34dfc5e407
Socket transport backend for 'migrate'/'migrate-incoming' QAPIs accept new wire protocol of MigrateAddress struct. It is achived by parsing 'uri' string and storing migration parameters required for socket connection into well defined SocketAddress struct. Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com> Signed-off-by: Het Gala <het.gala@nutanix.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231023182053.8711-6-farosas@suse.de>
3681 lines
110 KiB
C
3681 lines
110 KiB
C
/*
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* QEMU live migration
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*
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* Copyright IBM, Corp. 2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu/osdep.h"
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#include "qemu/cutils.h"
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#include "qemu/error-report.h"
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#include "qemu/main-loop.h"
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#include "migration/blocker.h"
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#include "exec.h"
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#include "fd.h"
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#include "file.h"
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#include "socket.h"
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#include "sysemu/runstate.h"
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#include "sysemu/sysemu.h"
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#include "sysemu/cpu-throttle.h"
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#include "rdma.h"
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#include "ram.h"
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#include "ram-compress.h"
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#include "migration/global_state.h"
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#include "migration/misc.h"
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#include "migration.h"
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#include "migration-stats.h"
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#include "savevm.h"
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#include "qemu-file.h"
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#include "channel.h"
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#include "migration/vmstate.h"
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#include "block/block.h"
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#include "qapi/error.h"
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#include "qapi/clone-visitor.h"
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#include "qapi/qapi-visit-migration.h"
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#include "qapi/qapi-visit-sockets.h"
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#include "qapi/qapi-commands-migration.h"
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#include "qapi/qapi-events-migration.h"
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#include "qapi/qmp/qerror.h"
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#include "qapi/qmp/qnull.h"
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#include "qemu/rcu.h"
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#include "block.h"
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#include "postcopy-ram.h"
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#include "qemu/thread.h"
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#include "trace.h"
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#include "exec/target_page.h"
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#include "io/channel-buffer.h"
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#include "io/channel-tls.h"
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#include "migration/colo.h"
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#include "hw/boards.h"
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#include "monitor/monitor.h"
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#include "net/announce.h"
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#include "qemu/queue.h"
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#include "multifd.h"
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#include "threadinfo.h"
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#include "qemu/yank.h"
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#include "sysemu/cpus.h"
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#include "yank_functions.h"
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#include "sysemu/qtest.h"
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#include "options.h"
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#include "sysemu/dirtylimit.h"
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#include "qemu/sockets.h"
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static NotifierList migration_state_notifiers =
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NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
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/* Messages sent on the return path from destination to source */
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enum mig_rp_message_type {
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MIG_RP_MSG_INVALID = 0, /* Must be 0 */
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MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
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MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
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MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
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MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
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MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */
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MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */
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MIG_RP_MSG_SWITCHOVER_ACK, /* Tell source it's OK to do switchover */
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MIG_RP_MSG_MAX
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};
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/* When we add fault tolerance, we could have several
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migrations at once. For now we don't need to add
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dynamic creation of migration */
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static MigrationState *current_migration;
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static MigrationIncomingState *current_incoming;
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static GSList *migration_blockers[MIG_MODE__MAX];
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static bool migration_object_check(MigrationState *ms, Error **errp);
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static int migration_maybe_pause(MigrationState *s,
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int *current_active_state,
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int new_state);
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static void migrate_fd_cancel(MigrationState *s);
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static bool close_return_path_on_source(MigrationState *s);
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static void migration_downtime_start(MigrationState *s)
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{
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trace_vmstate_downtime_checkpoint("src-downtime-start");
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s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
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}
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static void migration_downtime_end(MigrationState *s)
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{
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int64_t now = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
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/*
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* If downtime already set, should mean that postcopy already set it,
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* then that should be the real downtime already.
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*/
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if (!s->downtime) {
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s->downtime = now - s->downtime_start;
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}
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trace_vmstate_downtime_checkpoint("src-downtime-end");
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}
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static bool migration_needs_multiple_sockets(void)
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{
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return migrate_multifd() || migrate_postcopy_preempt();
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}
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static bool uri_supports_multi_channels(const char *uri)
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{
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return strstart(uri, "tcp:", NULL) || strstart(uri, "unix:", NULL) ||
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strstart(uri, "vsock:", NULL);
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}
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static bool
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migration_channels_and_uri_compatible(const char *uri, Error **errp)
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{
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if (migration_needs_multiple_sockets() &&
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!uri_supports_multi_channels(uri)) {
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error_setg(errp, "Migration requires multi-channel URIs (e.g. tcp)");
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return false;
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}
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return true;
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}
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static gint page_request_addr_cmp(gconstpointer ap, gconstpointer bp)
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{
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uintptr_t a = (uintptr_t) ap, b = (uintptr_t) bp;
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return (a > b) - (a < b);
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}
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int migration_stop_vm(RunState state)
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{
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int ret = vm_stop_force_state(state);
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trace_vmstate_downtime_checkpoint("src-vm-stopped");
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return ret;
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}
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void migration_object_init(void)
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{
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/* This can only be called once. */
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assert(!current_migration);
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current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
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/*
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* Init the migrate incoming object as well no matter whether
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* we'll use it or not.
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*/
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assert(!current_incoming);
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current_incoming = g_new0(MigrationIncomingState, 1);
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current_incoming->state = MIGRATION_STATUS_NONE;
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current_incoming->postcopy_remote_fds =
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g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD));
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qemu_mutex_init(¤t_incoming->rp_mutex);
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qemu_mutex_init(¤t_incoming->postcopy_prio_thread_mutex);
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qemu_event_init(¤t_incoming->main_thread_load_event, false);
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qemu_sem_init(¤t_incoming->postcopy_pause_sem_dst, 0);
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qemu_sem_init(¤t_incoming->postcopy_pause_sem_fault, 0);
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qemu_sem_init(¤t_incoming->postcopy_pause_sem_fast_load, 0);
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qemu_sem_init(¤t_incoming->postcopy_qemufile_dst_done, 0);
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qemu_mutex_init(¤t_incoming->page_request_mutex);
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qemu_cond_init(¤t_incoming->page_request_cond);
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current_incoming->page_requested = g_tree_new(page_request_addr_cmp);
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migration_object_check(current_migration, &error_fatal);
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blk_mig_init();
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ram_mig_init();
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dirty_bitmap_mig_init();
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}
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void migration_cancel(const Error *error)
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{
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if (error) {
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migrate_set_error(current_migration, error);
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}
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if (migrate_dirty_limit()) {
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qmp_cancel_vcpu_dirty_limit(false, -1, NULL);
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}
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migrate_fd_cancel(current_migration);
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}
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void migration_shutdown(void)
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{
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/*
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* When the QEMU main thread exit, the COLO thread
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* may wait a semaphore. So, we should wakeup the
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* COLO thread before migration shutdown.
