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(struct perf_test_vcpu_args * vcpu_args)34 static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
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 int vcpu_id = vcpu_args->vcpu_id;
45
46 run = vcpu_state(vm, vcpu_id);
47
48 while (!READ_ONCE(host_quit)) {
49 int current_iteration = READ_ONCE(iteration);
50
51 clock_gettime(CLOCK_MONOTONIC, &start);
52 ret = _vcpu_run(vm, vcpu_id);
53 ts_diff = timespec_elapsed(start);
54
55 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
56 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
57 "Invalid guest sync status: exit_reason=%s\n",
58 exit_reason_str(run->exit_reason));
59
60 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
61 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
62 pr_debug("vCPU %d updated last completed iteration to %d\n",
63 vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
64
65 if (current_iteration) {
66 pages_count += vcpu_args->pages;
67 total = timespec_add(total, ts_diff);
68 pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
69 vcpu_id, current_iteration, ts_diff.tv_sec,
70 ts_diff.tv_nsec);
71 } else {
72 pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
73 vcpu_id, current_iteration, ts_diff.tv_sec,
74 ts_diff.tv_nsec);
75 }
76
77 while (current_iteration == READ_ONCE(iteration) &&
78 !READ_ONCE(host_quit)) {}
79 }
80
81 avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
82 pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
83 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
84 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
85 }
86
87 struct test_params {
88 unsigned long iterations;
89 uint64_t phys_offset;
90 int wr_fract;
91 bool partition_vcpu_memory_access;
92 enum vm_mem_backing_src_type backing_src;
93 int slots;
94 };
95
toggle_dirty_logging(struct kvm_vm * vm,int slots,bool enable)96 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
97 {
98 int i;
99
100 for (i = 0; i < slots; i++) {
101 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
102 int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
103
104 vm_mem_region_set_flags(vm, slot, flags);
105 }
106 }
107
enable_dirty_logging(struct kvm_vm * vm,int slots)108 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
109 {
110 toggle_dirty_logging(vm, slots, true);
111 }
112
disable_dirty_logging(struct kvm_vm * vm,int slots)113 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
114 {
115 toggle_dirty_logging(vm, slots, false);
116 }
117
get_dirty_log(struct kvm_vm * vm,unsigned long * bitmaps[],int slots)118 static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots)
119 {
120 int i;
121
122 for (i = 0; i < slots; i++) {
123 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
124
125 kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
126 }
127 }
128
clear_dirty_log(struct kvm_vm * vm,unsigned long * bitmaps[],int slots,uint64_t pages_per_slot)129 static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
130 int slots, uint64_t pages_per_slot)
131 {
132 int i;
133
134 for (i = 0; i < slots; i++) {
135 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
136
137 kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
138 }
139 }
140
alloc_bitmaps(int slots,uint64_t pages_per_slot)141 static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot)
142 {
143 unsigned long **bitmaps;
144 int i;
145
146 bitmaps = malloc(slots * sizeof(bitmaps[0]));
147 TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array.");
148
149 for (i = 0; i < slots; i++) {
150 bitmaps[i] = bitmap_zalloc(pages_per_slot);
151 TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap.");
152 }
153
154 return bitmaps;
155 }
156
free_bitmaps(unsigned long * bitmaps[],int slots)157 static void free_bitmaps(unsigned long *bitmaps[], int slots)
158 {
159 int i;
160
161 for (i = 0; i < slots; i++)
162 free(bitmaps[i]);
163
164 free(bitmaps);
165 }
166
run_test(enum vm_guest_mode mode,void * arg)167 static void run_test(enum vm_guest_mode mode, void *arg)
168 {
169 struct test_params *p = arg;
170 struct kvm_vm *vm;
171 unsigned long **bitmaps;
172 uint64_t guest_num_pages;
173 uint64_t host_num_pages;
174 uint64_t pages_per_slot;
175 int vcpu_id;
176 struct timespec start;
177 struct timespec ts_diff;
178 struct timespec get_dirty_log_total = (struct timespec){0};
179 struct timespec vcpu_dirty_total = (struct timespec){0};
180 struct timespec avg;
181 struct kvm_enable_cap cap = {};
182 struct timespec clear_dirty_log_total = (struct timespec){0};
183
184 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
185 p->slots, p->backing_src,
186 p->partition_vcpu_memory_access);
187
188 perf_test_set_wr_fract(vm, p->wr_fract);
189
190 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
191 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
192 host_num_pages = vm_num_host_pages(mode, guest_num_pages);
193 pages_per_slot = host_num_pages / p->slots;
194
195 bitmaps = alloc_bitmaps(p->slots, pages_per_slot);
196
197 if (dirty_log_manual_caps) {
198 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
199 cap.args[0] = dirty_log_manual_caps;
200 vm_enable_cap(vm, &cap);
201 }
202
203 /* Start the iterations */
204 iteration = 0;
205 host_quit = false;
206
207 clock_gettime(CLOCK_MONOTONIC, &start);
208 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
209 vcpu_last_completed_iteration[vcpu_id] = -1;
210
211 perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
212
213 /* Allow the vCPUs to populate memory */
214 pr_debug("Starting iteration %d - Populating\n", iteration);
215 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
216 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
217 iteration)
218 ;
219 }
220
221 ts_diff = timespec_elapsed(start);
222 pr_info("Populate memory time: %ld.%.9lds\n",
223 ts_diff.tv_sec, ts_diff.tv_nsec);
224
225 /* Enable dirty logging */
226 clock_gettime(CLOCK_MONOTONIC, &start);
227 enable_dirty_logging(vm, p->slots);
228 ts_diff = timespec_elapsed(start);
229 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
230 ts_diff.tv_sec, ts_diff.tv_nsec);
231
232 while (iteration < p->iterations) {
233 /*
234 * Incrementing the iteration number will start the vCPUs
235 * dirtying memory again.
