d59820cc2d3981247cd2c2430ad0ef89d11ed2a3
[muen/linux.git] / tools / testing / selftests / kvm / dirty_log_test.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * KVM dirty page logging test
4  *
5  * Copyright (C) 2018, Red Hat, Inc.
6  */
7
8 #define _GNU_SOURCE /* for program_invocation_name */
9
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <unistd.h>
13 #include <time.h>
14 #include <pthread.h>
15 #include <linux/bitmap.h>
16 #include <linux/bitops.h>
17
18 #include "test_util.h"
19 #include "kvm_util.h"
20 #include "processor.h"
21
22 #define DEBUG printf
23
24 #define VCPU_ID                         1
25
26 /* The memory slot index to track dirty pages */
27 #define TEST_MEM_SLOT_INDEX             1
28
29 /* Default guest test memory offset, 1G */
30 #define DEFAULT_GUEST_TEST_MEM          0x40000000
31
32 /* How many pages to dirty for each guest loop */
33 #define TEST_PAGES_PER_LOOP             1024
34
35 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
36 #define TEST_HOST_LOOP_N                32
37
38 /* Interval for each host loop (ms) */
39 #define TEST_HOST_LOOP_INTERVAL         10
40
41 /*
42  * Guest/Host shared variables. Ensure addr_gva2hva() and/or
43  * sync_global_to/from_guest() are used when accessing from
44  * the host. READ/WRITE_ONCE() should also be used with anything
45  * that may change.
46  */
47 static uint64_t host_page_size;
48 static uint64_t guest_page_size;
49 static uint64_t guest_num_pages;
50 static uint64_t random_array[TEST_PAGES_PER_LOOP];
51 static uint64_t iteration;
52
53 /*
54  * GPA offset of the testing memory slot. Must be bigger than
55  * DEFAULT_GUEST_PHY_PAGES.
56  */
57 static uint64_t guest_test_mem = DEFAULT_GUEST_TEST_MEM;
58
59 /*
60  * Continuously write to the first 8 bytes of a random pages within
61  * the testing memory region.
62  */
63 static void guest_code(void)
64 {
65         int i;
66
67         while (true) {
68                 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
69                         uint64_t addr = guest_test_mem;
70                         addr += (READ_ONCE(random_array[i]) % guest_num_pages)
71                                 * guest_page_size;
72                         addr &= ~(host_page_size - 1);
73                         *(uint64_t *)addr = READ_ONCE(iteration);
74                 }
75
76                 /* Tell the host that we need more random numbers */
77                 GUEST_SYNC(1);
78         }
79 }
80
81 /* Host variables */
82 static bool host_quit;
83
84 /* Points to the test VM memory region on which we track dirty logs */
85 static void *host_test_mem;
86 static uint64_t host_num_pages;
87
88 /* For statistics only */
89 static uint64_t host_dirty_count;
90 static uint64_t host_clear_count;
91 static uint64_t host_track_next_count;
92
93 /*
94  * We use this bitmap to track some pages that should have its dirty
95  * bit set in the _next_ iteration.  For example, if we detected the
96  * page value changed to current iteration but at the same time the
97  * page bit is cleared in the latest bitmap, then the system must
98  * report that write in the next get dirty log call.
99  */
100 static unsigned long *host_bmap_track;
101
102 static void generate_random_array(uint64_t *guest_array, uint64_t size)
103 {
104         uint64_t i;
105
106         for (i = 0; i < size; i++)
107                 guest_array[i] = random();
108 }
109
110 static void *vcpu_worker(void *data)
111 {
112         int ret;
113         struct kvm_vm *vm = data;
114         uint64_t *guest_array;
115         uint64_t pages_count = 0;
116         struct kvm_run *run;
117         struct ucall uc;
118
119         run = vcpu_state(vm, VCPU_ID);
120
121         guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
122         generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
123
124         while (!READ_ONCE(host_quit)) {
125                 /* Let the guest dirty the random pages */
126                 ret = _vcpu_run(vm, VCPU_ID);
127                 if (get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) {
128                         pages_count += TEST_PAGES_PER_LOOP;
129                         generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
130                 } else {
131                         TEST_ASSERT(false,
132                                     "Invalid guest sync status: "
133                                     "exit_reason=%s\n",
134                                     exit_reason_str(run->exit_reason));
135                 }
136         }
137
138         DEBUG("Dirtied %"PRIu64" pages\n", pages_count);
139
140         return NULL;
141 }
142
143 static void vm_dirty_log_verify(unsigned long *bmap)
144 {
145         uint64_t page;
146         uint64_t *value_ptr;
147         uint64_t step = host_page_size >= guest_page_size ? 1 :
148                                 guest_page_size / host_page_size;
149
150         for (page = 0; page < host_num_pages; page += step) {
151                 value_ptr = host_test_mem + page * host_page_size;
152
153                 /* If this is a special page that we were tracking... */
154                 if (test_and_clear_bit(page, host_bmap_track)) {
155                         host_track_next_count++;
156                         TEST_ASSERT(test_bit(page, bmap),
157                                     "Page %"PRIu64" should have its dirty bit "
158                                     "set in this iteration but it is missing",
159                                     page);
160                 }
161
162                 if (test_bit(page, bmap)) {
163                         host_dirty_count++;
164                         /*
165                          * If the bit is set, the value written onto
166                          * the corresponding page should be either the
167                          * previous iteration number or the current one.