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*/
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colo_shutdown();
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/*
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* Cancel the current migration - that will (eventually)
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* stop the migration using this structure
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*/
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migration_cancel(NULL);
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object_unref(OBJECT(current_migration));
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/*
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* Cancel outgoing migration of dirty bitmaps. It should
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* at least unref used block nodes.
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*/
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dirty_bitmap_mig_cancel_outgoing();
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/*
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* Cancel incoming migration of dirty bitmaps. Dirty bitmaps
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* are non-critical data, and their loss never considered as
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* something serious.
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*/
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dirty_bitmap_mig_cancel_incoming();
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}
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/* For outgoing */
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MigrationState *migrate_get_current(void)
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{
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/* This can only be called after the object created. */
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assert(current_migration);
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return current_migration;
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}
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MigrationIncomingState *migration_incoming_get_current(void)
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{
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assert(current_incoming);
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return current_incoming;
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}
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void migration_incoming_transport_cleanup(MigrationIncomingState *mis)
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{
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if (mis->socket_address_list) {
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qapi_free_SocketAddressList(mis->socket_address_list);
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mis->socket_address_list = NULL;
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}
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if (mis->transport_cleanup) {
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mis->transport_cleanup(mis->transport_data);
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mis->transport_data = mis->transport_cleanup = NULL;
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}
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}
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void migration_incoming_state_destroy(void)
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{
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struct MigrationIncomingState *mis = migration_incoming_get_current();
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multifd_load_cleanup();
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compress_threads_load_cleanup();
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if (mis->to_src_file) {
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/* Tell source that we are done */
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migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
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qemu_fclose(mis->to_src_file);
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mis->to_src_file = NULL;
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}
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if (mis->from_src_file) {
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migration_ioc_unregister_yank_from_file(mis->from_src_file);
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qemu_fclose(mis->from_src_file);
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mis->from_src_file = NULL;
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}
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if (mis->postcopy_remote_fds) {
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g_array_free(mis->postcopy_remote_fds, TRUE);
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mis->postcopy_remote_fds = NULL;
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}
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migration_incoming_transport_cleanup(mis);
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qemu_event_reset(&mis->main_thread_load_event);
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if (mis->page_requested) {
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g_tree_destroy(mis->page_requested);
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mis->page_requested = NULL;
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}
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if (mis->postcopy_qemufile_dst) {
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migration_ioc_unregister_yank_from_file(mis->postcopy_qemufile_dst);
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qemu_fclose(mis->postcopy_qemufile_dst);
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mis->postcopy_qemufile_dst = NULL;
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}
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yank_unregister_instance(MIGRATION_YANK_INSTANCE);
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}
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static void migrate_generate_event(int new_state)
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{
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if (migrate_events()) {
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qapi_event_send_migration(new_state);
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}
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}
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/*
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* Send a message on the return channel back to the source
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* of the migration.
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*/
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static int migrate_send_rp_message(MigrationIncomingState *mis,
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enum mig_rp_message_type message_type,
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uint16_t len, void *data)
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{
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int ret = 0;
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trace_migrate_send_rp_message((int)message_type, len);
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QEMU_LOCK_GUARD(&mis->rp_mutex);
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/*
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* It's possible that the file handle got lost due to network
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* failures.
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*/
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if (!mis->to_src_file) {
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ret = -EIO;
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return ret;
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}
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qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
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qemu_put_be16(mis->to_src_file, len);
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qemu_put_buffer(mis->to_src_file, data, len);
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return qemu_fflush(mis->to_src_file);
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}
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/* Request one page from the source VM at the given start address.
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* rb: the RAMBlock to request the page in
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* Start: Address offset within the RB
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* Len: Length in bytes required - must be a multiple of pagesize
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*/
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int migrate_send_rp_message_req_pages(MigrationIncomingState *mis,
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RAMBlock *rb, ram_addr_t start)
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{
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uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
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size_t msglen = 12; /* start + len */
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size_t len = qemu_ram_pagesize(rb);
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enum mig_rp_message_type msg_type;
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const char *rbname;
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int rbname_len;
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*(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
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*(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
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/*
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* We maintain the last ramblock that we requested for page. Note that we
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* don't need locking because this function will only be called within the
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* postcopy ram fault thread.
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*/
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if (rb != mis->last_rb) {
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mis->last_rb = rb;
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rbname = qemu_ram_get_idstr(rb);
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rbname_len = strlen(rbname);
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assert(rbname_len < 256);
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bufc[msglen++] = rbname_len;
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memcpy(bufc + msglen, rbname, rbname_len);
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msglen += rbname_len;
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msg_type = MIG_RP_MSG_REQ_PAGES_ID;
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} else {
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msg_type = MIG_RP_MSG_REQ_PAGES;
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}
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return migrate_send_rp_message(mis, msg_type, msglen, bufc);
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}
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int migrate_send_rp_req_pages(MigrationIncomingState *mis,
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RAMBlock *rb, ram_addr_t start, uint64_t haddr)
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{
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void *aligned = (void *)(uintptr_t)ROUND_DOWN(haddr, qemu_ram_pagesize(rb));
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bool received = false;
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WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
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received = ramblock_recv_bitmap_test_byte_offset(rb, start);
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if (!received && !g_tree_lookup(mis->page_requested, aligned)) {
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/*
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* The page has not been received, and it's not yet in the page
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* request list. Queue it. Set the value of element to 1, so that
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* things like g_tree_lookup() will return TRUE (1) when found.
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*/
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g_tree_insert(mis->page_requested, aligned, (gpointer)1);
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qatomic_inc(&mis->page_requested_count);
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trace_postcopy_page_req_add(aligned, mis->page_requested_count);
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}
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}
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/*
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* If the page is there, skip sending the message. We don't even need the
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* lock because as long as the page arrived, it'll be there forever.
