diff options
Diffstat (limited to 'tools/testing/selftests/kvm/dirty_log_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/dirty_log_test.c | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c new file mode 100644 index 000000000..54da9cc20 --- /dev/null +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -0,0 +1,639 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM dirty page logging test + * + * Copyright (C) 2018, Red Hat, Inc. + */ + +#define _GNU_SOURCE /* for program_invocation_name */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <time.h> +#include <pthread.h> +#include <linux/bitmap.h> +#include <linux/bitops.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" + +#define VCPU_ID 1 + +/* The memory slot index to track dirty pages */ +#define TEST_MEM_SLOT_INDEX 1 + +/* Default guest test virtual memory offset */ +#define DEFAULT_GUEST_TEST_MEM 0xc0000000 + +/* How many pages to dirty for each guest loop */ +#define TEST_PAGES_PER_LOOP 1024 + +/* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */ +#define TEST_HOST_LOOP_N 32UL + +/* Interval for each host loop (ms) */ +#define TEST_HOST_LOOP_INTERVAL 10UL + +/* Dirty bitmaps are always little endian, so we need to swap on big endian */ +#if defined(__s390x__) +# define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) +# define test_bit_le(nr, addr) \ + test_bit((nr) ^ BITOP_LE_SWIZZLE, addr) +# define set_bit_le(nr, addr) \ + set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) +# define clear_bit_le(nr, addr) \ + clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) +# define test_and_set_bit_le(nr, addr) \ + test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) +# define test_and_clear_bit_le(nr, addr) \ + test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) +#else +# define test_bit_le test_bit +# define set_bit_le set_bit +# define clear_bit_le clear_bit +# define test_and_set_bit_le test_and_set_bit +# define test_and_clear_bit_le test_and_clear_bit +#endif + +/* + * Guest/Host shared variables. Ensure addr_gva2hva() and/or + * sync_global_to/from_guest() are used when accessing from + * the host. READ/WRITE_ONCE() should also be used with anything + * that may change. + */ +static uint64_t host_page_size; +static uint64_t guest_page_size; +static uint64_t guest_num_pages; +static uint64_t random_array[TEST_PAGES_PER_LOOP]; +static uint64_t iteration; + +/* + * Guest physical memory offset of the testing memory slot. + * This will be set to the topmost valid physical address minus + * the test memory size. + */ +static uint64_t guest_test_phys_mem; + +/* + * Guest virtual memory offset of the testing memory slot. + * Must not conflict with identity mapped test code. + */ +static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; + +/* + * Continuously write to the first 8 bytes of a random pages within + * the testing memory region. + */ +static void guest_code(void) +{ + uint64_t addr; + int i; + + /* + * On s390x, all pages of a 1M segment are initially marked as dirty + * when a page of the segment is written to for the very first time. + * To compensate this specialty in this test, we need to touch all + * pages during the first iteration. + */ + for (i = 0; i < guest_num_pages; i++) { + addr = guest_test_virt_mem + i * guest_page_size; + *(uint64_t *)addr = READ_ONCE(iteration); + } + + while (true) { + for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { + addr = guest_test_virt_mem; + addr += (READ_ONCE(random_array[i]) % guest_num_pages) + * guest_page_size; + addr &= ~(host_page_size - 1); + *(uint64_t *)addr = READ_ONCE(iteration); + } + + /* Tell the host that we need more random numbers */ + GUEST_SYNC(1); + } +} + +/* Host variables */ +static bool host_quit; + +/* Points to the test VM memory region on which we track dirty logs */ +static void *host_test_mem; +static uint64_t host_num_pages; + +/* For statistics only */ +static uint64_t host_dirty_count; +static uint64_t host_clear_count; +static uint64_t host_track_next_count; + +enum log_mode_t { + /* Only use KVM_GET_DIRTY_LOG for logging */ + LOG_MODE_DIRTY_LOG = 0, + + /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */ + LOG_MODE_CLEAR_LOG = 1, + + LOG_MODE_NUM, + + /* Run all supported modes */ + LOG_MODE_ALL = LOG_MODE_NUM, +}; + +/* Mode of logging to test. Default is to run all supported modes */ +static enum log_mode_t host_log_mode_option = LOG_MODE_ALL; +/* Logging mode for current run */ +static enum