168                          */
169                         TEST_ASSERT(*value_ptr == iteration ||
170                                     *value_ptr == iteration - 1,
171                                     "Set page %"PRIu64" value %"PRIu64
172                                     " incorrect (iteration=%"PRIu64")",
173                                     page, *value_ptr, iteration);
174                 } else {
175                         host_clear_count++;
176                         /*
177                          * If cleared, the value written can be any
178                          * value smaller or equals to the iteration
179                          * number.  Note that the value can be exactly
180                          * (iteration-1) if that write can happen
181                          * like this:
182                          *
183                          * (1) increase loop count to "iteration-1"
184                          * (2) write to page P happens (with value
185                          *     "iteration-1")
186                          * (3) get dirty log for "iteration-1"; we'll
187                          *     see that page P bit is set (dirtied),
188                          *     and not set the bit in host_bmap_track
189                          * (4) increase loop count to "iteration"
190                          *     (which is current iteration)
191                          * (5) get dirty log for current iteration,
192                          *     we'll see that page P is cleared, with
193                          *     value "iteration-1".
194                          */
195                         TEST_ASSERT(*value_ptr <= iteration,
196                                     "Clear page %"PRIu64" value %"PRIu64
197                                     " incorrect (iteration=%"PRIu64")",
198                                     page, *value_ptr, iteration);
199                         if (*value_ptr == iteration) {
200                                 /*
201                                  * This page is _just_ modified; it
202                                  * should report its dirtyness in the
203                                  * next run
204                                  */
205                                 set_bit(page, host_bmap_track);
206                         }
207                 }
208         }
209 }
210
211 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
212                                 uint64_t extra_mem_pages, void *guest_code)
213 {
214         struct kvm_vm *vm;
215         uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
216
217         vm = vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
218         kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
219 #ifdef __x86_64__
220         vm_create_irqchip(vm);
221 #endif
222         vm_vcpu_add_default(vm, vcpuid, guest_code);
223         return vm;
224 }
225
226 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
227                      unsigned long interval, bool top_offset)
228 {
229         unsigned int guest_pa_bits, guest_page_shift;
230         pthread_t vcpu_thread;
231         struct kvm_vm *vm;
232         uint64_t max_gfn;
233         unsigned long *bmap;
234
235         switch (mode) {
236         case VM_MODE_P52V48_4K:
237                 guest_pa_bits = 52;
238                 guest_page_shift = 12;
239                 break;
240         case VM_MODE_P52V48_64K:
241                 guest_pa_bits = 52;
242                 guest_page_shift = 16;
243                 break;
244         case VM_MODE_P40V48_4K:
245                 guest_pa_bits = 40;
246                 guest_page_shift = 12;
247                 break;
248         case VM_MODE_P40V48_64K:
249                 guest_pa_bits = 40;
250                 guest_page_shift = 16;
251                 break;
252         default:
253                 TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode);
254         }
255
256         DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode));
257
258         max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1;
259         guest_page_size = (1ul << guest_page_shift);
260         /* 1G of guest page sized pages */
261         guest_num_pages = (1ul << (30 - guest_page_shift));
262         host_page_size = getpagesize();
263         host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
264                          !!((guest_num_pages * guest_page_size) % host_page_size);
265
266         if (top_offset) {
267                 guest_test_mem = (max_gfn - guest_num_pages) * guest_page_size;
268                 guest_test_mem &= ~(host_page_size - 1);
269         }
270
271         DEBUG("guest test mem offset: 0x%lx\n", guest_test_mem);
272
273         bmap = bitmap_alloc(host_num_pages);
274         host_bmap_track = bitmap_alloc(host_num_pages);
275
276         vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code);
277
278         /* Add an extra memory slot for testing dirty logging */
279         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
280                                     guest_test_mem,
281                                     TEST_MEM_SLOT_INDEX,
282                                     guest_num_pages,
283                                     KVM_MEM_LOG_DIRTY_PAGES);
284
285         /* Do 1:1 mapping for the dirty track memory slot */
286         virt_map(vm, guest_test_mem, guest_test_mem,
287                  guest_num_pages * guest_page_size, 0);
288
289         /* Cache the HVA pointer of the region */
290         host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_mem);
291
292 #ifdef __x86_64__
293         vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
294 #endif
295 #ifdef __aarch64__
296         ucall_init(vm, UCALL_MMIO, NULL);
297 #endif
298
299         /* Export the shared variables to the guest */
300         sync_global_to_guest(vm, host_page_size);