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*/
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if (received) {
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return 0;
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}
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return migrate_send_rp_message_req_pages(mis, rb, start);
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}
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static bool migration_colo_enabled;
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bool migration_incoming_colo_enabled(void)
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{
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return migration_colo_enabled;
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}
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void migration_incoming_disable_colo(void)
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{
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ram_block_discard_disable(false);
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migration_colo_enabled = false;
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}
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int migration_incoming_enable_colo(void)
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{
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#ifndef CONFIG_REPLICATION
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error_report("ENABLE_COLO command come in migration stream, but COLO "
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"module is not built in");
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return -ENOTSUP;
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#endif
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if (!migrate_colo()) {
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error_report("ENABLE_COLO command come in migration stream, but c-colo "
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"capability is not set");
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return -EINVAL;
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}
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if (ram_block_discard_disable(true)) {
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error_report("COLO: cannot disable RAM discard");
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return -EBUSY;
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}
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migration_colo_enabled = true;
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return 0;
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}
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void migrate_add_address(SocketAddress *address)
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{
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MigrationIncomingState *mis = migration_incoming_get_current();
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QAPI_LIST_PREPEND(mis->socket_address_list,
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QAPI_CLONE(SocketAddress, address));
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}
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static bool migrate_uri_parse(const char *uri,
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MigrationAddress **channel,
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Error **errp)
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{
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g_autoptr(MigrationAddress) addr = g_new0(MigrationAddress, 1);
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SocketAddress *saddr = NULL;
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InetSocketAddress *isock = &addr->u.rdma;
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strList **tail = &addr->u.exec.args;
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if (strstart(uri, "exec:", NULL)) {
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addr->transport = MIGRATION_ADDRESS_TYPE_EXEC;
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#ifdef WIN32
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QAPI_LIST_APPEND(tail, g_strdup(exec_get_cmd_path()));
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QAPI_LIST_APPEND(tail, g_strdup("/c"));
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#else
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QAPI_LIST_APPEND(tail, g_strdup("/bin/sh"));
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QAPI_LIST_APPEND(tail, g_strdup("-c"));
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#endif
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QAPI_LIST_APPEND(tail, g_strdup(uri + strlen("exec:")));
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} else if (strstart(uri, "rdma:", NULL)) {
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if (inet_parse(isock, uri + strlen("rdma:"), errp)) {
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qapi_free_InetSocketAddress(isock);
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|
return false;
|
|
}
|
|
addr->transport = MIGRATION_ADDRESS_TYPE_RDMA;
|
|
} else if (strstart(uri, "tcp:", NULL) ||
|
|
strstart(uri, "unix:", NULL) ||
|
|
strstart(uri, "vsock:", NULL) ||
|
|
strstart(uri, "fd:", NULL)) {
|
|
addr->transport = MIGRATION_ADDRESS_TYPE_SOCKET;
|
|
saddr = socket_parse(uri, errp);
|
|
if (!saddr) {
|
|
return false;
|
|
}
|
|
addr->u.socket.type = saddr->type;
|
|
addr->u.socket.u = saddr->u;
|
|
} else if (strstart(uri, "file:", NULL)) {
|
|
addr->transport = MIGRATION_ADDRESS_TYPE_FILE;
|
|
addr->u.file.filename = g_strdup(uri + strlen("file:"));
|
|
if (file_parse_offset(addr->u.file.filename, &addr->u.file.offset,
|
|
errp)) {
|
|
return false;
|
|
}
|
|
} else {
|
|
error_setg(errp, "unknown migration protocol: %s", uri);
|
|
return false;
|
|
}
|
|
|
|
*channel = g_steal_pointer(&addr);
|
|
return true;
|
|
}
|
|
|
|
static void qemu_start_incoming_migration(const char *uri, Error **errp)
|
|
{
|
|
const char *p = NULL;
|
|
g_autoptr(MigrationAddress) channel = NULL;
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
/* URI is not suitable for migration? */
|
|
if (!migration_channels_and_uri_compatible(uri, errp)) {
|
|
return;
|
|
}
|
|
|
|
if (uri && !migrate_uri_parse(uri, &channel, errp)) {
|
|
return;
|
|
}
|
|
|
|
migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
|
|
MIGRATION_STATUS_SETUP);
|
|
|
|
if (channel->transport == MIGRATION_ADDRESS_TYPE_SOCKET) {
|
|
SocketAddress *saddr = &channel->u.socket;
|
|
if (saddr->type == SOCKET_ADDRESS_TYPE_INET ||
|
|
saddr->type == SOCKET_ADDRESS_TYPE_UNIX ||
|
|
saddr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
|
|
socket_start_incoming_migration(saddr, errp);
|
|
} else if (saddr->type == SOCKET_ADDRESS_TYPE_FD) {
|
|
fd_start_incoming_migration(saddr->u.fd.str, errp);
|
|
}
|
|
#ifdef CONFIG_RDMA
|
|
} else if (strstart(uri, "rdma:", &p)) {
|
|
if (migrate_compress()) {
|
|
error_setg(errp, "RDMA and compression can't be used together");
|
|
return;
|
|
}
|
|
if (migrate_xbzrle()) {
|
|
error_setg(errp, "RDMA and XBZRLE can't be used together");
|
|
return;
|
|
}
|
|
if (migrate_multifd()) {
|
|
error_setg(errp, "RDMA and multifd can't be used together");
|
|
return;
|
|
}
|
|
rdma_start_incoming_migration(p, errp);
|
|
#endif
|
|
} else if (strstart(uri, "exec:", &p)) {
|
|
exec_start_incoming_migration(p, errp);
|
|
} else if (strstart(uri, "file:", &p)) {
|
|
file_start_incoming_migration(p, errp);
|
|
} else {
|
|
error_setg(errp, "unknown migration protocol: %s", uri);
|
|
}
|
|
}
|
|
|
|
static void process_incoming_migration_bh(void *opaque)
|
|
{
|
|
Error *local_err = NULL;
|
|
MigrationIncomingState *mis = opaque;
|
|
|
|
trace_vmstate_downtime_checkpoint("dst-precopy-bh-enter");
|
|
|
|
/* If capability late_block_activate is set:
|
|
* Only fire up the block code now if we're going to restart the
|
|
* VM, else 'cont' will do it.
