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);
169 TEST_FAIL("Invalid guest sync status: "
171 exit_reason_str(run->exit_reason));
175 pr_info("Dirtied %"PRIu64" pages\n", pages_count);
180 static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap)
182 uint64_t step = vm_num_host_pages(mode, 1);
186 for (page = 0; page < host_num_pages; page += step) {
187 value_ptr = host_test_mem + page * host_page_size;
189 /* If this is a special page that we were tracking... */
190 if (test_and_clear_bit_le(page, host_bmap_track)) {
191 host_track_next_count++;
192 TEST_ASSERT(test_bit_le(page, bmap),
193 "Page %"PRIu64" should have its dirty bit "
194 "set in this iteration but it is missing",
198 if (test_bit_le(page, bmap)) {
201 * If the bit is set, the value written onto
202 * the corresponding page should be either the
203 * previous iteration number or the current one.
205 TEST_ASSERT(*value_ptr == iteration ||
206 *value_ptr == iteration - 1,
207 "Set page %"PRIu64" value %"PRIu64
208 " incorrect (iteration=%"PRIu64")",
209 page, *value_ptr, iteration);
213 * If cleared, the value written can be any
214 * value smaller or equals to the iteration
215 * number. Note that the value can be exactly
216 * (iteration-1) if that write can happen
219 * (1) increase loop count to "iteration-1"
220 * (2) write to page P happens (with value
222 * (3) get dirty log for "iteration-1"; we'll
223 * see that page P bit is set (dirtied),
224 * and not set the bit in host_bmap_track
225 * (4) increase loop count to "iteration"
226 * (which is current iteration)
227 * (5) get dirty log for current iteration,
228 * we'll see that page P is cleared, with
229 * value "iteration-1".
231 TEST_ASSERT(*value_ptr <= iteration,
232 "Clear page %"PRIu64" value %"PRIu64
233 " incorrect (iteration=%"PRIu64")",
234 page, *value_ptr, iteration);
235 if (*value_ptr == iteration) {
237 * This page is _just_ modified; it
238 * should report its dirtyness in the
241 set_bit_le(page, host_bmap_track);
247 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
248 uint64_t extra_mem_pages, void *guest_code)
251 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
253 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
255 vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
256 kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
258 vm_create_irqchip(vm);
260 vm_vcpu_add_default(vm, vcpuid, guest_code);
264 #define DIRTY_MEM_BITS 30 /* 1G */
265 #define PAGE_SHIFT_4K 12
267 #ifdef USE_CLEAR_DIRTY_LOG
268 static u64 dirty_log_manual_caps;
271 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
272 unsigned long interval, uint64_t phys_offset)
274 pthread_t vcpu_thread;
279 * We reserve page table for 2 times of extra dirty mem which
280 * will definitely cover the original (1G+) test range. Here
281 * we do the calculation with 4K page size which is the
282 * smallest so the page number will be enough for all archs
283 * (e.g., 64K page size guest will need even less memory for
286 vm = create_vm(mode, VCPU_ID,
287 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K),
290 guest_page_size = vm_get_page_size(vm);
292 * A little more than 1G of guest page sized pages. Cover the
293 * case where the size is not aligned to 64 pages.
