1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * KVM dirty page logging performance test
4 *
5 * Based on dirty_log_test.c
6 *
7 * Copyright (C) 2018, Red Hat, Inc.
8 * Copyright (C) 2020, Google, Inc.
9 */
10
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <time.h>
14 #include <pthread.h>
15 #include <linux/bitmap.h>
16
17 #include "kvm_util.h"
18 #include "test_util.h"
19 #include "perf_test_util.h"
20 #include "guest_modes.h"
21
22 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
23 #define TEST_HOST_LOOP_N 2UL
24
25 static int nr_vcpus = 1;
26 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
27
28 /* Host variables */
29 static u64 dirty_log_manual_caps;
30 static bool host_quit;
31 static int iteration;
32 static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
33
vcpu_worker(void * data)34 static void *vcpu_worker(void *data)
35 {
36 int ret;
37 struct kvm_vm *vm = perf_test_args.vm;
38 uint64_t pages_count = 0;
39 struct kvm_run *run;
40 struct timespec start;
41 struct timespec ts_diff;
42 struct timespec total = (struct timespec){0};
43 struct timespec avg;
44 struct perf_test_vcpu_args *vcpu_args = (struct perf_test_vcpu_args *)data;
45 int vcpu_id = vcpu_args->vcpu_id;
46
47 vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
48 run = vcpu_state(vm, vcpu_id);
49
50 while (!READ_ONCE(host_quit)) {
51 int current_iteration = READ_ONCE(iteration);
52
53 clock_gettime(CLOCK_MONOTONIC, &start);
54 ret = _vcpu_run(vm, vcpu_id);
55 ts_diff = timespec_elapsed(start);
56
57 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
58 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
59 "Invalid guest sync status: exit_reason=%s\n",
60 exit_reason_str(run->exit_reason));
61
62 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
63 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
64 pr_debug("vCPU %d updated last completed iteration to %d\n",
65 vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
66
67 if (current_iteration) {
68 pages_count += vcpu_args->pages;
69 total = timespec_add(total, ts_diff);
70 pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
71 vcpu_id, current_iteration, ts_diff.tv_sec,
72 ts_diff.tv_nsec);
73 } else {
74 pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
75 vcpu_id, current_iteration, ts_diff.tv_sec,
76 ts_diff.tv_nsec);
77 }
78
79 while (current_iteration == READ_ONCE(iteration) &&
80 !READ_ONCE(host_quit)) {}
81 }
82
83 avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
84 pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
85 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
86 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
87
88 return NULL;
89 }
90
91 struct test_params {
92 unsigned long iterations;
93 uint64_t phys_offset;
94 int wr_fract;
95 bool partition_vcpu_memory_access;
96 enum vm_mem_backing_src_type backing_src;
97 };
98
run_test(enum vm_guest_mode mode,void * arg)99 static void run_test(enum vm_guest_mode mode, void *arg)
100 {
101 struct test_params *p = arg;
102 pthread_t *vcpu_threads;
103 struct kvm_vm *vm;
104 unsigned long *bmap;
105 uint64_t guest_num_pages;
106 uint64_t host_num_pages;
107 int vcpu_id;
108 struct timespec start;
109 struct timespec ts_diff;
110 struct timespec get_dirty_log_total = (struct timespec){0};
111 struct timespec vcpu_dirty_total = (struct timespec){0};
112 struct timespec avg;
113 struct kvm_enable_cap cap = {};
114 struct timespec clear_dirty_log_total = (struct timespec){0};
115
116 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
117 p->backing_src);
118
119 perf_test_args.wr_fract = p->wr_fract;
120
121 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
122 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
123 host_num_pages = vm_num_host_pages(mode, guest_num_pages);
124 bmap = bitmap_alloc(host_num_pages);
125
126 if (dirty_log_manual_caps) {
127 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
128 cap.args[0] = dirty_log_manual_caps;
129 vm_enable_cap(vm, &cap);
130 }
131
132 vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
133 TEST_ASSERT(vcpu_threads, "Memory allocation failed");
134
135 perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
136 p->partition_vcpu_memory_access);
137
138 sync_global_to_guest(vm, perf_test_args);
139
140 /* Start the iterations */
141 iteration = 0;
142 host_quit = false;
143
144 clock_gettime(CLOCK_MONOTONIC, &start);
145 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
146 vcpu_last_completed_iteration[vcpu_id] = -1;
147
148 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
149 &perf_test_args.vcpu_args[vcpu_id]);
150 }
151
152 /* Allow the vCPUs to populate memory */
153 pr_debug("Starting iteration %d - Populating\n", iteration);
154 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
155 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
156 iteration)
157 ;
158 }
159
160 ts_diff = timespec_elapsed(start);
161 pr_info("Populate memory time: %ld.%.9lds\n",
162 ts_diff.tv_sec, ts_diff.tv_nsec);
163
164 /* Enable dirty logging */
165 clock_gettime(CLOCK_MONOTONIC, &start);
166 vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX,
167 KVM_MEM_LOG_DIRTY_PAGES);
168 ts_diff = timespec_elapsed(start);
169 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
170 ts_diff.tv_sec, ts_diff.tv_nsec);
171
172 while (iteration < p->iterations) {
173 /*
174 * Incrementing the iteration number will start the vCPUs
175 * dirtying memory again.