log_mode_t host_log_mode; + +static bool clear_log_supported(void) +{ + return kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); +} + +static void clear_log_create_vm_done(struct kvm_vm *vm) +{ + struct kvm_enable_cap cap = {}; + u64 manual_caps; + + manual_caps = kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); + TEST_ASSERT(manual_caps, "MANUAL_CAPS is zero!"); + manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | + KVM_DIRTY_LOG_INITIALLY_SET); + cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; + cap.args[0] = manual_caps; + vm_enable_cap(vm, &cap); +} + +static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot, + void *bitmap, uint32_t num_pages) +{ + kvm_vm_get_dirty_log(vm, slot, bitmap); +} + +static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot, + void *bitmap, uint32_t num_pages) +{ + kvm_vm_get_dirty_log(vm, slot, bitmap); + kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages); +} + +struct log_mode { + const char *name; + /* Return true if this mode is supported, otherwise false */ + bool (*supported)(void); + /* Hook when the vm creation is done (before vcpu creation) */ + void (*create_vm_done)(struct kvm_vm *vm); + /* Hook to collect the dirty pages into the bitmap provided */ + void (*collect_dirty_pages) (struct kvm_vm *vm, int slot, + void *bitmap, uint32_t num_pages); +} log_modes[LOG_MODE_NUM] = { + { + .name = "dirty-log", + .collect_dirty_pages = dirty_log_collect_dirty_pages, + }, + { + .name = "clear-log", + .supported = clear_log_supported, + .create_vm_done = clear_log_create_vm_done, + .collect_dirty_pages = clear_log_collect_dirty_pages, + }, +}; + +/* + * We use this bitmap to track some pages that should have its dirty + * bit set in the _next_ iteration. For example, if we detected the + * page value changed to current iteration but at the same time the + * page bit is cleared in the latest bitmap, then the system must + * report that write in the next get dirty log call. + */ +static unsigned long *host_bmap_track; + +static void log_modes_dump(void) +{ + int i; + + printf("all"); + for (i = 0; i < LOG_MODE_NUM; i++) + printf(", %s", log_modes[i].name); + printf("\n"); +} + +static bool log_mode_supported(void) +{ + struct log_mode *mode = &log_modes[host_log_mode]; + + if (mode->supported) + return mode->supported(); + + return true; +} + +static void log_mode_create_vm_done(struct kvm_vm *vm) +{ + struct log_mode *mode = &log_modes[host_log_mode]; + + if (mode->create_vm_done) + mode->create_vm_done(vm); +} + +static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot, + void *bitmap, uint32_t num_pages) +{ + struct log_mode *mode = &log_modes[host_log_mode]; + + TEST_ASSERT(mode->collect_dirty_pages != NULL, + "collect_dirty_pages() is required for any log mode!"); + mode->collect_dirty_pages(vm, slot, bitmap, num_pages); +} + +static void generate_random_array(uint64_t *guest_array, uint64_t size) +{ + uint64_t i; + + for (i = 0; i < size; i++) + guest_array[i] = random(); +} + +static void *vcpu_worker(void *data) +{ + int ret; + struct kvm_vm *vm = data; + uint64_t *guest_array; + uint64_t pages_count = 0; + struct kvm_run *run; + + run = vcpu_state(vm, VCPU_ID); + + guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); + generate_random_array(guest_array, TEST_PAGES_PER_LOOP); + + while (!READ_ONCE(host_quit)) { + /* Let the guest dirty the random pages */ + ret = _vcpu_run(vm, VCPU_ID); + TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); + if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) { + pages_count += TEST_PAGES_PER_LOOP; + generate_random_array(guest_array, TEST_PAGES_PER_LOOP); + } else { + TEST_FAIL("Invalid guest sync status: " + "exit_reason=%s\n", + exit_reason_str(run->exit_reason)); + } + } + + pr_info("Dirtied %"PRIu64" pages\n", pages_count); + + return NULL; +} + +static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap) +{ + uint64_t step = vm_num_host_pages(mode, 1); + uint64_t page; + uint64_t *value_ptr; + + for (page = 0; page < host_num_pages; page += step) { + value_ptr = host_test_mem + page * host_page_size; + + /* If this is a special page that we were tracking... */ + if (test_and_clear_bit_le(page, host_bmap_track)) { + host_track_next_count++; + TEST_ASSERT(test_bit_le(page, bmap), + "Page %"PRIu64" should have its dirty bit " + "set in this iteration but it is missing", + page); + } + + if (test_and_clear_bit_le(page, bmap)) { + host_dirty_count++; + /* + * If the