diff options
| -rw-r--r-- | tools/testing/selftests/kvm/dirty_log_test.c | 254 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/kvm_util.h | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/lib/kvm_util.c | 72 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/lib/kvm_util_internal.h | 4 |
4 files changed, 320 insertions, 13 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c index 9215b26af10c..a7da4d9471e1 100644 --- a/tools/testing/selftests/kvm/dirty_log_test.c +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -12,8 +12,13 @@ #include <unistd.h> #include <time.h> #include <pthread.h> +#include <semaphore.h> +#include <sys/types.h> +#include <signal.h> +#include <errno.h> #include <linux/bitmap.h> #include <linux/bitops.h> +#include <asm/barrier.h> #include "test_util.h" #include "kvm_util.h" @@ -57,6 +62,8 @@ # define test_and_clear_bit_le test_and_clear_bit #endif +#define TEST_DIRTY_RING_COUNT 1024 + /* * Guest/Host shared variables. Ensure addr_gva2hva() and/or * sync_global_to/from_guest() are used when accessing from @@ -128,6 +135,25 @@ static uint64_t host_dirty_count; static uint64_t host_clear_count; static uint64_t host_track_next_count; +/* Whether dirty ring reset is requested, or finished */ +static sem_t dirty_ring_vcpu_stop; +static sem_t dirty_ring_vcpu_cont; +/* + * This is only used for verifying the dirty pages. Dirty ring has a very + * tricky case when the ring just got full, kvm will do userspace exit due to + * ring full. When that happens, the very last PFN is set but actually the + * data is not changed (the guest WRITE is not really applied yet), because + * we found that the dirty ring is full, refused to continue the vcpu, and + * recorded the dirty gfn with the old contents. + * + * For this specific case, it's safe to skip checking this pfn for this + * bit, because it's a redundant bit, and when the write happens later the bit + * will be set again. We use this variable to always keep track of the latest + * dirty gfn we've collected, so that if a mismatch of data found later in the + * verifying process, we let it pass. + */ +static uint64_t dirty_ring_last_page; + enum log_mode_t { /* Only use KVM_GET_DIRTY_LOG for logging */ LOG_MODE_DIRTY_LOG = 0, @@ -135,6 +161,9 @@ enum log_mode_t { /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */ LOG_MODE_CLEAR_LOG = 1, + /* Use dirty ring for logging */ + LOG_MODE_DIRTY_RING = 2, + LOG_MODE_NUM, /* Run all supported modes */ @@ -145,6 +174,20 @@ enum log_mode_t { 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 pthread_t vcpu_thread; + +/* + * In our test we do signal tricks, let's use a better version of + * sem_wait to avoid signal interrupts + */ +static void sem_wait_until(sem_t *sem) +{ + int ret; + + do + ret = sem_wait(sem); + while (ret == -1 && errno == EINTR); +} static bool clear_log_supported(void) { @@ -178,15 +221,131 @@ static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot, kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages); } -static void default_after_vcpu_run(struct kvm_vm *vm) +static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int err) { struct kvm_run *run = vcpu_state(vm, VCPU_ID); + TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR), + "vcpu run failed: errno=%d", err); + TEST_ASSERT(get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC, "Invalid guest sync status: exit_reason=%s\n", exit_reason_str(run->exit_reason)); } +static bool dirty_ring_supported(void) +{ + return kvm_check_cap(KVM_CAP_DIRTY_LOG_RING); +} + +static void dirty_ring_create_vm_done(struct kvm_vm *vm) +{ + /* + * Switch to dirty ring mode after VM creation but before any + * of the vcpu creation. + */ + vm_enable_dirty_ring(vm, TEST_DIRTY_RING_COUNT * + sizeof(struct kvm_dirty_gfn)); +} + +static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn) +{ + return gfn->flags == KVM_DIRTY_GFN_F_DIRTY; +} + +static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn) +{ + gfn->flags = KVM_DIRTY_GFN_F_RESET; +} + +static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns, + int slot, void *bitmap, + uint32_t num_pages, uint32_t *fetch_index) +{ + struct kvm_dirty_gfn *cur; + uint32_t count = 0; + + while (true) { + cur = &dirty_gfns[*fetch_index % TEST_DIRTY_RING_COUNT]; + if (!dirty_gfn_is_dirtied(cur)) + break; + TEST_ASSERT(cur->slot == slot, "Slot number didn't match: " + "%u != %u", cur->slot, slot); + TEST_ASSERT(cur->offset < num_pages, "Offset overflow: " + "0x%llx >= 0x%x", cur->offset, num_pages); + //pr_info("fetch 0x%x page %llu\n", *fetch_index, cur->offset); + set_bit_le(cur->offset, bitmap); + dirty_ring_last_page = cur->offset; + dirty_gfn_set_collected(cur); + (*fetch_index)++; + count++; + } + + return count; +} + +static void dirty_ring_wait_vcpu(void) +{ + sem_wait_until(&dirty_ring_vcpu_stop); +} + +static void dirty_ring_continue_vcpu(void) +{ + pr_info("Notifying vcpu to continue\n"); + sem_post(&dirty_ring_vcpu_cont); +} + +static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot, + void *bitmap, uint32_t num_pages) +{ + /* We only have one vcpu */ + static uint32_t fetch_index = 0; + uint32_t count = 0, cleared; + + dirty_ring_wait_vcpu(); + + /* Only have one vcpu */ + count = dirty_ring_collect_one(vcpu_map_dirty_ring(vm, VCPU_ID), + slot, bitmap, num_pages, &fetch_index); + + cleared = kvm_vm_reset_dirty_ring(vm); + + /* Cleared pages should be the same as collected */ + TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch " + "with collected (%u)", cleared, count); + + dirty_ring_continue_vcpu(); + + pr_info("Iteration %ld collected %u pages\n", iteration, count); +} + +static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err) +{ + struct kvm_run *run = vcpu_state(vm, VCPU_ID); + + /* A ucall-sync or ring-full event is allowed */ + if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) { + /* We should allow this to continue */ + ; + } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL) { + /* Update the flag first before pause */ + sem_post(&dirty_ring_vcpu_stop); + pr_info("vcpu stops because dirty ring is full...\n"); + sem_wait_until(&dirty_ring_vcpu_cont); + pr_info("vcpu continues now.\n"); + } else { + TEST_ASSERT(false, "Invalid guest sync status: " + "exit_reason=%s\n", + exit_reason_str(run->exit_reason)); + } +} + +static void dirty_ring_before_vcpu_join(void) +{ + /* Kick another round of vcpu just to make sure it will quit */ + sem_post(&dirty_ring_vcpu_cont); +} + struct log_mode { const char *name; /* Return true if this mode is supported, otherwise false */ @@ -197,7 +356,8 @@ struct log_mode { void (*collect_dirty_pages) (struct kvm_vm *vm, int slot, void *bitmap, uint32_t num_pages); /* Hook to call when after each vcpu run */ - void (*after_vcpu_run)(struct kvm_vm *vm); + void (*after_vcpu_run)(struct kvm_vm *vm, int ret, int err); + void (*before_vcpu_join) (void); } log_modes[LOG_MODE_NUM] = { { .name = "dirty-log", @@ -211,6 +371,14 @@ struct log_mode { .collect_dirty_pages = clear_log_collect_dirty_pages, .after_vcpu_run = default_after_vcpu_run, }, + { + .name = "dirty-ring", + .supported = dirty_ring_supported, + .create_vm_done = dirty_ring_create_vm_done, + .collect_dirty_pages = dirty_ring_collect_dirty_pages, + .before_vcpu_join = dirty_ring_before_vcpu_join, + .after_vcpu_run = dirty_ring_after_vcpu_run, + }, }; /* @@ -260,12 +428,20 @@ static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot, mode->collect_dirty_pages(vm, slot, bitmap, num_pages); } -static void log_mode_after_vcpu_run(struct kvm_vm *vm) +static void log_mode_after_vcpu_run(struct kvm_vm *vm, int ret, int err) { struct log_mode *mode = &log_modes[host_log_mode]; if (mode->after_vcpu_run) - mode->after_vcpu_run(vm); + mode->after_vcpu_run(vm, ret, err); +} + +static void log_mode_before_vcpu_join(void) +{ + struct log_mode *mode = &log_modes[host_log_mode]; + + if (mode->before_vcpu_join) + mode->before_vcpu_join(); } static void generate_random_array(uint64_t *guest_array, uint64_t size) @@ -278,20 +454,22 @@ static void generate_random_array(uint64_t *guest_array, uint64_t size) static void *vcpu_worker(void *data) { - int ret; + int ret, vcpu_fd; struct kvm_vm *vm = data; uint64_t *guest_array; uint64_t pages_count = 0; + vcpu_fd = vcpu_get_fd(vm, VCPU_ID); + guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); while (!READ_ONCE(host_quit)) { + /* Clear any existing kick signals */ generate_random_array(guest_array, TEST_PAGES_PER_LOOP); pages_count += TEST_PAGES_PER_LOOP; /* Let the guest dirty the random pages */ - ret = _vcpu_run(vm, VCPU_ID); - TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); - log_mode_after_vcpu_run(vm); + ret = ioctl(vcpu_fd, KVM_RUN, NULL); + log_mode_after_vcpu_run(vm, ret, errno); } pr_info("Dirtied %"PRIu64" pages\n", pages_count); @@ -304,6 +482,7 @@ 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; + uint64_t min_iter = 0; for (page = 0; page < host_num_pages; page += step) { value_ptr = host_test_mem + page * host_page_size; @@ -318,14 +497,64 @@ static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap) } if (test_and_clear_bit_le(page, bmap)) { + bool matched; + 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, + matched = (*value_ptr == iteration || + *value_ptr == iteration - 1); + + if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) { + if (*value_ptr == iteration - 2 && min_iter <= iteration - 2) { + /* + * Short answer: this case is special + * only for dirty ring test where the + * page is the last page before a kvm + * dirty ring full in iteration N-2. + * + * Long answer: Assuming ring size R, + * one possible condition is: + * + * main thr vcpu thr + * -------- -------- + * iter=1 + * write 1 to page 0~(R-1) + * full, vmexit + * collect 0~(R-1) + * kick vcpu + * write 1 to (R-1)~(2R-2) + * full, vmexit + * iter=2 + * collect (R-1)~(2R-2) + * kick vcpu + * write 1 to (2R-2) + * (NOTE!!! "1" cached in cpu reg) + * write 2 to (2R-1)~(3R-3) + * full, vmexit + * iter=3 + * collect (2R-2)~(3R-3) + * (here if we read value on page + * "2R-2" is 1, while iter=3!!!) + * + * This however can only happen once per iteration. + */ + min_iter = iteration - 1; + continue; + } else if (page == dirty_ring_last_page) { + /* + * Please refer to comments in + * dirty_ring_last_page. + */ + continue; + } + } + + TEST_ASSERT(matched, "Set page %"PRIu64" value %"PRIu64 " incorrect (iteration=%"PRIu64")", page, *value_ptr, iteration); @@ -390,7 +619,6 @@ static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 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; @@ -488,6 +716,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations, /* Tell the vcpu thread to quit */ host_quit = true; + log_mode_before_vcpu_join(); pthread_join(vcpu_thread, NULL); pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " @@ -548,6 +777,9 @@ int main(int argc, char *argv[]) unsigned int mode; int opt, i, j; + sem_init(&dirty_ring_vcpu_stop, 0, 0); + sem_init(&dirty_ring_vcpu_cont, 0, 0); + #ifdef __x86_64__ guest_mode_init(VM_MODE_PXXV48_4K, true, true); #endif diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index b2c1364c0402..710009cc17fd 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -74,6 +74,7 @@ void kvm_vm_release(struct kvm_vm *vmp); void kvm_vm_get_dirty_log(struct kvm_vm *vm, int slot, void *log); void kvm_vm_clear_dirty_log(struct kvm_vm *vm, int slot, void *log, uint64_t first_page, uint32_t num_pages); +uint32_t kvm_vm_reset_dirty_ring(struct kvm_vm *vm); int kvm_memcmp_hva_gva(void *hva, struct kvm_vm *vm, const vm_vaddr_t gva, size_t len); @@ -148,6 +149,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva); struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid); void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid); int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid); +int vcpu_get_fd(struct kvm_vm *vm, uint32_t vcpuid); void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid); void vcpu_set_guest_debug(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_guest_debug *debug); @@ -201,6 +203,7 @@ void vcpu_nested_state_get(struct kvm_vm *vm, uint32_t vcpuid, int vcpu_nested_state_set(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_nested_state *state, bool ignore_error); #endif +void *vcpu_map_dirty_ring(struct kvm_vm *vm, uint32_t vcpuid); const char *exit_reason_str(unsigned int