176 */
177 clock_gettime(CLOCK_MONOTONIC, &start);
178 iteration++;
179
180 pr_debug("Starting iteration %d\n", iteration);
181 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
182 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
183 != iteration)
184 ;
185 }
186
187 ts_diff = timespec_elapsed(start);
188 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
189 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n",
190 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
191
192 clock_gettime(CLOCK_MONOTONIC, &start);
193 kvm_vm_get_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap);
194
195 ts_diff = timespec_elapsed(start);
196 get_dirty_log_total = timespec_add(get_dirty_log_total,
197 ts_diff);
198 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
199 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
200
201 if (dirty_log_manual_caps) {
202 clock_gettime(CLOCK_MONOTONIC, &start);
203 kvm_vm_clear_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap, 0,
204 host_num_pages);
205
206 ts_diff = timespec_elapsed(start);
207 clear_dirty_log_total = timespec_add(clear_dirty_log_total,
208 ts_diff);
209 pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
210 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
211 }
212 }
213
214 /* Disable dirty logging */
215 clock_gettime(CLOCK_MONOTONIC, &start);
216 vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX, 0);
217 ts_diff = timespec_elapsed(start);
218 pr_info("Disabling dirty logging time: %ld.%.9lds\n",
219 ts_diff.tv_sec, ts_diff.tv_nsec);
220
221 /* Tell the vcpu thread to quit */
222 host_quit = true;
223 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
224 pthread_join(vcpu_threads[vcpu_id], NULL);
225
226 avg = timespec_div(get_dirty_log_total, p->iterations);
227 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
228 p->iterations, get_dirty_log_total.tv_sec,
229 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
230
231 if (dirty_log_manual_caps) {
232 avg = timespec_div(clear_dirty_log_total, p->iterations);
233 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
234 p->iterations, clear_dirty_log_total.tv_sec,
235 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
236 }
237
238 free(bmap);
239 free(vcpu_threads);
240 perf_test_destroy_vm(vm);
241 }
242
help(char * name)243 static void help(char *name)
244 {
245 puts("");
246 printf("usage: %s [-h] [-i iterations] [-p offset] "
247 "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]\n", name);
248 puts("");
249 printf(" -i: specify iteration counts (default: %"PRIu64")\n",
250 TEST_HOST_LOOP_N);
251 printf(" -p: specify guest physical test memory offset\n"
252 " Warning: a low offset can conflict with the loaded test code.\n");
253 guest_modes_help();
254 printf(" -b: specify the size of the memory region which should be\n"
255 " dirtied by each vCPU. e.g. 10M or 3G.\n"
256 " (default: 1G)\n");
257 printf(" -f: specify the fraction of pages which should be written to\n"
258 " as opposed to simply read, in the form\n"
259 " 1/<fraction of pages to write>.\n"
260 " (default: 1 i.e. all pages are written to.)\n");
261 printf(" -v: specify the number of vCPUs to run.\n");
262 printf(" -o: Overlap guest memory accesses instead of partitioning\n"
263 " them into a separate region of memory for each vCPU.\n");
264 printf(" -s: specify the type of memory that should be used to\n"
265 " back the guest data region.\n\n");
266 backing_src_help();
267 puts("");
268 exit(0);
269 }
270
main(int argc,char * argv[])271 int main(int argc, char *argv[])
272 {
273 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
274 struct test_params p = {
275 .iterations = TEST_HOST_LOOP_N,
276 .wr_fract = 1,
277 .partition_vcpu_memory_access = true,
278 .backing_src = VM_MEM_SRC_ANONYMOUS,
279 };
280 int opt;
281
282 dirty_log_manual_caps =
283 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
284 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
285 KVM_DIRTY_LOG_INITIALLY_SET);
286
287 guest_modes_append_default();
288
289 while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:")) != -1) {
290 switch (opt) {
291 case 'i':
292 p.iterations = atoi(optarg);
293 break;
294 case 'p':
295 p.phys_offset = strtoull(optarg, NULL, 0);
296 break;
297 case 'm':
298 guest_modes_cmdline(optarg);
299 break;
300 case 'b':
301 guest_percpu_mem_size = parse_size(optarg);
302 break;
303 case 'f':
304 p.wr_fract = atoi(optarg);
305 TEST_ASSERT(p.wr_fract >= 1,
306 "Write fraction cannot be less than one");
307 break;
308 case 'v':
309 nr_vcpus = atoi(optarg);
310 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
311 "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
312 break;
313 case 'o':
314 p.partition_vcpu_memory_access = false;
315 case 's':
316 p.backing_src = parse_backing_src_type(optarg);
317 break;
318 case 'h':
319 default:
320 help(argv[0]);
321 break;
322 }
323 }
324
325 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations");
326
327 pr_info("Test iterations: %"PRIu64"\n", p.iterations);
328
329 for_each_guest_mode(run_test, &p);
330
331 return 0;
332 }
333