301         sync_global_to_guest(vm, guest_page_size);
302         sync_global_to_guest(vm, guest_test_mem);
303         sync_global_to_guest(vm, guest_num_pages);
304
305         /* Start the iterations */
306         iteration = 1;
307         sync_global_to_guest(vm, iteration);
308         host_quit = false;
309         host_dirty_count = 0;
310         host_clear_count = 0;
311         host_track_next_count = 0;
312
313         pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
314
315         while (iteration < iterations) {
316                 /* Give the vcpu thread some time to dirty some pages */
317                 usleep(interval * 1000);
318                 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
319                 vm_dirty_log_verify(bmap);
320                 iteration++;
321                 sync_global_to_guest(vm, iteration);
322         }
323
324         /* Tell the vcpu thread to quit */
325         host_quit = true;
326         pthread_join(vcpu_thread, NULL);
327
328         DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
329               "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
330               host_track_next_count);
331
332         free(bmap);
333         free(host_bmap_track);
334         ucall_uninit(vm);
335         kvm_vm_free(vm);
336 }
337
338 static struct vm_guest_modes {
339         enum vm_guest_mode mode;
340         bool supported;
341         bool enabled;
342 } vm_guest_modes[NUM_VM_MODES] = {
343 #if defined(__x86_64__)
344         { VM_MODE_P52V48_4K,    1, 1, },
345         { VM_MODE_P52V48_64K,   0, 0, },
346         { VM_MODE_P40V48_4K,    0, 0, },
347         { VM_MODE_P40V48_64K,   0, 0, },
348 #elif defined(__aarch64__)
349         { VM_MODE_P52V48_4K,    0, 0, },
350         { VM_MODE_P52V48_64K,   0, 0, },
351         { VM_MODE_P40V48_4K,    1, 1, },
352         { VM_MODE_P40V48_64K,   1, 1, },
353 #endif
354 };
355
356 static void help(char *name)
357 {
358         int i;
359
360         puts("");
361         printf("usage: %s [-h] [-i iterations] [-I interval] "
362                "[-o offset] [-t] [-m mode]\n", name);
363         puts("");
364         printf(" -i: specify iteration counts (default: %"PRIu64")\n",
365                TEST_HOST_LOOP_N);
366         printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
367                TEST_HOST_LOOP_INTERVAL);
368         printf(" -o: guest test memory offset (default: 0x%lx)\n",
369                DEFAULT_GUEST_TEST_MEM);
370         printf(" -t: map guest test memory at the top of the allowed "
371                "physical address range\n");
372         printf(" -m: specify the guest mode ID to test "
373                "(default: test all supported modes)\n"
374                "     This option may be used multiple times.\n"
375                "     Guest mode IDs:\n");
376         for (i = 0; i < NUM_VM_MODES; ++i) {
377                 printf("         %d:    %s%s\n",
378                        vm_guest_modes[i].mode,
379                        vm_guest_mode_string(vm_guest_modes[i].mode),
380                        vm_guest_modes[i].supported ? " (supported)" : "");
381         }
382         puts("");
383         exit(0);
384 }
385
386 int main(int argc, char *argv[])
387 {
388         unsigned long iterations = TEST_HOST_LOOP_N;
389         unsigned long interval = TEST_HOST_LOOP_INTERVAL;
390         bool mode_selected = false;
391         bool top_offset = false;
392         unsigned int mode;
393         int opt, i;
394
395         while ((opt = getopt(argc, argv, "hi:I:o:tm:")) != -1) {
396                 switch (opt) {
397                 case 'i':
398                         iterations = strtol(optarg, NULL, 10);
399                         break;
400                 case 'I':
401                         interval = strtol(optarg, NULL, 10);
402                         break;
403                 case 'o':
404                         guest_test_mem = strtoull(optarg, NULL, 0);
405                         break;
406                 case 't':
407                         top_offset = true;
408                         break;
409                 case 'm':
410                         if (!mode_selected) {
411                                 for (i = 0; i < NUM_VM_MODES; ++i)
412                                         vm_guest_modes[i].enabled = 0;
413                                 mode_selected = true;
414                         }
415                         mode = strtoul(optarg, NULL, 10);
416                         TEST_ASSERT(mode < NUM_VM_MODES,
417                                     "Guest mode ID %d too big", mode);
418                         vm_guest_modes[mode].enabled = 1;
419                         break;
420                 case 'h':
421                 default:
422                         help(argv[0]);
423                         break;
424                 }
425         }
426
427         TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
428         TEST_ASSERT(interval > 0, "Interval must be greater than zero");
429         TEST_ASSERT(!top_offset || guest_test_mem == DEFAULT_GUEST_TEST_MEM,
430                     "Cannot use both -o [offset] and -t at the same time");
431
432         DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
433               iterations, interval);
434
435         srandom(time(0));
436
437         for (i = 0; i < NUM_VM_MODES; ++i) {
438                 if (!vm_guest_modes[i].enabled)
439                         continue;
440                 TEST_ASSERT(vm_guest_modes[i].supported,
441                             "Guest mode ID %d (%s) not supported.",
442                             vm_guest_modes[i].mode,
443                             vm_guest_mode_string(vm_guest_modes[i].mode));
444                 run_test(vm_guest_modes[i].mode, iterations, interval, top_offset);
445         }
446
447         return 0;
448 }