|
|
* This causes file locking to happen; so we don't want it to happen
|
|
* unless we really are starting the VM.
|
|
*/
|
|
if (!migrate_late_block_activate() ||
|
|
(autostart && (!global_state_received() ||
|
|
global_state_get_runstate() == RUN_STATE_RUNNING))) {
|
|
/* Make sure all file formats throw away their mutable metadata.
|
|
* If we get an error here, just don't restart the VM yet. */
|
|
bdrv_activate_all(&local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
local_err = NULL;
|
|
autostart = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This must happen after all error conditions are dealt with and
|
|
* we're sure the VM is going to be running on this host.
|
|
*/
|
|
qemu_announce_self(&mis->announce_timer, migrate_announce_params());
|
|
|
|
trace_vmstate_downtime_checkpoint("dst-precopy-bh-announced");
|
|
|
|
multifd_load_shutdown();
|
|
|
|
dirty_bitmap_mig_before_vm_start();
|
|
|
|
if (!global_state_received() ||
|
|
global_state_get_runstate() == RUN_STATE_RUNNING) {
|
|
if (autostart) {
|
|
vm_start();
|
|
} else {
|
|
runstate_set(RUN_STATE_PAUSED);
|
|
}
|
|
} else if (migration_incoming_colo_enabled()) {
|
|
migration_incoming_disable_colo();
|
|
vm_start();
|
|
} else {
|
|
runstate_set(global_state_get_runstate());
|
|
}
|
|
trace_vmstate_downtime_checkpoint("dst-precopy-bh-vm-started");
|
|
/*
|
|
* This must happen after any state changes since as soon as an external
|
|
* observer sees this event they might start to prod at the VM assuming
|
|
* it's ready to use.
|
|
*/
|
|
migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
|
|
MIGRATION_STATUS_COMPLETED);
|
|
qemu_bh_delete(mis->bh);
|
|
migration_incoming_state_destroy();
|
|
}
|
|
|
|
static void coroutine_fn
|
|
process_incoming_migration_co(void *opaque)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
PostcopyState ps;
|
|
int ret;
|
|
|
|
assert(mis->from_src_file);
|
|
|
|
if (compress_threads_load_setup(mis->from_src_file)) {
|
|
error_report("Failed to setup decompress threads");
|
|
goto fail;
|
|
}
|
|
|
|
mis->largest_page_size = qemu_ram_pagesize_largest();
|
|
postcopy_state_set(POSTCOPY_INCOMING_NONE);
|
|
migrate_set_state(&mis->state, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_ACTIVE);
|
|
|
|
mis->loadvm_co = qemu_coroutine_self();
|
|
ret = qemu_loadvm_state(mis->from_src_file);
|
|
mis->loadvm_co = NULL;
|
|
|
|
trace_vmstate_downtime_checkpoint("dst-precopy-loadvm-completed");
|
|
|
|
ps = postcopy_state_get();
|
|
trace_process_incoming_migration_co_end(ret, ps);
|
|
if (ps != POSTCOPY_INCOMING_NONE) {
|
|
if (ps == POSTCOPY_INCOMING_ADVISE) {
|
|
/*
|
|
* Where a migration had postcopy enabled (and thus went to advise)
|
|
* but managed to complete within the precopy period, we can use
|
|
* the normal exit.
|
|
*/
|
|
postcopy_ram_incoming_cleanup(mis);
|
|
} else if (ret >= 0) {
|
|
/*
|
|
* Postcopy was started, cleanup should happen at the end of the
|
|
* postcopy thread.
|
|
*/
|
|
trace_process_incoming_migration_co_postcopy_end_main();
|
|
return;
|
|
}
|
|
/* Else if something went wrong then just fall out of the normal exit */
|
|
}
|
|
|
|
if (ret < 0) {
|
|
error_report("load of migration failed: %s", strerror(-ret));
|
|
goto fail;
|
|
}
|
|
|
|
if (colo_incoming_co() < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
|
|
qemu_bh_schedule(mis->bh);
|
|
return;
|
|
fail:
|
|
migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
|
|
MIGRATION_STATUS_FAILED);
|
|
qemu_fclose(mis->from_src_file);
|
|
|
|
multifd_load_cleanup();
|
|
compress_threads_load_cleanup();
|
|
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/**
|
|
* migration_incoming_setup: Setup incoming migration
|
|
* @f: file for main migration channel
|
|
* @errp: where to put errors
|
|
*
|
|
* Returns: %true on success, %false on error.
|
|
*/
|
|
static bool migration_incoming_setup(QEMUFile *f, Error **errp)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
if (!mis->from_src_file) {
|
|
mis->from_src_file = f;
|
|
}
|
|
qemu_file_set_blocking(f, false);
|
|
return true;
|
|
}
|
|
|
|
void migration_incoming_process(void)
|
|
{
|
|
Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
|
|
qemu_coroutine_enter(co);
|
|
}
|
|
|
|
/* Returns true if recovered from a paused migration, otherwise false */
|
|
static bool postcopy_try_recover(void)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
|
|
/* Resumed from a paused postcopy migration */
|
|
|
|
/* This should be set already in migration_incoming_setup() */
|
|
assert(mis->from_src_file);
|
|
/* Postcopy has standalone thread to do vm load */
|
|
qemu_file_set_blocking(mis->from_src_file, true);
|
|
|
|
/* Re-configure the return path */
|
|
mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
|
|
|
|
migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
|
|
MIGRATION_STATUS_POSTCOPY_RECOVER);
|
|
|
|
/*
|
|
* Here, we only wake up the main loading thread (while the
|
|
* rest threads will still be waiting), so that we can receive
|
|
* commands from source now, and answer it if needed. The
|
|
* rest threads will be woken up afterwards until we are sure
|
|
* that source is ready to reply to page requests.
|
|
*/
|
|
qemu_sem_post(&mis->postcopy_pause_sem_dst);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void migration_fd_process_incoming(QEMUFile *f, Error **errp)
|
|
{
|
|
if (!migration_incoming_setup(f, errp)) {
|
|
return;
|
|
}
|
|
if (postcopy_try_recover()) {
|
|
return;
|
|
}
|
|
migration_incoming_process();
|
|
}
|
|
|
|
/*
|
|
* Returns true when we want to start a new incoming migration process,
|
|
* false otherwise.
