1 // SPDX-License-Identifier: GPL-2.0
3 * KVM dirty page logging test
5 * Copyright (C) 2018, Red Hat, Inc.
8 #define _GNU_SOURCE /* for program_invocation_name */
15 #include <linux/bitmap.h>
16 #include <linux/bitops.h>
18 #include "test_util.h"
20 #include "processor.h"
24 /* The memory slot index to track dirty pages */
25 #define TEST_MEM_SLOT_INDEX 1
27 /* Default guest test virtual memory offset */
28 #define DEFAULT_GUEST_TEST_MEM 0xc0000000
30 /* How many pages to dirty for each guest loop */
31 #define TEST_PAGES_PER_LOOP 1024
33 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
34 #define TEST_HOST_LOOP_N 32UL
36 /* Interval for each host loop (ms) */
37 #define TEST_HOST_LOOP_INTERVAL 10UL
39 /* Dirty bitmaps are always little endian, so we need to swap on big endian */
40 #if defined(__s390x__)
41 # define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7)
42 # define test_bit_le(nr, addr) \
43 test_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
44 # define set_bit_le(nr, addr) \
45 set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
46 # define clear_bit_le(nr, addr) \
47 clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
48 # define test_and_set_bit_le(nr, addr) \
49 test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
50 # define test_and_clear_bit_le(nr, addr) \
51 test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
53 # define test_bit_le test_bit
54 # define set_bit_le set_bit
55 # define clear_bit_le clear_bit
56 # define test_and_set_bit_le test_and_set_bit
57 # define test_and_clear_bit_le test_and_clear_bit
61 * Guest/Host shared variables. Ensure addr_gva2hva() and/or
62 * sync_global_to/from_guest() are used when accessing from
63 * the host. READ/WRITE_ONCE() should also be used with anything
66 static uint64_t host_page_size;
67 static uint64_t guest_page_size;
68 static uint64_t guest_num_pages;
69 static uint64_t random_array[TEST_PAGES_PER_LOOP];
70 static uint64_t iteration;
73 * Guest physical memory offset of the testing memory slot.
74 * This will be set to the topmost valid physical address minus
75 * the test memory size.
77 static uint64_t guest_test_phys_mem;
80 * Guest virtual memory offset of the testing memory slot.
81 * Must not conflict with identity mapped test code.
83 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
86 * Continuously write to the first 8 bytes of a random pages within
87 * the testing memory region.
89 static void guest_code(void)
95 * On s390x, all pages of a 1M segment are initially marked as dirty
96 * when a page of the segment is written to for the very first time.
97 * To compensate this specialty in this test, we need to touch all
98 * pages during the first iteration.
100 for (i = 0; i < guest_num_pages; i++) {
101 addr = guest_test_virt_mem + i * guest_page_size;
102 *(uint64_t *)addr = READ_ONCE(iteration);
106 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
107 addr = guest_test_virt_mem;
108 addr += (READ_ONCE(random_array[i]) % guest_num_pages)
110 addr &= ~(host_page_size - 1);
111 *(uint64_t *)addr = READ_ONCE(iteration);
114 /* Tell the host that we need more random numbers */
120 static bool host_quit;
122 /* Points to the test VM memory region on which we track dirty logs */
123 static void *host_test_mem;
124 static uint64_t host_num_pages;
126 /* For statistics only */
127 static uint64_t host_dirty_count;
128 static uint64_t host_clear_count;
129 static uint64_t host_track_next_count;
132 * We use this bitmap to track some pages that should have its dirty
133 * bit set in the _next_ iteration. For example, if we detected the
134 * page value changed to current iteration but at the same time the
135 * page bit is cleared in the latest bitmap, then the system must
136 * report that write in the next get dirty log call.
