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
25 static size_t nr_iterations = 1000;
26 static vm_paddr_t gpa_base;
27
28 static struct kvm_vm *vm;
29 static struct kvm_vcpu **vcpus;
30 static int gic_fd, its_fd;
31
32 static 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
52 static 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
63 static 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
90 static 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
98 static 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
123 static 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
139 static 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
168 static 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
181 static 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
215 static 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
223 static 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
243 static pthread_barrier_t test_setup_barrier;
244
245 static 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
260 static 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
285 static 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
298 static 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
333 static 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
355 static void destroy_vm(void)
356 {
357 close(its_fd);
358 close(gic_fd);
359 kvm_vm_free(vm);
360 free(vcpus);
361 }
362
363 static 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
372 int 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
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