|
|
*/
|
|
static bool migration_should_start_incoming(bool main_channel)
|
|
{
|
|
/* Multifd doesn't start unless all channels are established */
|
|
if (migrate_multifd()) {
|
|
return migration_has_all_channels();
|
|
}
|
|
|
|
/* Preempt channel only starts when the main channel is created */
|
|
if (migrate_postcopy_preempt()) {
|
|
return main_channel;
|
|
}
|
|
|
|
/*
|
|
* For all the rest types of migration, we should only reach here when
|
|
* it's the main channel that's being created, and we should always
|
|
* proceed with this channel.
|
|
*/
|
|
assert(main_channel);
|
|
return true;
|
|
}
|
|
|
|
void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
Error *local_err = NULL;
|
|
QEMUFile *f;
|
|
bool default_channel = true;
|
|
uint32_t channel_magic = 0;
|
|
int ret = 0;
|
|
|
|
if (migrate_multifd() && !migrate_postcopy_ram() &&
|
|
qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) {
|
|
/*
|
|
* With multiple channels, it is possible that we receive channels
|
|
* out of order on destination side, causing incorrect mapping of
|
|
* source channels on destination side. Check channel MAGIC to
|
|
* decide type of channel. Please note this is best effort, postcopy
|
|
* preempt channel does not send any magic number so avoid it for
|
|
* postcopy live migration. Also tls live migration already does
|
|
* tls handshake while initializing main channel so with tls this
|
|
* issue is not possible.
|
|
*/
|
|
ret = migration_channel_read_peek(ioc, (void *)&channel_magic,
|
|
sizeof(channel_magic), &local_err);
|
|
|
|
if (ret != 0) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
|
|
default_channel = (channel_magic == cpu_to_be32(QEMU_VM_FILE_MAGIC));
|
|
} else {
|
|
default_channel = !mis->from_src_file;
|
|
}
|
|
|
|
if (multifd_load_setup(errp) != 0) {
|
|
error_setg(errp, "Failed to setup multifd channels");
|
|
return;
|
|
}
|
|
|
|
if (default_channel) {
|
|
f = qemu_file_new_input(ioc);
|
|
|
|
if (!migration_incoming_setup(f, errp)) {
|
|
return;
|
|
}
|
|
} else {
|
|
/* Multiple connections */
|
|
assert(migration_needs_multiple_sockets());
|
|
if (migrate_multifd()) {
|
|
multifd_recv_new_channel(ioc, &local_err);
|
|
} else {
|
|
assert(migrate_postcopy_preempt());
|
|
f = qemu_file_new_input(ioc);
|
|
postcopy_preempt_new_channel(mis, f);
|
|
}
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (migration_should_start_incoming(default_channel)) {
|
|
/* If it's a recovery, we're done */
|
|
if (postcopy_try_recover()) {
|
|
return;
|
|
}
|
|
migration_incoming_process();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @migration_has_all_channels: We have received all channels that we need
|
|
*
|
|
* Returns true when we have got connections to all the channels that
|
|
* we need for migration.
|
|
*/
|
|
bool migration_has_all_channels(void)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
if (!mis->from_src_file) {
|
|
return false;
|
|
}
|
|
|
|
if (migrate_multifd()) {
|
|
return multifd_recv_all_channels_created();
|
|
}
|
|
|
|
if (migrate_postcopy_preempt()) {
|
|
return mis->postcopy_qemufile_dst != NULL;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
int migrate_send_rp_switchover_ack(MigrationIncomingState *mis)
|
|
{
|
|
return migrate_send_rp_message(mis, MIG_RP_MSG_SWITCHOVER_ACK, 0, NULL);
|
|
}
|
|
|
|
/*
|
|
* Send a 'SHUT' message on the return channel with the given value
|
|
* to indicate that we've finished with the RP. Non-0 value indicates
|
|
* error.
|
|
*/
|
|
void migrate_send_rp_shut(MigrationIncomingState *mis,
|
|
uint32_t value)
|
|
{
|
|
uint32_t buf;
|
|
|
|
buf = cpu_to_be32(value);
|
|
migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
|
|
}
|
|
|
|
/*
|
|
* Send a 'PONG' message on the return channel with the given value
|
|
* (normally in response to a 'PING')
|
|
*/
|
|
void migrate_send_rp_pong(MigrationIncomingState *mis,
|
|
uint32_t value)
|
|
{
|
|
uint32_t buf;
|
|
|
|
buf = cpu_to_be32(value);
|
|
migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
|
|
}
|
|
|
|
void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
|
|
char *block_name)
|
|
{
|
|
char buf[512];
|
|
int len;
|
|
int64_t res;
|
|
|
|
/*
|
|
* First, we send the header part. It contains only the len of
|
|
* idstr, and the idstr itself.
|
|
*/
|
|
len = strlen(block_name);
|
|
buf[0] = len;
|
|
memcpy(buf + 1, block_name, len);
|
|
|
|
if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
|
|
error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
|
|
__func__);
|
|
return;
|
|
}
|
|
|
|
migrate_send_rp_message(mis, MIG_RP_MSG_RECV_BITMAP, len + 1, buf);
|
|
|
|
/*
|
|
* Next, we dump the received bitmap to the stream.
|
|
*
|
|
* TODO: currently we are safe since we are the only one that is
|
|
* using the to_src_file handle (fault thread is still paused),
|
|
* and it's ok even not taking the mutex. However the best way is
|
|
* to take the lock before sending the message header, and release
|
|
* the lock after sending the bitmap.