exit_reason); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index ef2114e1b7ad..a04302666b02 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -114,6 +114,16 @@ int vcpu_enable_cap(struct kvm_vm *vm, uint32_t vcpu_id, return r; } +void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size) +{ + struct kvm_enable_cap cap = { 0 }; + + cap.cap = KVM_CAP_DIRTY_LOG_RING; + cap.args[0] = ring_size; + vm_enable_cap(vm, &cap); + vm->dirty_ring_size = ring_size; +} + static void vm_open(struct kvm_vm *vm, int perm) { vm->kvm_fd = open(KVM_DEV_PATH, perm); @@ -328,6 +338,11 @@ void kvm_vm_clear_dirty_log(struct kvm_vm *vm, int slot, void *log, __func__, strerror(-ret)); } +uint32_t kvm_vm_reset_dirty_ring(struct kvm_vm *vm) +{ + return ioctl(vm->fd, KVM_RESET_DIRTY_RINGS); +} + /* * Userspace Memory Region Find * @@ -432,10 +447,17 @@ struct vcpu *vcpu_find(struct kvm_vm *vm, uint32_t vcpuid) * * Removes a vCPU from a VM and frees its resources. */ -static void vm_vcpu_rm(struct vcpu *vcpu) +static void vm_vcpu_rm(struct kvm_vm *vm, struct vcpu *vcpu) { int ret; + if (vcpu->dirty_gfns) { + ret = munmap(vcpu->dirty_gfns, vm->dirty_ring_size); + TEST_ASSERT(ret == 0, "munmap of VCPU dirty ring failed, " + "rc: %i errno: %i", ret, errno); + vcpu->dirty_gfns = NULL; + } + ret = munmap(vcpu->state, sizeof(*vcpu->state)); TEST_ASSERT(ret == 0, "munmap of VCPU fd failed, rc: %i " "errno: %i", ret, errno); @@ -453,7 +475,7 @@ void kvm_vm_release(struct kvm_vm *vmp) int ret; list_for_each_entry_safe(vcpu, tmp, &vmp->vcpus, list) - vm_vcpu_rm(vcpu); + vm_vcpu_rm(vmp, vcpu); ret = close(vmp->fd); TEST_ASSERT(ret == 0, "Close of vm fd failed,\n" @@ -1233,6 +1255,15 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid) return rc; } +int vcpu_get_fd(struct kvm_vm *vm, uint32_t vcpuid) +{ + struct vcpu *vcpu = vcpu_find(vm, vcpuid); + + TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid); + + return vcpu->fd; +} + void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid) { struct vcpu *vcpu = vcpu_find(vm, vcpuid); @@ -1561,6 +1592,42 @@ int _vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, return ret; } +void *vcpu_map_dirty_ring(struct kvm_vm *vm, uint32_t vcpuid) +{ + struct vcpu *vcpu; + uint32_t size = vm->dirty_ring_size; + + TEST_ASSERT(size > 0, "Should enable dirty ring first"); + + vcpu = vcpu_find(vm, vcpuid); + + TEST_ASSERT(vcpu, "Cannot find vcpu %u", vcpuid); + + if (!vcpu->dirty_gfns) { + void *addr; + + addr = mmap(NULL, size, PROT_READ, + MAP_PRIVATE, vcpu->fd, + vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET); + TEST_ASSERT(addr == MAP_FAILED, "Dirty ring mapped private"); + + addr = mmap(NULL, size, PROT_READ | PROT_EXEC, + MAP_PRIVATE, vcpu->fd, + vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET); + TEST_ASSERT(addr == MAP_FAILED, "Dirty ring mapped exec"); + + addr = mmap(NULL, size, PROT_READ | PROT_WRITE, + MAP_SHARED, vcpu->fd, + vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET); + TEST_ASSERT(addr != MAP_FAILED, "Dirty ring map failed"); + + vcpu->dirty_gfns = addr; + vcpu->dirty_gfns_count = size / sizeof(struct kvm_dirty_gfn); + } + + return vcpu->dirty_gfns; +} + /* * VM Ioctl * @@ -1680,6 +1747,7 @@ static struct exit_reason { {KVM_EXIT_INTERNAL_ERROR, "INTERNAL_ERROR"}, {KVM_EXIT_OSI, "OSI"}, {KVM_EXIT_PAPR_HCALL, "PAPR_HCALL"}, + {KVM_EXIT_DIRTY_RING_FULL, "DIRTY_RING_FULL"}, #ifdef KVM_EXIT_MEMORY_NOT_PRESENT {KVM_EXIT_MEMORY_NOT_PRESENT, "MEMORY_NOT_PRESENT"}, #endif diff --git a/tools/testing/selftests/kvm/lib/kvm_util_internal.h b/tools/testing/selftests/kvm/lib/kvm_util_internal.h index f07d383d03a1..34465dc562d8 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util_internal.h +++ b/tools/testing/selftests/kvm/lib/kvm_util_internal.h @@ -28,6 +28,9 @@ struct vcpu { uint32_t id; int fd; struct kvm_run *state; + struct kvm_dirty_gfn *dirty_gfns; + uint32_t fetch_index; + uint32_t dirty_gfns_count; }; struct kvm_vm { @@ -52,6 +55,7 @@ struct kvm_vm { vm_vaddr_t tss; vm_vaddr_t idt; vm_vaddr_t handlers; + uint32_t dirty_ring_size; }; struct vcpu *vcpu_find(struct kvm_vm *vm, uint32_t vcpuid); |