base_va, i);
96}
97
98static void guest_setup_gic(void)
99{
100	static atomic_int nr_cpus_ready = 0;
101	u32 cpuid = guest_get_vcpuid();
102
103	gic_init(GIC_V3, test_data.nr_cpus);
104	gic_rdist_enable_lpis(test_data.lpi_prop_table, SZ_64K,
105			      test_data.lpi_pend_tables + (cpuid * SZ_64K));
106
107	atomic_fetch_add(&nr_cpus_ready, 1);
108
109	if (cpuid > 0)
110		return;
111
112	while (atomic_load(&nr_cpus_ready) < test_data.nr_cpus)
113		cpu_relax();
114
115	its_init(test_data.collection_table, SZ_64K,
116		 test_data.device_table, SZ_64K,
117		 test_data.cmdq_base, SZ_64K);
118
119	guest_setup_its_mappings();
120	guest_invalidate_all_rdists();
121}
122
123static void guest_code(size_t nr_lpis)
124{
125	guest_setup_gic();
126
127	GUEST_SYNC(0);
128
129	/*
130	 * Don't use WFI here to avoid blocking the vCPU thread indefinitely and
131	 * never getting the stop signal.
132	 */
133	while (!READ_ONCE(test_data.request_vcpus_stop))
134		cpu_relax();
135
136	GUEST_DONE();
137}
138
139static void setup_memslot(void)
140{
141	size_t pages;
142	size_t sz;
143
144	/*
145	 * For the ITS:
146	 *  - A single level device table
147	 *  - A single level collection table
148	 *  - The command queue
149	 *  - An ITT for each device
150	 */
151	sz = (3 + test_data.nr_devices) * SZ_64K;
152
153	/*
154	 * For the redistributors:
155	 *  - A shared LPI configuration table
156	 *  - An LPI pending table for each vCPU
157	 */
158	sz += (1 + test_data.nr_cpus) * SZ_64K;
159
160	pages = sz / vm->page_size;
161	gpa_base = ((vm_compute_max_gfn(vm) + 1) * vm->page_size) - sz;
162	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa_base,
163				    TEST_MEMSLOT_INDEX, pages, 0);
164}
165
166#define LPI_PROP_DEFAULT_PRIO	0xa0
167
168static void configure_lpis(void)
169{
170	size_t nr_lpis = test_data.nr_devices * test_data.nr_event_ids;
171	u8 *tbl = addr_gpa2hva(vm, test_data.lpi_prop_table);
172	size_t i;
173
174	for (i = 0; i < nr_lpis; i++) {
175		tbl[i] = LPI_PROP_DEFAULT_PRIO |
176			 LPI_PROP_GROUP1 |
177			 LPI_PROP_ENABLED;
178	}
179}
180
181static void setup_test_data(void)
182{
183	size_t pages_per_64k = vm_calc_num_guest_pages(vm->mode, SZ_64K);
184	u32 nr_devices = test_data.nr_devices;
185	u32 nr_cpus = test_data.nr_cpus;
186	vm_paddr_t cmdq_base;
187
188	test_data.device_table = vm_phy_pages_alloc(vm, pages_per_64k,
189						    gpa_base,
190						    TEST_MEMSLOT_INDEX);
191
192	test_data.collection_table = vm_phy_pages_alloc(vm, pages_per_64k,
193							gpa_base,
194							TEST_MEMSLOT_INDEX);
195
196	cmdq_base = vm_phy_pages_alloc(vm, pages_per_64k, gpa_base,
197				       TEST_MEMSLOT_INDEX);
198	virt_map(vm, cmdq_base, cmdq_base, pages_per_64k);
199	test_data.cmdq_base = cmdq_base;
200	test_data.cmdq_base_va = (void *)cmdq_base;
201
202	test_data.itt_tables = vm_phy_pages_alloc(vm, pages_per_64k * nr_devices,
203						  gpa_base, TEST_MEMSLOT_INDEX);
204
205	test_data.lpi_prop_table = vm_phy_pages_alloc(vm, pages_per_64k,
206						      gpa_base, TEST_MEMSLOT_INDEX);
207	configure_lpis();
208
209	test_data.lpi_pend_tables = vm_phy_pages_alloc(vm, pages_per_64k * nr_cpus,
210						       gpa_base, TEST_MEMSLOT_INDEX);
211
212	sync_global_to_guest(vm, test_data);
213}
214
215static void setup_gic(void)
216{
217	gic_fd = vgic_v3_setup(vm, test_data.nr_cpus, 64);
218	__TEST_REQUIRE(gic_fd >= 0, "Failed to create GICv3");
219
220	its_fd = vgic_its_setup(vm);
221}
222
223static void signal_lpi(u32 device_id, u32 event_id)
224{
225	vm_paddr_t db_addr = GITS_BASE_GPA + GITS_TRANSLATER;
226
227	struct kvm_msi msi = {
228		.address_lo	= db_addr,
229		.address_hi	= db_addr >> 32,
230		.data		= event_id,
231		.devid		= device_id,
232		.flags		= KVM_MSI_VALID_DEVID,
233	};
234
235	/*
236	 * KVM_SIGNAL_MSI returns 1 if the MSI wasn't 'blocked' by the VM,
237	 * which for arm64 implies having a valid translation in the ITS.