|
|
*/
|
|
qemu_mutex_lock(&mis->rp_mutex);
|
|
res = ramblock_recv_bitmap_send(mis->to_src_file, block_name);
|
|
qemu_mutex_unlock(&mis->rp_mutex);
|
|
|
|
trace_migrate_send_rp_recv_bitmap(block_name, res);
|
|
}
|
|
|
|
void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value)
|
|
{
|
|
uint32_t buf;
|
|
|
|
buf = cpu_to_be32(value);
|
|
migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf);
|
|
}
|
|
|
|
/*
|
|
* Return true if we're already in the middle of a migration
|
|
* (i.e. any of the active or setup states)
|
|
*/
|
|
bool migration_is_setup_or_active(int state)
|
|
{
|
|
switch (state) {
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_PAUSED:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
case MIGRATION_STATUS_SETUP:
|
|
case MIGRATION_STATUS_PRE_SWITCHOVER:
|
|
case MIGRATION_STATUS_DEVICE:
|
|
case MIGRATION_STATUS_WAIT_UNPLUG:
|
|
case MIGRATION_STATUS_COLO:
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
|
|
}
|
|
}
|
|
|
|
bool migration_is_running(int state)
|
|
{
|
|
switch (state) {
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_PAUSED:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
case MIGRATION_STATUS_SETUP:
|
|
case MIGRATION_STATUS_PRE_SWITCHOVER:
|
|
case MIGRATION_STATUS_DEVICE:
|
|
case MIGRATION_STATUS_WAIT_UNPLUG:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
|
|
}
|
|
}
|
|
|
|
static bool migrate_show_downtime(MigrationState *s)
|
|
{
|
|
return (s->state == MIGRATION_STATUS_COMPLETED) || migration_in_postcopy();
|
|
}
|
|
|
|
static void populate_time_info(MigrationInfo *info, MigrationState *s)
|
|
{
|
|
info->has_status = true;
|
|
info->has_setup_time = true;
|
|
info->setup_time = s->setup_time;
|
|
|
|
if (s->state == MIGRATION_STATUS_COMPLETED) {
|
|
info->has_total_time = true;
|
|
info->total_time = s->total_time;
|
|
} else {
|
|
info->has_total_time = true;
|
|
info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
|
|
s->start_time;
|
|
}
|
|
|
|
if (migrate_show_downtime(s)) {
|
|
info->has_downtime = true;
|
|
info->downtime = s->downtime;
|
|
} else {
|
|
info->has_expected_downtime = true;
|
|
info->expected_downtime = s->expected_downtime;
|
|
}
|
|
}
|
|
|
|
static void populate_ram_info(MigrationInfo *info, MigrationState *s)
|
|
{
|
|
size_t page_size = qemu_target_page_size();
|
|
|
|
info->ram = g_malloc0(sizeof(*info->ram));
|
|
info->ram->transferred = migration_transferred_bytes();
|
|
info->ram->total = ram_bytes_total();
|
|
info->ram->duplicate = stat64_get(&mig_stats.zero_pages);
|
|
/* legacy value. It is not used anymore */
|
|
info->ram->skipped = 0;
|
|
info->ram->normal = stat64_get(&mig_stats.normal_pages);
|
|
info->ram->normal_bytes = info->ram->normal * page_size;
|
|
info->ram->mbps = s->mbps;
|
|
info->ram->dirty_sync_count =
|
|
stat64_get(&mig_stats.dirty_sync_count);
|
|
info->ram->dirty_sync_missed_zero_copy =
|
|
stat64_get(&mig_stats.dirty_sync_missed_zero_copy);
|
|
info->ram->postcopy_requests =
|
|
stat64_get(&mig_stats.postcopy_requests);
|
|
info->ram->page_size = page_size;
|
|
info->ram->multifd_bytes = stat64_get(&mig_stats.multifd_bytes);
|
|
info->ram->pages_per_second = s->pages_per_second;
|
|
info->ram->precopy_bytes = stat64_get(&mig_stats.precopy_bytes);
|
|
info->ram->downtime_bytes = stat64_get(&mig_stats.downtime_bytes);
|
|
info->ram->postcopy_bytes = stat64_get(&mig_stats.postcopy_bytes);
|
|
|
|
if (migrate_xbzrle()) {
|
|
info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
|
|
info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
|
|
info->xbzrle_cache->bytes = xbzrle_counters.bytes;
|
|
info->xbzrle_cache->pages = xbzrle_counters.pages;
|
|
info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss;
|
|
info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate;
|
|
info->xbzrle_cache->encoding_rate = xbzrle_counters.encoding_rate;
|
|
info->xbzrle_cache->overflow = xbzrle_counters.overflow;
|
|
}
|
|
|
|
populate_compress(info);
|
|
|
|
if (cpu_throttle_active()) {
|
|
info->has_cpu_throttle_percentage = true;
|
|
info->cpu_throttle_percentage = cpu_throttle_get_percentage();
|
|
}
|
|
|
|
if (s->state != MIGRATION_STATUS_COMPLETED) {
|
|
info->ram->remaining = ram_bytes_remaining();
|
|
info->ram->dirty_pages_rate =
|
|
stat64_get(&mig_stats.dirty_pages_rate);
|
|
}
|
|
|
|
if (migrate_dirty_limit() && dirtylimit_in_service()) {
|
|
info->has_dirty_limit_throttle_time_per_round = true;
|
|
info->dirty_limit_throttle_time_per_round =
|
|
dirtylimit_throttle_time_per_round();
|
|
|
|
info->has_dirty_limit_ring_full_time = true;
|
|
info->dirty_limit_ring_full_time = dirtylimit_ring_full_time();
|
|
}
|
|
}
|
|
|
|
static void populate_disk_info(MigrationInfo *info)
|
|
{
|
|
if (blk_mig_active()) {
|
|
info->disk = g_malloc0(sizeof(*info->disk));
|
|
info->disk->transferred = blk_mig_bytes_transferred();
|
|
info->disk->remaining = blk_mig_bytes_remaining();
|
|
info->disk->total = blk_mig_bytes_total();
|
|
}
|
|
}
|
|
|
|
static void fill_source_migration_info(MigrationInfo *info)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
int state = qatomic_read(&s->state);
|
|
GSList *cur_blocker = migration_blockers[migrate_mode()];
|
|
|
|
info->blocked_reasons = NULL;
|
|
|
|
/*
|
|
* There are two types of reasons a migration might be blocked;
|
|
* a) devices marked in VMState as non-migratable, and
|
|
* b) Explicit migration blockers
|
|
* We need to add both of them here.