138 static unsigned long *host_bmap_track;
140 static void generate_random_array(uint64_t *guest_array, uint64_t size)
144 for (i = 0; i < size; i++)
145 guest_array[i] = random();
148 static void *vcpu_worker(void *data)
151 struct kvm_vm *vm = data;
152 uint64_t *guest_array;
153 uint64_t pages_count = 0;
156 run = vcpu_state(vm, VCPU_ID);
158 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
159 generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
161 while (!READ_ONCE(host_quit)) {
162 /* Let the guest dirty the random pages */
163 ret = _vcpu_run(vm, VCPU_ID);
164 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
165 if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
166 pages_count += TEST_PAGES_PER_LOOP;
167 generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
170 "Invalid guest sync status: "
172 exit_reason_str(run->exit_reason));
176 pr_info("Dirtied %"PRIu64" pages\n", pages_count);
181 static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap)
183 uint64_t step = vm_num_host_pages(mode, 1);
187 for (page = 0; page < host_num_pages; page += step) {
188 value_ptr = host_test_mem + page * host_page_size;
190 /* If this is a special page that we were tracking... */
191 if (test_and_clear_bit_le(page, host_bmap_track)) {
192 host_track_next_count++;
193 TEST_ASSERT(test_bit_le(page, bmap),
194 "Page %"PRIu64" should have its dirty bit "
195 "set in this iteration but it is missing",
199 if (test_bit_le(page, bmap)) {
202 * If the bit is set, the value written onto
203 * the corresponding page should be either the
204 * previous iteration number or the current one.
206 TEST_ASSERT(*value_ptr == iteration ||
207 *value_ptr == iteration - 1,
208 "Set page %"PRIu64" value %"PRIu64
209 " incorrect (iteration=%"PRIu64")",
210 page, *value_ptr, iteration);
214 * If cleared, the value written can be any
215 * value smaller or equals to the iteration
216 * number. Note that the value can be exactly
217 * (iteration-1) if that write can happen
220 * (1) increase loop count to "iteration-1"
221 * (2) write to page P happens (with value
223 * (3) get dirty log for "iteration-1"; we'll
224 * see that page P bit is set (dirtied),
225 * and not set the bit in host_bmap_track
226 * (4) increase loop count to "iteration"
227 * (which is current iteration)
228 * (5) get dirty log for current iteration,
229 * we'll see that page P is cleared, with
230 * value "iteration-1".
232 TEST_ASSERT(*value_ptr <= iteration,
233 "Clear page %"PRIu64" value %"PRIu64
234 " incorrect (iteration=%"PRIu64")",
235 page, *value_ptr, iteration);
236 if (*value_ptr == iteration) {
238 * This page is _just_ modified; it
239 * should report its dirtyness in the
242 set_bit_le(page, host_bmap_track);
248 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
249 uint64_t extra_mem_pages, void *guest_code)
252 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
254 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
256 vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
257 kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
259 vm_create_irqchip(vm);
261 vm_vcpu_add_default(vm, vcpuid, guest_code);
265 #define DIRTY_MEM_BITS 30 /* 1G */
266 #define PAGE_SHIFT_4K 12
268 #ifdef USE_CLEAR_DIRTY_LOG
269 static u64 dirty_log_manual_caps;
272 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
273 unsigned long interval, uint64_t phys_offset)
275 pthread_t vcpu_thread;
280 * We reserve page table for 2 times of extra dirty mem which
281 * will definitely cover the original (1G+) test range. Here
282 * we do the calculation with 4K page size which is the
283 * smallest so the page number will be enough for all archs
284 * (e.g., 64K page size guest will need even less memory for
287 vm = create_vm(mode, VCPU_ID,
288 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K),
291 guest_page_size = vm_get_page_size(vm);
293 * A little more than 1G of guest page sized pages. Cover the
294 * case where the size is not aligned to 64 pages.