295 guest_num_pages = (1ul << (DIRTY_MEM_BITS -
296 vm_get_page_shift(vm))) + 3;
297 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
299 host_page_size = getpagesize();
300 host_num_pages = vm_num_host_pages(mode, guest_num_pages);
303 guest_test_phys_mem = (vm_get_max_gfn(vm) -
304 guest_num_pages) * guest_page_size;
305 guest_test_phys_mem &= ~(host_page_size - 1);
307 guest_test_phys_mem = phys_offset;
311 /* Align to 1M (segment size) */
312 guest_test_phys_mem &= ~((1 << 20) - 1);
315 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
317 bmap = bitmap_alloc(host_num_pages);
318 host_bmap_track = bitmap_alloc(host_num_pages);
320 #ifdef USE_CLEAR_DIRTY_LOG
321 struct kvm_enable_cap cap = {};
323 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
324 cap.args[0] = dirty_log_manual_caps;
325 vm_enable_cap(vm, &cap);
328 /* Add an extra memory slot for testing dirty logging */
329 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
333 KVM_MEM_LOG_DIRTY_PAGES);
335 /* Do mapping for the dirty track memory slot */
336 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
338 /* Cache the HVA pointer of the region */
339 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
342 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
344 ucall_init(vm, NULL);
346 /* Export the shared variables to the guest */
347 sync_global_to_guest(vm, host_page_size);
348 sync_global_to_guest(vm, guest_page_size);
349 sync_global_to_guest(vm, guest_test_virt_mem);
350 sync_global_to_guest(vm, guest_num_pages);
352 /* Start the iterations */
354 sync_global_to_guest(vm, iteration);
356 host_dirty_count = 0;
357 host_clear_count = 0;
358 host_track_next_count = 0;
360 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
362 while (iteration < iterations) {
363 /* Give the vcpu thread some time to dirty some pages */
364 usleep(interval * 1000);
365 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
366 #ifdef USE_CLEAR_DIRTY_LOG
367 kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
370 vm_dirty_log_verify(mode, bmap);
372 sync_global_to_guest(vm, iteration);
375 /* Tell the vcpu thread to quit */
377 pthread_join(vcpu_thread, NULL);
379 pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
380 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
381 host_track_next_count);
384 free(host_bmap_track);
393 static struct guest_mode guest_modes[NUM_VM_MODES];
395 #define guest_mode_init(mode, supported, enabled) ({ \
396 guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
399 static void help(char *name)
404 printf("usage: %s [-h] [-i iterations] [-I interval] "
405 "[-p offset] [-m mode]\n", name);
407 printf(" -i: specify iteration counts (default: %"PRIu64")\n",
409 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
410 TEST_HOST_LOOP_INTERVAL);
411 printf(" -p: specify guest physical test memory offset\n"
412 " Warning: a low offset can conflict with the loaded test code.\n");
413 printf(" -m: specify the guest mode ID to test "
414 "(default: test all supported modes)\n"
415 " This option may be used multiple times.\n"
416 " Guest mode IDs:\n");
417 for (i = 0; i < NUM_VM_MODES; ++i) {
418 printf(" %d: %s%s\n", i, vm_guest_mode_string(i),
419 guest_modes[i].supported ? " (supported)" : "");
425 int main(int argc, char *argv[])
427 unsigned long iterations = TEST_HOST_LOOP_N;
428 unsigned long interval = TEST_HOST_LOOP_INTERVAL;
429 bool mode_selected = false;
430 uint64_t phys_offset = 0;
434 #ifdef USE_CLEAR_DIRTY_LOG
435 dirty_log_manual_caps =
436 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
437 if (!dirty_log_manual_caps) {
438 print_skip("KVM_CLEAR_DIRTY_LOG not available");
441 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
442 KVM_DIRTY_LOG_INITIALLY_SET);
446 guest_mode_init(VM_MODE_PXXV48_4K, true, true);
449 guest_mode_init(VM_MODE_P40V48_4K, true, true);
450 guest_mode_init(VM_MODE_P40V48_64K, true, true);
453 unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
456 guest_mode_init(VM_MODE_P52V48_64K, true, true);
458 guest_mode_init(VM_MODE_P48V48_4K, true, true);
459 guest_mode_init(VM_MODE_P48V48_64K, true, true);
464 guest_mode_init(VM_MODE_P40V48_4K, true, true);
467 while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
470 iterations = strtol(optarg, NULL, 10);
473 interval = strtol(optarg, NULL, 10);
476 phys_offset = strtoull(optarg, NULL, 0);
479 if (!mode_selected) {
480 for (i = 0; i < NUM_VM_MODES; ++i)
481 guest_modes[i].enabled = false;
482 mode_selected = true;
484 mode = strtoul(optarg, NULL, 10);
485 TEST_ASSERT(mode < NUM_VM_MODES,
486 "Guest mode ID %d too big", mode);
487 guest_modes[mode].enabled = true;
496 TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
497 TEST_ASSERT(interval > 0, "Interval must be greater than zero");
499 pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
500 iterations, interval);
504 for (i = 0; i < NUM_VM_MODES; ++i) {
505 if (!guest_modes[i].enabled)
507 TEST_ASSERT(guest_modes[i].supported,
508 "Guest mode ID %d (%s) not supported.",
509 i, vm_guest_mode_string(i));
510 run_test(i, iterations, interval, phys_offset);