diff options
Diffstat (limited to 'migration/postcopy-ram.c')
| -rw-r--r-- | migration/postcopy-ram.c | 186 |
1 files changed, 183 insertions, 3 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a66dd536d9..b9a37ef255 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -33,6 +33,10 @@ #include "trace.h" #include "hw/boards.h" #include "exec/ramblock.h" +#include "socket.h" +#include "qemu-file.h" +#include "yank_functions.h" +#include "tls.h" /* Arbitrary limit on size of each discard command, * keeps them around ~200 bytes @@ -567,6 +571,11 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) { trace_postcopy_ram_incoming_cleanup_entry(); + if (mis->postcopy_prio_thread_created) { + qemu_thread_join(&mis->postcopy_prio_thread); + mis->postcopy_prio_thread_created = false; + } + if (mis->have_fault_thread) { Error *local_err = NULL; @@ -1102,8 +1111,13 @@ static int postcopy_temp_pages_setup(MigrationIncomingState *mis) int err, i, channels; void *temp_page; - /* TODO: will be boosted when enable postcopy preemption */ - mis->postcopy_channels = 1; + if (migrate_postcopy_preempt()) { + /* If preemption enabled, need extra channel for urgent requests */ + mis->postcopy_channels = RAM_CHANNEL_MAX; + } else { + /* Both precopy/postcopy on the same channel */ + mis->postcopy_channels = 1; + } channels = mis->postcopy_channels; mis->postcopy_tmp_pages = g_malloc0_n(sizeof(PostcopyTmpPage), channels); @@ -1170,7 +1184,7 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) return -1; } - postcopy_thread_create(mis, &mis->fault_thread, "postcopy/fault", + postcopy_thread_create(mis, &mis->fault_thread, "fault-default", postcopy_ram_fault_thread, QEMU_THREAD_JOINABLE); mis->have_fault_thread = true; @@ -1185,6 +1199,16 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) return -1; } + if (migrate_postcopy_preempt()) { + /* + * This thread needs to be created after the temp pages because + * it'll fetch RAM_CHANNEL_POSTCOPY PostcopyTmpPage immediately. + */ + postcopy_thread_create(mis, &mis->postcopy_prio_thread, "fault-fast", + postcopy_preempt_thread, QEMU_THREAD_JOINABLE); + mis->postcopy_prio_thread_created = true; + } + trace_postcopy_ram_enable_notify(); return 0; @@ -1514,3 +1538,159 @@ void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd) } } } + +bool postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file) +{ + /* + * The new loading channel has its own threads, so it needs to be + * blocked too. It's by default true, just be explicit. + */ + qemu_file_set_blocking(file, true); + mis->postcopy_qemufile_dst = file; + trace_postcopy_preempt_new_channel(); + + /* Start the migration immediately */ + return true; +} + +/* + * Setup the postcopy preempt channel with the IOC. If ERROR is specified, + * setup the error instead. This helper will free the ERROR if specified. + */ +static void +postcopy_preempt_send_channel_done(MigrationState *s, + QIOChannel *ioc, Error *local_err) +{ + if (local_err) { + migrate_set_error(s, local_err); + error_free(local_err); + } else { + migration_ioc_register_yank(ioc); + s->postcopy_qemufile_src = qemu_file_new_output(ioc); + trace_postcopy_preempt_new_channel(); + } + + /* + * Kick the waiter in all cases. The waiter should check upon + * postcopy_qemufile_src to know whether it failed or not. + */ + qemu_sem_post(&s->postcopy_qemufile_src_sem); +} + +static void +postcopy_preempt_tls_handshake(QIOTask *task, gpointer opaque) +{ + g_autoptr(QIOChannel) ioc = QIO_CHANNEL(qio_task_get_source(task)); + MigrationState *s = opaque; + Error *local_err = NULL; + + qio_task_propagate_error(task, &local_err); + postcopy_preempt_send_channel_done(s, ioc, local_err); +} + +static void +postcopy_preempt_send_channel_new(QIOTask *task, gpointer opaque) +{ + g_autoptr(QIOChannel) ioc = QIO_CHANNEL(qio_task_get_source(task)); + MigrationState *s = opaque; + QIOChannelTLS *tioc; + Error *local_err = NULL; + + if (qio_task_propagate_error(task, &local_err)) { + goto out; + } + + if (migrate_channel_requires_tls_upgrade(ioc)) { + tioc = migration_tls_client_create(s, ioc, s->hostname, &local_err); + if (!tioc) { + goto out; + } + trace_postcopy_preempt_tls_handshake(); + qio_channel_set_name(QIO_CHANNEL(tioc), "migration-tls-preempt"); + qio_channel_tls_handshake(tioc, postcopy_preempt_tls_handshake, + s, NULL, NULL); + /* Setup the channel until TLS handshake finished */ + return; + } + +out: + /* This handles both good and error cases */ + postcopy_preempt_send_channel_done(s, ioc, local_err); +} + +/* Returns 0 if channel established, -1 for error. */ +int postcopy_preempt_wait_channel(MigrationState *s) +{ + /* If preempt not enabled, no need to wait */ + if (!migrate_postcopy_preempt()) { + return 0; + } + + /* + * We need the postcopy preempt channel to be established before + * starting doing anything. + */ + qemu_sem_wait(&s->postcopy_qemufile_src_sem); + + return s->postcopy_qemufile_src ? 0 : -1; +} + +int postcopy_preempt_setup(MigrationState *s, Error **errp) +{ + if (!migrate_postcopy_preempt()) { + return 0; + } + + if (!migrate_multi_channels_is_allowed()) { + error_setg(errp, "Postcopy preempt is not supported as current " + "migration stream does not support multi-channels."); + return -1; + } + + /* Kick an async task to connect */ + socket_send_channel_create(postcopy_preempt_send_channel_new, s); + + return 0; +} + +static void postcopy_pause_ram_fast_load(MigrationIncomingState *mis) +{ + trace_postcopy_pause_fast_load(); + qemu_mutex_unlock(&mis->postcopy_prio_thread_mutex); + qemu_sem_wait(&mis->postcopy_pause_sem_fast_load); + qemu_mutex_lock(&mis->postcopy_prio_thread_mutex); + trace_postcopy_pause_fast_load_continued(); +} + +void *postcopy_preempt_thread(void *opaque) +{ + MigrationIncomingState *mis = opaque; + int ret; + + trace_postcopy_preempt_thread_entry(); + + rcu_register_thread(); + + qemu_sem_post(&mis->thread_sync_sem); + + /* Sending RAM_SAVE_FLAG_EOS to terminate this thread */ + qemu_mutex_lock(&mis->postcopy_prio_thread_mutex); + while (1) { + ret = ram_load_postcopy(mis->postcopy_qemufile_dst, + RAM_CHANNEL_POSTCOPY); + /* If error happened, go into recovery routine */ + if (ret) { + postcopy_pause_ram_fast_load(mis); + } else { + /* We're done */ + break; + } + } + qemu_mutex_unlock(&mis->postcopy_prio_thread_mutex); + + rcu_unregister_thread(); + + trace_postcopy_preempt_thread_exit(); + + return NULL; +} |