296 guest_num_pages = (1ul << (DIRTY_MEM_BITS -
297 vm_get_page_shift(vm))) + 3;
298 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
300 host_page_size = getpagesize();
301 host_num_pages = vm_num_host_pages(mode, guest_num_pages);
304 guest_test_phys_mem = (vm_get_max_gfn(vm) -
305 guest_num_pages) * guest_page_size;
306 guest_test_phys_mem &= ~(host_page_size - 1);
308 guest_test_phys_mem = phys_offset;
312 /* Align to 1M (segment size) */
313 guest_test_phys_mem &= ~((1 << 20) - 1);
316 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
318 bmap = bitmap_alloc(host_num_pages);
319 host_bmap_track = bitmap_alloc(host_num_pages);
321 #ifdef USE_CLEAR_DIRTY_LOG
322 struct kvm_enable_cap cap = {};
324 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
325 cap.args[0] = dirty_log_manual_caps;
326 vm_enable_cap(vm, &cap);
329 /* Add an extra memory slot for testing dirty logging */
330 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
334 KVM_MEM_LOG_DIRTY_PAGES);
336 /* Do mapping for the dirty track memory slot */
337 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
338 guest_num_pages * guest_page_size, 0);
340 /* Cache the HVA pointer of the region */
341 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
344 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
346 ucall_init(vm, NULL);
348 /* Export the shared variables to the guest */
349 sync_global_to_guest(vm, host_page_size);
350 sync_global_to_guest(vm, guest_page_size);
351 sync_global_to_guest(vm, guest_test_virt_mem);
352 sync_global_to_guest(vm, guest_num_pages);
354 /* Start the iterations */
356 sync_global_to_guest(vm, iteration);
358 host_dirty_count = 0;
359 host_clear_count = 0;
360 host_track_next_count = 0;
362 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
364 while (iteration < iterations) {
365 /* Give the vcpu thread some time to dirty some pages */
366 usleep(interval * 1000);
367 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
368 #ifdef USE_CLEAR_DIRTY_LOG
369 kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
372 vm_dirty_log_verify(mode, bmap);
374 sync_global_to_guest(vm, iteration);
377 /* Tell the vcpu thread to quit */
379 pthread_join(vcpu_thread, NULL);
381 pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
382 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
383 host_track_next_count);
386 free(host_bmap_track);
395 static struct guest_mode guest_modes[NUM_VM_MODES];
397 #define guest_mode_init(mode, supported, enabled) ({ \
398 guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
401 static void help(char *name)
406 printf("usage: %s [-h] [-i iterations] [-I interval] "
407 "[-p offset] [-m mode]\n", name);
409 printf(" -i: specify iteration counts (default: %"PRIu64")\n",
411 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
412 TEST_HOST_LOOP_INTERVAL);
413 printf(" -p: specify guest physical test memory offset\n"
414 " Warning: a low offset can conflict with the loaded test code.\n");
415 printf(" -m: specify the guest mode ID to test "
416 "(default: test all supported modes)\n"
417 " This option may be used multiple times.\n"
418 " Guest mode IDs:\n");
419 for (i = 0; i < NUM_VM_MODES; ++i) {
420 printf(" %d: %s%s\n", i, vm_guest_mode_string(i),
421 guest_modes[i].supported ? " (supported)" : "");
427 int main(int argc, char *argv[])
429 unsigned long iterations = TEST_HOST_LOOP_N;
430 unsigned long interval = TEST_HOST_LOOP_INTERVAL;
431 bool mode_selected = false;
432 uint64_t phys_offset = 0;
436 #ifdef USE_CLEAR_DIRTY_LOG
437 dirty_log_manual_caps =
438 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
439 if (!dirty_log_manual_caps) {
440 fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, "
444 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
445 KVM_DIRTY_LOG_INITIALLY_SET);
449 guest_mode_init(VM_MODE_PXXV48_4K, true, true);
452 guest_mode_init(VM_MODE_P40V48_4K, true, true);
453 guest_mode_init(VM_MODE_P40V48_64K, true, true);
456 unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
459 guest_mode_init(VM_MODE_P52V48_64K, true, true);
461 guest_mode_init(VM_MODE_P48V48_4K, true, true);
462 guest_mode_init(VM_MODE_P48V48_64K, true, true);
467 guest_mode_init(VM_MODE_P40V48_4K, true, true);
470 while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
473 iterations = strtol(optarg, NULL, 10);
476 interval = strtol(optarg, NULL, 10);
479 phys_offset = strtoull(optarg, NULL, 0);
482 if (!mode_selected) {
483 for (i = 0; i < NUM_VM_MODES; ++i)
484 guest_modes[i].enabled = false;
485 mode_selected = true;
487 mode = strtoul(optarg, NULL, 10);
488 TEST_ASSERT(mode < NUM_VM_MODES,
489 "Guest mode ID %d too big", mode);
490 guest_modes[mode].enabled = true;
499 TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
500 TEST_ASSERT(interval > 0, "Interval must be greater than zero");
502 pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
503 iterations, interval);
507 for (i = 0; i < NUM_VM_MODES; ++i) {
508 if (!guest_modes[i].enabled)
510 TEST_ASSERT(guest_modes[i].supported,
511 "Guest mode ID %d (%s) not supported.",
512 i, vm_guest_mode_string(i));
513 run_test(i, iterations, interval, phys_offset);