|
|
*/
|
|
qemu_savevm_non_migratable_list(&info->blocked_reasons);
|
|
|
|
while (cur_blocker) {
|
|
QAPI_LIST_PREPEND(info->blocked_reasons,
|
|
g_strdup(error_get_pretty(cur_blocker->data)));
|
|
cur_blocker = g_slist_next(cur_blocker);
|
|
}
|
|
info->has_blocked_reasons = info->blocked_reasons != NULL;
|
|
|
|
switch (state) {
|
|
case MIGRATION_STATUS_NONE:
|
|
/* no migration has happened ever */
|
|
/* do not overwrite destination migration status */
|
|
return;
|
|
case MIGRATION_STATUS_SETUP:
|
|
info->has_status = true;
|
|
info->has_total_time = false;
|
|
break;
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_PRE_SWITCHOVER:
|
|
case MIGRATION_STATUS_DEVICE:
|
|
case MIGRATION_STATUS_POSTCOPY_PAUSED:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
/* TODO add some postcopy stats */
|
|
populate_time_info(info, s);
|
|
populate_ram_info(info, s);
|
|
populate_disk_info(info);
|
|
migration_populate_vfio_info(info);
|
|
break;
|
|
case MIGRATION_STATUS_COLO:
|
|
info->has_status = true;
|
|
/* TODO: display COLO specific information (checkpoint info etc.) */
|
|
break;
|
|
case MIGRATION_STATUS_COMPLETED:
|
|
populate_time_info(info, s);
|
|
populate_ram_info(info, s);
|
|
migration_populate_vfio_info(info);
|
|
break;
|
|
case MIGRATION_STATUS_FAILED:
|
|
info->has_status = true;
|
|
break;
|
|
case MIGRATION_STATUS_CANCELLED:
|
|
info->has_status = true;
|
|
break;
|
|
case MIGRATION_STATUS_WAIT_UNPLUG:
|
|
info->has_status = true;
|
|
break;
|
|
}
|
|
info->status = state;
|
|
|
|
QEMU_LOCK_GUARD(&s->error_mutex);
|
|
if (s->error) {
|
|
info->error_desc = g_strdup(error_get_pretty(s->error));
|
|
}
|
|
}
|
|
|
|
static void fill_destination_migration_info(MigrationInfo *info)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
if (mis->socket_address_list) {
|
|
info->has_socket_address = true;
|
|
info->socket_address =
|
|
QAPI_CLONE(SocketAddressList, mis->socket_address_list);
|
|
}
|
|
|
|
switch (mis->state) {
|
|
case MIGRATION_STATUS_NONE:
|
|
return;
|
|
case MIGRATION_STATUS_SETUP:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
case MIGRATION_STATUS_CANCELLED:
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_PAUSED:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
case MIGRATION_STATUS_FAILED:
|
|
case MIGRATION_STATUS_COLO:
|
|
info->has_status = true;
|
|
break;
|
|
case MIGRATION_STATUS_COMPLETED:
|
|
info->has_status = true;
|
|
fill_destination_postcopy_migration_info(info);
|
|
break;
|
|
}
|
|
info->status = mis->state;
|
|
}
|
|
|
|
MigrationInfo *qmp_query_migrate(Error **errp)
|
|
{
|
|
MigrationInfo *info = g_malloc0(sizeof(*info));
|
|
|
|
fill_destination_migration_info(info);
|
|
fill_source_migration_info(info);
|
|
|
|
return info;
|
|
}
|
|
|
|
void qmp_migrate_start_postcopy(Error **errp)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
|
|
if (!migrate_postcopy()) {
|
|
error_setg(errp, "Enable postcopy with migrate_set_capability before"
|
|
" the start of migration");
|
|
return;
|
|
}
|
|
|
|
if (s->state == MIGRATION_STATUS_NONE) {
|
|
error_setg(errp, "Postcopy must be started after migration has been"
|
|
" started");
|
|
return;
|
|
}
|
|
/*
|
|
* we don't error if migration has finished since that would be racy
|
|
* with issuing this command.
|
|
*/
|
|
qatomic_set(&s->start_postcopy, true);
|
|
}
|
|
|
|
/* shared migration helpers */
|
|
|
|
void migrate_set_state(int *state, int old_state, int new_state)
|
|
{
|
|
assert(new_state < MIGRATION_STATUS__MAX);
|
|
if (qatomic_cmpxchg(state, old_state, new_state) == old_state) {
|
|
trace_migrate_set_state(MigrationStatus_str(new_state));
|
|
migrate_generate_event(new_state);
|
|
}
|
|
}
|
|
|
|
static void migrate_fd_cleanup(MigrationState *s)
|
|
{
|
|
qemu_bh_delete(s->cleanup_bh);
|
|
s->cleanup_bh = NULL;
|
|
|
|
g_free(s->hostname);
|
|
s->hostname = NULL;
|
|
json_writer_free(s->vmdesc);
|
|
s->vmdesc = NULL;
|
|
|
|
qemu_savevm_state_cleanup();
|
|
|
|
if (s->to_dst_file) {
|
|
QEMUFile *tmp;
|
|
|
|
trace_migrate_fd_cleanup();
|
|
qemu_mutex_unlock_iothread();
|
|
if (s->migration_thread_running) {
|
|
qemu_thread_join(&s->thread);
|
|
s->migration_thread_running = false;
|
|
}
|
|
qemu_mutex_lock_iothread();
|
|
|
|
multifd_save_cleanup();
|
|
qemu_mutex_lock(&s->qemu_file_lock);
|
|
tmp = s->to_dst_file;
|
|
s->to_dst_file = NULL;
|
|
qemu_mutex_unlock(&s->qemu_file_lock);
|
|
/*
|
|
* Close the file handle without the lock to make sure the
|
|
* critical section won't block for long.
|
|
*/
|
|
migration_ioc_unregister_yank_from_file(tmp);
|
|
qemu_fclose(tmp);
|
|
}
|
|
|
|
/*
|
|
* We already cleaned up to_dst_file, so errors from the return
|
|
* path might be due to that, ignore them.
