diff options
Diffstat (limited to 'migration.c')
| -rw-r--r-- | migration.c | 402 |
1 files changed, 297 insertions, 105 deletions
diff --git a/migration.c b/migration.c index 73ce170ddf..c69e864fcd 100644 --- a/migration.c +++ b/migration.c @@ -14,13 +14,14 @@ */ #include "qemu-common.h" -#include "migration.h" -#include "monitor.h" -#include "buffered_file.h" -#include "sysemu.h" -#include "block.h" -#include "qemu_socket.h" -#include "block-migration.h" +#include "migration/migration.h" +#include "monitor/monitor.h" +#include "migration/qemu-file.h" +#include "sysemu/sysemu.h" +#include "block/block.h" +#include "qemu/sockets.h" +#include "migration/block.h" +#include "qemu/thread.h" #include "qmp-commands.h" //#define DEBUG_MIGRATION @@ -43,6 +44,11 @@ enum { #define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ +/* Amount of time to allocate to each "chunk" of bandwidth-throttled + * data. */ +#define BUFFER_DELAY 100 +#define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) + /* Migration XBZRLE default cache size */ #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) @@ -272,7 +278,7 @@ static int migrate_fd_cleanup(MigrationState *s) s->file = NULL; } - migrate_fd_close(s); + assert(s->fd == -1); return ret; } @@ -296,18 +302,6 @@ static void migrate_fd_completed(MigrationState *s) notifier_list_notify(&migration_state_notifiers, s); } -static void migrate_fd_put_notify(void *opaque) -{ - MigrationState *s = opaque; - int ret; - - qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); - ret = qemu_file_put_notify(s->file); - if (ret) { - migrate_fd_error(s); - } -} - ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data, size_t size) { @@ -324,51 +318,9 @@ ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data, if (ret == -1) ret = -(s->get_error(s)); - if (ret == -EAGAIN) { - qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s); - } - return ret; } -void migrate_fd_put_ready(MigrationState *s) -{ - int ret; - - if (s->state != MIG_STATE_ACTIVE) { - DPRINTF("put_ready returning because of non-active state\n"); - return; - } - - DPRINTF("iterate\n"); - ret = qemu_savevm_state_iterate(s->file); - if (ret < 0) { - migrate_fd_error(s); - } else if (ret == 1) { - int old_vm_running = runstate_is_running(); - int64_t start_time, end_time; - - DPRINTF("done iterating\n"); - start_time = qemu_get_clock_ms(rt_clock); - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); - vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); - - if (qemu_savevm_state_complete(s->file) < 0) { - migrate_fd_error(s); - } else { - migrate_fd_completed(s); - } - end_time = qemu_get_clock_ms(rt_clock); - s->total_time = end_time - s->total_time; - s->downtime = end_time - start_time; - if (s->state != MIG_STATE_COMPLETED) { - if (old_vm_running) { - vm_start(); - } - } - } -} - static void migrate_fd_cancel(MigrationState *s) { if (s->state != MIG_STATE_ACTIVE) @@ -383,34 +335,10 @@ static void migrate_fd_cancel(MigrationState *s) migrate_fd_cleanup(s); } -int migrate_fd_wait_for_unfreeze(MigrationState *s) -{ - int ret; - - DPRINTF("wait for unfreeze\n"); - if (s->state != MIG_STATE_ACTIVE) - return -EINVAL; - - do { - fd_set wfds; - - FD_ZERO(&wfds); - FD_SET(s->fd, &wfds); - - ret = select(s->fd + 1, NULL, &wfds, NULL, NULL); - } while (ret == -1 && (s->get_error(s)) == EINTR); - - if (ret == -1) { - return -s->get_error(s); - } - return 0; -} - int migrate_fd_close(MigrationState *s) { int rc = 0; if (s->fd != -1) { - qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); rc = s->close(s); s->fd = -1; } @@ -443,23 +371,6 @@ bool migration_has_failed(MigrationState *s) s->state == MIG_STATE_ERROR); } -void migrate_fd_connect(MigrationState *s) -{ - int ret; - - s->state = MIG_STATE_ACTIVE; - s->file = qemu_fopen_ops_buffered(s); - - DPRINTF("beginning savevm\n"); - ret = qemu_savevm_state_begin(s->file, &s->params); - if (ret < 0) { - DPRINTF("failed, %d\n", ret); - migrate_fd_error(s); - return; - } - migrate_fd_put_ready(s); -} - static MigrationState *migrate_init(const MigrationParams *params) { MigrationState *s = migrate_get_current(); @@ -544,8 +455,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, error_propagate(errp, local_err); return; } - - notifier_list_notify(&migration_state_notifiers, s); } void qmp_migrate_cancel(Error **errp) @@ -609,3 +518,286 @@ int64_t migrate_xbzrle_cache_size(void) return s->xbzrle_cache_size; } + +/* migration thread support */ + + +static ssize_t buffered_flush(MigrationState *s) +{ + size_t offset = 0; + ssize_t ret = 0; + + DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size); + + while (s->bytes_xfer < s->xfer_limit && offset < s->buffer_size) { + size_t to_send = MIN(s->buffer_size - offset, s->xfer_limit - s->bytes_xfer); + ret = migrate_fd_put_buffer(s, s->buffer + offset, to_send); + if (ret <= 0) { + DPRINTF("error flushing data, %zd\n", ret); + break; + } else { + DPRINTF("flushed %zd byte(s)\n", ret); + offset += ret; + s->bytes_xfer += ret; + } + } + + DPRINTF("flushed %zu of %zu byte(s)\n", offset, s->buffer_size); + memmove(s->buffer, s->buffer + offset, s->buffer_size - offset); + s->buffer_size -= offset; + + if (ret < 0) { + return ret; + } + return offset; +} + +static int buffered_put_buffer(void *opaque, const uint8_t *buf, + int64_t pos, int size) +{ + MigrationState *s = opaque; + ssize_t error; + + DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos); + + error = qemu_file_get_error(s->file); + if (error) { + DPRINTF("flush when error, bailing: %s\n", strerror(-error)); + return error; + } + + if (size <= 0) { + return size; + } + + if (size > (s->buffer_capacity - s->buffer_size)) { + DPRINTF("increasing buffer capacity from %zu by %zu\n", + s->buffer_capacity, size + 1024); + + s->buffer_capacity += size + 1024; + + s->buffer = g_realloc(s->buffer, s->buffer_capacity); + } + + memcpy(s->buffer + s->buffer_size, buf, size); + s->buffer_size += size; + + return size; +} + +static int buffered_close(void *opaque) +{ + MigrationState *s = opaque; + ssize_t ret = 0; + int ret2; + + DPRINTF("closing\n"); + + s->xfer_limit = INT_MAX; + while (!qemu_file_get_error(s->file) && s->buffer_size) { + ret = buffered_flush(s); + if (ret < 0) { + break; + } + } + + ret2 = migrate_fd_close(s); + if (ret >= 0) { + ret = ret2; + } + ret = migrate_fd_close(s); + s->complete = true; + return ret; +} + +static int buffered_get_fd(void *opaque) +{ + MigrationState *s = opaque; + + return s->fd; +} + +/* + * The meaning of the return values is: + * 0: We can continue sending + * 1: Time to stop + * negative: There has been an error + */ +static int buffered_rate_limit(void *opaque) +{ + MigrationState *s = opaque; + int ret; + + ret = qemu_file_get_error(s->file); + if (ret) { + return ret; + } + + if (s->bytes_xfer > s->xfer_limit) { + return 1; + } + + return 0; +} + +static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate) +{ + MigrationState *s = opaque; + if (qemu_file_get_error(s->file)) { + goto out; + } + if (new_rate > SIZE_MAX) { + new_rate = SIZE_MAX; + } + + s->xfer_limit = new_rate / 10; + +out: + return s->xfer_limit; +} + +static int64_t buffered_get_rate_limit(void *opaque) +{ + MigrationState *s = opaque; + + return s->xfer_limit; +} + +static bool migrate_fd_put_ready(MigrationState *s, uint64_t max_size) +{ + int ret; + uint64_t pending_size; + bool last_round = false; + + qemu_mutex_lock_iothread(); + if (s->state != MIG_STATE_ACTIVE) { + DPRINTF("put_ready returning because of non-active state\n"); + qemu_mutex_unlock_iothread(); + return false; + } + if (s->first_time) { + s->first_time = false; + DPRINTF("beginning savevm\n"); + ret = qemu_savevm_state_begin(s->file, &s->params); + if (ret < 0) { + DPRINTF("failed, %d\n", ret); + migrate_fd_error(s); + qemu_mutex_unlock_iothread(); + return false; + } + } + + DPRINTF("iterate\n"); + pending_size = qemu_savevm_state_pending(s->file, max_size); + DPRINTF("pending size %lu max %lu\n", pending_size, max_size); + if (pending_size >= max_size) { + ret = qemu_savevm_state_iterate(s->file); + if (ret < 0) { + migrate_fd_error(s); + } + } else { + int old_vm_running = runstate_is_running(); + int64_t start_time, end_time; + + DPRINTF("done iterating\n"); + start_time = qemu_get_clock_ms(rt_clock); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + if (old_vm_running) { + vm_stop(RUN_STATE_FINISH_MIGRATE); + } else { + vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); + } + + if (qemu_savevm_state_complete(s->file) < 0) { + migrate_fd_error(s); + } else { + migrate_fd_completed(s); + } + end_time = qemu_get_clock_ms(rt_clock); + s->total_time = end_time - s->total_time; + s->downtime = end_time - start_time; + if (s->state != MIG_STATE_COMPLETED) { + if (old_vm_running) { + vm_start(); + } + } + last_round = true; + } + qemu_mutex_unlock_iothread(); + + return last_round; +} + +static void *buffered_file_thread(void *opaque) +{ + MigrationState *s = opaque; + int64_t initial_time = qemu_get_clock_ms(rt_clock); + int64_t max_size = 0; + bool last_round = false; + + while (true) { + int64_t current_time = qemu_get_clock_ms(rt_clock); + + if (s->complete) { + break; + } + if (current_time >= initial_time + BUFFER_DELAY) { + uint64_t transferred_bytes = s->bytes_xfer; + uint64_t time_spent = current_time - initial_time; + double bandwidth = transferred_bytes / time_spent; + max_size = bandwidth * migrate_max_downtime() / 1000000; + + DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64 + " bandwidth %g max_size %" PRId64 "\n", + transferred_bytes, time_spent, bandwidth, max_size); + + s->bytes_xfer = 0; + initial_time = current_time; + } + if (!last_round && (s->bytes_xfer >= s->xfer_limit)) { + /* usleep expects microseconds */ + g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); + } + if (buffered_flush(s) < 0) { + break; + } + + DPRINTF("file is ready\n"); + if (s->bytes_xfer < s->xfer_limit) { + DPRINTF("notifying client\n"); + last_round = migrate_fd_put_ready(s, max_size); + } + } + + g_free(s->buffer); + return NULL; +} + +static const QEMUFileOps buffered_file_ops = { + .get_fd = buffered_get_fd, + .put_buffer = buffered_put_buffer, + .close = buffered_close, + .rate_limit = buffered_rate_limit, + .get_rate_limit = buffered_get_rate_limit, + .set_rate_limit = buffered_set_rate_limit, +}; + +void migrate_fd_connect(MigrationState *s) +{ + s->state = MIG_STATE_ACTIVE; + s->bytes_xfer = 0; + s->buffer = NULL; + s->buffer_size = 0; + s->buffer_capacity = 0; + + s->first_time = true; + + s->xfer_limit = s->bandwidth_limit / XFER_LIMIT_RATIO; + s->complete = false; + + s->file = qemu_fopen_ops(s, &buffered_file_ops); + + qemu_thread_create(&s->thread, buffered_file_thread, s, + QEMU_THREAD_DETACHED); + notifier_list_notify(&migration_state_notifiers, s); +} |