238	 */
239	TEST_ASSERT(__vm_ioctl(vm, KVM_SIGNAL_MSI, &msi) == 1,
240		    "KVM_SIGNAL_MSI ioctl failed");
241}
242
243static pthread_barrier_t test_setup_barrier;
244
245static void *lpi_worker_thread(void *data)
246{
247	u32 device_id = (size_t)data;
248	u32 event_id;
249	size_t i;
250
251	pthread_barrier_wait(&test_setup_barrier);
252
253	for (i = 0; i < nr_iterations; i++)
254		for (event_id = 0; event_id < test_data.nr_event_ids; event_id++)
255			signal_lpi(device_id, event_id);
256
257	return NULL;
258}
259
260static void *vcpu_worker_thread(void *data)
261{
262	struct kvm_vcpu *vcpu = data;
263	struct ucall uc;
264
265	while (true) {
266		vcpu_run(vcpu);
267
268		switch (get_ucall(vcpu, &uc)) {
269		case UCALL_SYNC:
270			pthread_barrier_wait(&test_setup_barrier);
271			continue;
272		case UCALL_DONE:
273			return NULL;
274		case UCALL_ABORT:
275			REPORT_GUEST_ASSERT(uc);
276			break;
277		default:
278			TEST_FAIL("Unknown ucall: %lu", uc.cmd);
279		}
280	}
281
282	return NULL;
283}
284
285static void report_stats(struct timespec delta)
286{
287	double nr_lpis;
288	double time;
289
290	nr_lpis = test_data.nr_devices * test_data.nr_event_ids * nr_iterations;
291
292	time = delta.tv_sec;
293	time += ((double)delta.tv_nsec) / NSEC_PER_SEC;
294
295	pr_info("Rate: %.2f LPIs/sec\n", nr_lpis / time);
296}
297
298static void run_test(void)
299{
300	u32 nr_devices = test_data.nr_devices;
301	u32 nr_vcpus = test_data.nr_cpus;
302	pthread_t *lpi_threads = malloc(nr_devices * sizeof(pthread_t));
303	pthread_t *vcpu_threads = malloc(nr_vcpus * sizeof(pthread_t));
304	struct timespec start, delta;
305	size_t i;
306
307	TEST_ASSERT(lpi_threads && vcpu_threads, "Failed to allocate pthread arrays");
308
309	pthread_barrier_init(&test_setup_barrier, NULL, nr_vcpus + nr_devices + 1);
310
311	for (i = 0; i < nr_vcpus; i++)
312		pthread_create(&vcpu_threads[i], NULL, vcpu_worker_thread, vcpus[i]);
313
314	for (i = 0; i < nr_devices; i++)
315		pthread_create(&lpi_threads[i], NULL, lpi_worker_thread, (void *)i);
316
317	pthread_barrier_wait(&test_setup_barrier);
318
319	clock_gettime(CLOCK_MONOTONIC, &start);
320
321	for (i = 0; i < nr_devices; i++)
322		pthread_join(lpi_threads[i], NULL);
323
324	delta = timespec_elapsed(start);
325	write_guest_global(vm, test_data.request_vcpus_stop, true);
326
327	for (i = 0; i < nr_vcpus; i++)
328		pthread_join(vcpu_threads[i], NULL);
329
330	report_stats(delta);
331}
332
333static void setup_vm(void)
334{
335	int i;
336
337	vcpus = malloc(test_data.nr_cpus * sizeof(struct kvm_vcpu));
338	TEST_ASSERT(vcpus, "Failed to allocate vCPU array");
339
340	vm = vm_create_with_vcpus(test_data.nr_cpus, guest_code, vcpus);
341
342	vm_init_descriptor_tables(vm);
343	for (i = 0; i < test_data.nr_cpus; i++)
344		vcpu_init_descriptor_tables(vcpus[i]);
345
346	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
347
348	setup_memslot();
349
350	setup_gic();
351
352	setup_test_data();
353}
354
355static void destroy_vm(void)
356{
357	close(its_fd);
358	close(gic_fd);
359	kvm_vm_free(vm);
360	free(vcpus);
361}
362
363static void pr_usage(const char *name)
364{
365	pr_info("%s [-v NR_VCPUS] [-d NR_DEVICES] [-e NR_EVENTS] [-i ITERS] -h\n", name);
366	pr_info("  -v:\tnumber of vCPUs (default: %u)\n", test_data.nr_cpus);
367	pr_info("  -d:\tnumber of devices (default: %u)\n", test_data.nr_devices);
368	pr_info("  -e:\tnumber of event IDs per device (default: %u)\n", test_data.nr_event_ids);
369	pr_info("  -i:\tnumber of iterations (default: %lu)\n", nr_iterations);
370}
371
372int main(int argc, char **argv)
373{
374	u32 nr_threads;
375	int c;
376
377	while ((c = getopt(argc, argv, "hv:d:e:i:")) != -1) {
378		switch (c) {
379		case 'v':
380			test_data.nr_cpus = atoi(optarg);
381			break;
382		case 'd':
383			test_data.nr_devices = atoi(optarg);
384			break;
385		case 'e':
386			test_data.nr_event_ids = atoi(optarg);
387			break;
388		case 'i':
389			nr_iterations = strtoul(optarg, NULL, 0);
390			break;
391		case 'h':
392		default:
393			pr_usage(argv[0]);
394			return 1;
395		}
396	}
397
398	nr_threads = test_data.nr_cpus + test_data.nr_devices;
399	if (nr_threads > get_nprocs())
400		pr_info("WARNING: running %u threads on %d CPUs; performance is degraded.\n",
401			 nr_threads, get_nprocs());
402
403	setup_vm();
404
405	run_test();
406
407	destroy_vm();
408
409	return 0;
410}
411