bit is set, the value written onto + * the corresponding page should be either the + * previous iteration number or the current one. + */ + TEST_ASSERT(*value_ptr == iteration || + *value_ptr == iteration - 1, + "Set page %"PRIu64" value %"PRIu64 + " incorrect (iteration=%"PRIu64")", + page, *value_ptr, iteration); + } else { + host_clear_count++; + /* + * If cleared, the value written can be any + * value smaller or equals to the iteration + * number. Note that the value can be exactly + * (iteration-1) if that write can happen + * like this: + * + * (1) increase loop count to "iteration-1" + * (2) write to page P happens (with value + * "iteration-1") + * (3) get dirty log for "iteration-1"; we'll + * see that page P bit is set (dirtied), + * and not set the bit in host_bmap_track + * (4) increase loop count to "iteration" + * (which is current iteration) + * (5) get dirty log for current iteration, + * we'll see that page P is cleared, with + * value "iteration-1". + */ + TEST_ASSERT(*value_ptr <= iteration, + "Clear page %"PRIu64" value %"PRIu64 + " incorrect (iteration=%"PRIu64")", + page, *value_ptr, iteration); + if (*value_ptr == iteration) { + /* + * This page is _just_ modified; it + * should report its dirtyness in the + * next run + */ + set_bit_le(page, host_bmap_track); + } + } + } +} + +static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, + uint64_t extra_mem_pages, void *guest_code) +{ + struct kvm_vm *vm; + uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; + + pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); + + vm = vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); + kvm_vm_elf_load(vm, program_invocation_name, 0, 0); +#ifdef __x86_64__ + vm_create_irqchip(vm); +#endif + log_mode_create_vm_done(vm); + vm_vcpu_add_default(vm, vcpuid, guest_code); + return vm; +} + +#define DIRTY_MEM_BITS 30 /* 1G */ +#define PAGE_SHIFT_4K 12 + +static void run_test(enum vm_guest_mode mode, unsigned long iterations, + unsigned long interval, uint64_t phys_offset) +{ + pthread_t vcpu_thread; + struct kvm_vm *vm; + unsigned long *bmap; + + if (!log_mode_supported()) { + print_skip("Log mode '%s' not supported", + log_modes[host_log_mode].name); + return; + } + + /* + * We reserve page table for 2 times of extra dirty mem which + * will definitely cover the original (1G+) test range. Here + * we do the calculation with 4K page size which is the + * smallest so the page number will be enough for all archs + * (e.g., 64K page size guest will need even less memory for + * page tables). + */ + vm = create_vm(mode, VCPU_ID, + 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), + guest_code); + + guest_page_size = vm_get_page_size(vm); + /* + * A little more than 1G of guest page sized pages. Cover the + * case where the size is not aligned to 64 pages. + */ + guest_num_pages = (1ul << (DIRTY_MEM_BITS - + vm_get_page_shift(vm))) + 3; + guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); + + host_page_size = getpagesize(); + host_num_pages = vm_num_host_pages(mode, guest_num_pages); + + if (!phys_offset) { + guest_test_phys_mem = (vm_get_max_gfn(vm) - + guest_num_pages) * guest_page_size; + guest_test_phys_mem &= ~(host_page_size - 1); + } else { + guest_test_phys_mem = phys_offset; + } + +#ifdef __s390x__ + /* Align to 1M (segment size) */ + guest_test_phys_mem &= ~((1 << 20) - 1); +#endif + + pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); + + bmap = bitmap_alloc(host_num_pages); + host_bmap_track = bitmap_alloc(host_num_pages); + + /* Add an extra memory slot for testing dirty logging */ + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + guest_test_phys_mem, + TEST_MEM_SLOT_INDEX, + guest_num_pages, + KVM_MEM_LOG_DIRTY_PAGES); + + /* Do mapping for the dirty track memory slot */ + virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0); + + /* Cache the HVA pointer of the region */ + host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); + +#ifdef __x86_64__ + vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); +#endif + ucall_init(vm, NULL); + + /* Export the shared variables to the guest */ + sync_global_to_guest(vm, host_page_size); + sync_global_to_guest(vm, guest_page_size); + sync_global_to_guest(vm, guest_test_virt_mem); + sync_global_to_guest(vm, guest_num_pages); + + /* Start the iterations */ + iteration = 1; + sync_global_to_guest(vm, iteration); + host_quit = false; + host_dirty_count = 0; + host_clear_count = 0; + host_track_next_count = 0; + + pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); + + while (iteration < iterations) { + /* Give the vcpu thread some time to dirty some pages */ + usleep(interval * 1000); + log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX, + bmap, host_num_pages); + vm_dirty_log_verify(mode, bmap); + iteration++; + sync_global_to_guest(vm, iteration); + } + + /* Tell the vcpu thread to quit */ + host_quit = true; + pthread_join(vcpu_thread, NULL); + + pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " + "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, + host_track_next_count); + + free(bmap); + free(host_bmap_track); + ucall_uninit(vm); + kvm_vm_free(vm); +} + +struct guest_mode { + bool supported; + bool enabled; +}; +static struct guest_mode guest_modes[NUM_VM_MODES]; + +#define guest_mode_init(mode, supported, enabled) ({ \ + guest_modes[mode] = (struct guest_mode){ supported, enabled }; \ +}) + +static void help(char *name) +{ + int i; + + puts(""); + printf("usage: %s [-h] [-i iterations] [-I interval] " + "[-p offset] [-m mode]\n", name); + puts(""); + printf(" -i: specify iteration counts (default: %"PRIu64")\n", + TEST_HOST_LOOP_N); + printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", + TEST_HOST_LOOP_INTERVAL); + printf(" -p: specify guest physical test memory offset\n" + " Warning: a low offset can conflict with the loaded test code.\n"); + printf(" -M: specify the host logging mode " + "(default: run all log modes). Supported modes: \n\t"); + log_modes_dump(); + printf(" -m: specify the guest mode ID to test " + "(default: test all supported modes)\n" + " This option may be used multiple times.\n" + " Guest mode IDs:\n"); + for (i = 0; i < NUM_VM_MODES; ++i) { + printf(" %d: %s%s\n", i, vm_guest_mode_string(i), + guest_modes[i].supported ? " (supported)" : ""); + } + puts(""); + exit(0); +} + +int main(int argc, char *argv[]) +{ + unsigned long iterations = TEST_HOST_LOOP_N; + unsigned long interval = TEST_HOST_LOOP_INTERVAL; + bool mode_selected = false; + uint64_t phys_offset = 0; + unsigned int mode; + int opt, i, j; + +#ifdef __x86_64__ + guest_mode_init(VM_MODE_PXXV48_4K, true, true); +#endif +#ifdef __aarch64__ + guest_mode_init(VM_MODE_P40V48_4K, true, true); + guest_mode_init(VM_MODE_P40V48_64K, true, true); + + { + unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); + + if (limit >= 52) + guest_mode_init(VM_MODE_P52V48_64K, true, true); + if (limit >= 48) { + guest_mode_init(VM_MODE_P48V48_4K, true, true); + guest_mode_init(VM_MODE_P48V48_64K, true, true); + } + } +#endif +#ifdef __s390x__ + guest_mode_init(VM_MODE_P40V48_4K, true, true); +#endif + + while ((opt = getopt(argc, argv, "hi:I:p:m:M:")) != -1) { + switch (opt) { + case 'i': + iterations = strtol(optarg, NULL, 10); + break; + case 'I': + interval = strtol(optarg, NULL, 10); + break; + case 'p': + phys_offset = strtoull(optarg, NULL, 0); + break; + case 'm': + if (!mode_selected) { + for (i = 0; i < NUM_VM_MODES; ++i) + guest_modes[i].enabled = false; + mode_selected = true; + } + mode = strtoul(optarg, NULL, 10); + TEST_ASSERT(mode < NUM_VM_MODES, + "Guest mode ID %d too big", mode); + guest_modes[mode].enabled = true; + break; + case 'M': + if (!strcmp(optarg, "all")) { + host_log_mode_option = LOG_MODE_ALL; + break; + } + for (i = 0; i < LOG_MODE_NUM; i++) { + if (!strcmp(optarg, log_modes[i].name)) { + pr_info("Setting log mode to: '%s'\n", + optarg); + host_log_mode_option = i; + break; + } + } + if (i == LOG_MODE_NUM) { + printf("Log mode '%s' invalid. Please choose " + "from: ", optarg); + log_modes_dump(); + exit(1); + } + break; + case 'h': + default: + help(argv[0]); + break; + } + } + + TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); + TEST_ASSERT(interval > 0, "Interval must be greater than zero"); + + pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", + iterations, interval); + + srandom(time(0)); + + for (i = 0; i < NUM_VM_MODES; ++i) { + if (!guest_modes[i].enabled) + continue; + TEST_ASSERT(guest_modes[i].supported, + "Guest mode ID %d (%s) not supported.", + i, vm_guest_mode_string(i)); + if (host_log_mode_option == LOG_MODE_ALL) { + /* Run each log mode */ + for (j = 0; j < LOG_MODE_NUM; j++) { + pr_info("Testing Log Mode '%s'\n", + log_modes[j].name); + host_log_mode = j; + run_test(i, iterations, interval, phys_offset); + } + } else { + host_log_mode = host_log_mode_option; + run_test(i, iterations, interval, phys_offset); + } + } + + return 0; +} |