236 */
237 clock_gettime(CLOCK_MONOTONIC, &start);
238 iteration++;
239
240 pr_debug("Starting iteration %d\n", iteration);
241 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
242 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
243 != iteration)
244 ;
245 }
246
247 ts_diff = timespec_elapsed(start);
248 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
249 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n",
250 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
251
252 clock_gettime(CLOCK_MONOTONIC, &start);
253 get_dirty_log(vm, bitmaps, p->slots);
254 ts_diff = timespec_elapsed(start);
255 get_dirty_log_total = timespec_add(get_dirty_log_total,
256 ts_diff);
257 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
258 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
259
260 if (dirty_log_manual_caps) {
261 clock_gettime(CLOCK_MONOTONIC, &start);
262 clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot);
263 ts_diff = timespec_elapsed(start);
264 clear_dirty_log_total = timespec_add(clear_dirty_log_total,
265 ts_diff);
266 pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
267 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
268 }
269 }
270
271 /* Disable dirty logging */
272 clock_gettime(CLOCK_MONOTONIC, &start);
273 disable_dirty_logging(vm, p->slots);
274 ts_diff = timespec_elapsed(start);
275 pr_info("Disabling dirty logging time: %ld.%.9lds\n",
276 ts_diff.tv_sec, ts_diff.tv_nsec);
277
278 /* Tell the vcpu thread to quit */
279 host_quit = true;
280 perf_test_join_vcpu_threads(nr_vcpus);
281
282 avg = timespec_div(get_dirty_log_total, p->iterations);
283 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
284 p->iterations, get_dirty_log_total.tv_sec,
285 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
286
287 if (dirty_log_manual_caps) {
288 avg = timespec_div(clear_dirty_log_total, p->iterations);
289 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
290 p->iterations, clear_dirty_log_total.tv_sec,
291 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
292 }
293
294 free_bitmaps(bitmaps, p->slots);
295 perf_test_destroy_vm(vm);
296 }
297
help(char * name)298 static void help(char *name)
299 {
300 puts("");
301 printf("usage: %s [-h] [-i iterations] [-p offset] "
302 "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
303 "[-x memslots]\n", name);
304 puts("");
305 printf(" -i: specify iteration counts (default: %"PRIu64")\n",
306 TEST_HOST_LOOP_N);
307 printf(" -p: specify guest physical test memory offset\n"
308 " Warning: a low offset can conflict with the loaded test code.\n");
309 guest_modes_help();
310 printf(" -b: specify the size of the memory region which should be\n"
311 " dirtied by each vCPU. e.g. 10M or 3G.\n"
312 " (default: 1G)\n");
313 printf(" -f: specify the fraction of pages which should be written to\n"
314 " as opposed to simply read, in the form\n"
315 " 1/<fraction of pages to write>.\n"
316 " (default: 1 i.e. all pages are written to.)\n");
317 printf(" -v: specify the number of vCPUs to run.\n");
318 printf(" -o: Overlap guest memory accesses instead of partitioning\n"
319 " them into a separate region of memory for each vCPU.\n");
320 backing_src_help("-s");
321 printf(" -x: Split the memory region into this number of memslots.\n"
322 " (default: 1)\n");
323 puts("");
324 exit(0);
325 }
326
main(int argc,char * argv[])327 int main(int argc, char *argv[])
328 {
329 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
330 struct test_params p = {
331 .iterations = TEST_HOST_LOOP_N,
332 .wr_fract = 1,
333 .partition_vcpu_memory_access = true,
334 .backing_src = DEFAULT_VM_MEM_SRC,
335 .slots = 1,
336 };
337 int opt;
338
339 dirty_log_manual_caps =
340 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
341 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
342 KVM_DIRTY_LOG_INITIALLY_SET);
343
344 guest_modes_append_default();
345
346 while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:x:")) != -1) {
347 switch (opt) {
348 case 'i':
349 p.iterations = atoi(optarg);
350 break;
351 case 'p':
352 p.phys_offset = strtoull(optarg, NULL, 0);
353 break;
354 case 'm':
355 guest_modes_cmdline(optarg);
356 break;
357 case 'b':
358 guest_percpu_mem_size = parse_size(optarg);
359 break;
360 case 'f':
361 p.wr_fract = atoi(optarg);
362 TEST_ASSERT(p.wr_fract >= 1,
363 "Write fraction cannot be less than one");
364 break;
365 case 'v':
366 nr_vcpus = atoi(optarg);
367 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
368 "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
369 break;
370 case 'o':
371 p.partition_vcpu_memory_access = false;
372 break;
373 case 's':
374 p.backing_src = parse_backing_src_type(optarg);
375 break;
376 case 'x':
377 p.slots = atoi(optarg);
378 break;
379 case 'h':
380 default:
381 help(argv[0]);
382 break;
383 }
384 }
385
386 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations");
387
388 pr_info("Test iterations: %"PRIu64"\n", p.iterations);
389
390 for_each_guest_mode(run_test, &p);
391
392 return 0;
393 }
394