diff options
Diffstat (limited to 'tools/testing/selftests/kvm/dirty_log_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/dirty_log_test.c | 69 |
1 files changed, 57 insertions, 12 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c index bb2752d78fe3..81edbd23d371 100644 --- a/tools/testing/selftests/kvm/dirty_log_test.c +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -17,6 +17,7 @@ #include <linux/bitmap.h> #include <linux/bitops.h> #include <asm/barrier.h> +#include <linux/atomic.h> #include "kvm_util.h" #include "test_util.h" @@ -137,12 +138,20 @@ 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; +static sem_t sem_vcpu_stop; +static sem_t sem_vcpu_cont; +/* + * This is only set by main thread, and only cleared by vcpu thread. It is + * used to request vcpu thread to stop at the next GUEST_SYNC, since GUEST_SYNC + * is the only place that we'll guarantee both "dirty bit" and "dirty data" + * will match. E.g., SIG_IPI won't guarantee that if the vcpu is interrupted + * after setting dirty bit but before the data is written. + */ +static atomic_t vcpu_sync_stop_requested; /* * This is updated by the vcpu thread to tell the host whether it's a * ring-full event. It should only be read until a sem_wait() of - * dirty_ring_vcpu_stop and before vcpu continues to run. + * sem_vcpu_stop and before vcpu continues to run. */ static bool dirty_ring_vcpu_ring_full; /* @@ -234,6 +243,17 @@ static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot, kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages); } +/* Should only be called after a GUEST_SYNC */ +static void vcpu_handle_sync_stop(void) +{ + if (atomic_read(&vcpu_sync_stop_requested)) { + /* It means main thread is sleeping waiting */ + atomic_set(&vcpu_sync_stop_requested, false); + sem_post(&sem_vcpu_stop); + sem_wait_until(&sem_vcpu_cont); + } +} + static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int err) { struct kvm_run *run = vcpu_state(vm, VCPU_ID); @@ -244,6 +264,8 @@ static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int 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)); + + vcpu_handle_sync_stop(); } static bool dirty_ring_supported(void) @@ -301,13 +323,13 @@ static void dirty_ring_wait_vcpu(void) { /* This makes sure that hardware PML cache flushed */ vcpu_kick(); - sem_wait_until(&dirty_ring_vcpu_stop); + sem_wait_until(&sem_vcpu_stop); } static void dirty_ring_continue_vcpu(void) { pr_info("Notifying vcpu to continue\n"); - sem_post(&dirty_ring_vcpu_cont); + sem_post(&sem_vcpu_cont); } static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot, @@ -361,11 +383,11 @@ static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err) /* Update the flag first before pause */ WRITE_ONCE(dirty_ring_vcpu_ring_full, run->exit_reason == KVM_EXIT_DIRTY_RING_FULL); - sem_post(&dirty_ring_vcpu_stop); + sem_post(&sem_vcpu_stop); pr_info("vcpu stops because %s...\n", dirty_ring_vcpu_ring_full ? "dirty ring is full" : "vcpu is kicked out"); - sem_wait_until(&dirty_ring_vcpu_cont); + sem_wait_until(&sem_vcpu_cont); pr_info("vcpu continues now.\n"); } else { TEST_ASSERT(false, "Invalid guest sync status: " @@ -377,7 +399,7 @@ static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err) 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); + sem_post(&sem_vcpu_cont); } struct log_mode { @@ -505,9 +527,8 @@ static void *vcpu_worker(void *data) */ sigmask->len = 8; pthread_sigmask(0, NULL, sigset); + sigdelset(sigset, SIG_IPI); vcpu_ioctl(vm, VCPU_ID, KVM_SET_SIGNAL_MASK, sigmask); - sigaddset(sigset, SIG_IPI); - pthread_sigmask(SIG_BLOCK, sigset, NULL); sigemptyset(sigset); sigaddset(sigset, SIG_IPI); @@ -768,7 +789,25 @@ static void run_test(enum vm_guest_mode mode, void *arg) usleep(p->interval * 1000); log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX, bmap, host_num_pages); + + /* + * See vcpu_sync_stop_requested definition for details on why + * we need to stop vcpu when verify data. + */ + atomic_set(&vcpu_sync_stop_requested, true); + sem_wait_until(&sem_vcpu_stop); + /* + * NOTE: for dirty ring, it's possible that we didn't stop at + * GUEST_SYNC but instead we stopped because ring is full; + * that's okay too because ring full means we're only missing + * the flush of the last page, and since we handle the last + * page specially verification will succeed anyway. + */ + assert(host_log_mode == LOG_MODE_DIRTY_RING || + atomic_read(&vcpu_sync_stop_requested) == false); vm_dirty_log_verify(mode, bmap); + sem_post(&sem_vcpu_cont); + iteration++; sync_global_to_guest(vm, iteration); } @@ -818,9 +857,10 @@ int main(int argc, char *argv[]) .interval = TEST_HOST_LOOP_INTERVAL, }; int opt, i; + sigset_t sigset; - sem_init(&dirty_ring_vcpu_stop, 0, 0); - sem_init(&dirty_ring_vcpu_cont, 0, 0); + sem_init(&sem_vcpu_stop, 0, 0); + sem_init(&sem_vcpu_cont, 0, 0); guest_modes_append_default(); @@ -876,6 +916,11 @@ int main(int argc, char *argv[]) srandom(time(0)); + /* Ensure that vCPU threads start with SIG_IPI blocked. */ + sigemptyset(&sigset); + sigaddset(&sigset, SIG_IPI); + pthread_sigmask(SIG_BLOCK, &sigset, NULL); + if (host_log_mode_option == LOG_MODE_ALL) { /* Run each log mode */ for (i = 0; i < LOG_MODE_NUM; i++) { |