|
|
*/
|
|
close_return_path_on_source(s);
|
|
|
|
assert(!migration_is_active(s));
|
|
|
|
if (s->state == MIGRATION_STATUS_CANCELLING) {
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
|
|
MIGRATION_STATUS_CANCELLED);
|
|
}
|
|
|
|
if (s->error) {
|
|
/* It is used on info migrate. We can't free it */
|
|
error_report_err(error_copy(s->error));
|
|
}
|
|
migration_call_notifiers(s);
|
|
block_cleanup_parameters();
|
|
yank_unregister_instance(MIGRATION_YANK_INSTANCE);
|
|
}
|
|
|
|
static void migrate_fd_cleanup_schedule(MigrationState *s)
|
|
{
|
|
/*
|
|
* Ref the state for bh, because it may be called when
|
|
* there're already no other refs
|
|
*/
|
|
object_ref(OBJECT(s));
|
|
qemu_bh_schedule(s->cleanup_bh);
|
|
}
|
|
|
|
static void migrate_fd_cleanup_bh(void *opaque)
|
|
{
|
|
MigrationState *s = opaque;
|
|
migrate_fd_cleanup(s);
|
|
object_unref(OBJECT(s));
|
|
}
|
|
|
|
void migrate_set_error(MigrationState *s, const Error *error)
|
|
{
|
|
QEMU_LOCK_GUARD(&s->error_mutex);
|
|
if (!s->error) {
|
|
s->error = error_copy(error);
|
|
}
|
|
}
|
|
|
|
bool migrate_has_error(MigrationState *s)
|
|
{
|
|
/* The lock is not helpful here, but still follow the rule */
|
|
QEMU_LOCK_GUARD(&s->error_mutex);
|
|
return qatomic_read(&s->error);
|
|
}
|
|
|
|
static void migrate_error_free(MigrationState *s)
|
|
{
|
|
QEMU_LOCK_GUARD(&s->error_mutex);
|
|
if (s->error) {
|
|
error_free(s->error);
|
|
s->error = NULL;
|
|
}
|
|
}
|
|
|
|
static void migrate_fd_error(MigrationState *s, const Error *error)
|
|
{
|
|
trace_migrate_fd_error(error_get_pretty(error));
|
|
assert(s->to_dst_file == NULL);
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_FAILED);
|
|
migrate_set_error(s, error);
|
|
}
|
|
|
|
static void migrate_fd_cancel(MigrationState *s)
|
|
{
|
|
int old_state ;
|
|
|
|
trace_migrate_fd_cancel();
|
|
|
|
WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) {
|
|
if (s->rp_state.from_dst_file) {
|
|
/* shutdown the rp socket, so causing the rp thread to shutdown */
|
|
qemu_file_shutdown(s->rp_state.from_dst_file);
|
|
}
|
|
}
|
|
|
|
do {
|
|
old_state = s->state;
|
|
if (!migration_is_running(old_state)) {
|
|
break;
|
|
}
|
|
/* If the migration is paused, kick it out of the pause */
|
|
if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) {
|
|
qemu_sem_post(&s->pause_sem);
|
|
}
|
|
migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
|
|
} while (s->state != MIGRATION_STATUS_CANCELLING);
|
|
|
|
/*
|
|
* If we're unlucky the migration code might be stuck somewhere in a
|
|
* send/write while the network has failed and is waiting to timeout;
|
|
* if we've got shutdown(2) available then we can force it to quit.
|
|
*/
|
|
if (s->state == MIGRATION_STATUS_CANCELLING) {
|
|
WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) {
|
|
if (s->to_dst_file) {
|
|
qemu_file_shutdown(s->to_dst_file);
|
|
}
|
|
}
|
|
}
|
|
if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
|
|
Error *local_err = NULL;
|
|
|
|
bdrv_activate_all(&local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
} else {
|
|
s->block_inactive = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
void migration_add_notifier(Notifier *notify,
|
|
void (*func)(Notifier *notifier, void *data))
|
|
{
|
|
notify->notify = func;
|
|
notifier_list_add(&migration_state_notifiers, notify);
|
|
}
|
|
|
|
void migration_remove_notifier(Notifier *notify)
|
|
{
|
|
if (notify->notify) {
|
|
notifier_remove(notify);
|
|
notify->notify = NULL;
|
|
}
|
|
}
|
|
|
|
void migration_call_notifiers(MigrationState *s)
|
|
{
|
|
notifier_list_notify(&migration_state_notifiers, s);
|
|
}
|
|
|
|
bool migration_in_setup(MigrationState *s)
|
|
{
|
|
return s->state == MIGRATION_STATUS_SETUP;
|
|
}
|
|
|
|
bool migration_has_finished(MigrationState *s)
|
|
{
|
|
return s->state == MIGRATION_STATUS_COMPLETED;
|
|
}
|
|
|
|
bool migration_has_failed(MigrationState *s)
|
|
{
|
|
return (s->state == MIGRATION_STATUS_CANCELLED ||
|
|
s->state == MIGRATION_STATUS_FAILED);
|
|
}
|
|
|
|
bool migration_in_postcopy(void)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
|
|
switch (s->state) {
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_PAUSED:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool migration_postcopy_is_alive(int state)
|
|
{
|
|
switch (state) {
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_RECOVER:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool migration_in_postcopy_after_devices(MigrationState *s)
|
|
{
|
|
return migration_in_postcopy() && s->postcopy_after_devices;
|
|
}
|
|
|
|
bool migration_in_incoming_postcopy(void)
|
|
{
|
|
PostcopyState ps = postcopy_state_get();
|
|
|
|
return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END;
|
|
}
|
|
|
|
bool migration_incoming_postcopy_advised(void)
|
|
{
|
|
PostcopyState ps = postcopy_state_get();
|
|
|
|
return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END;
|
|
}
|
|
|
|
bool migration_in_bg_snapshot(void)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
|
|
return migrate_background_snapshot() &&
|
|
migration_is_setup_or_active(s->state);
|
|
}
|
|
|
|
bool migration_is_idle(void)
|
|
{
|
|
MigrationState *s = current_migration;
|
|
|
|
if (!s) {
|
|
return true;
|
|
}
|
|
|
|
switch (s->state) {
|
|
case MIGRATION_STATUS_NONE:
|
|
case MIGRATION_STATUS_CANCELLED:
|
|
case MIGRATION_STATUS_COMPLETED:
|
|
case MIGRATION_STATUS_FAILED:
|
|
return true;
|
|
case MIGRATION_STATUS_SETUP:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_POSTCOPY_ACTIVE:
|
|
case MIGRATION_STATUS_COLO:
|
|
case MIGRATION_STATUS_PRE_SWITCHOVER:
|
|
case MIGRATION_STATUS_DEVICE:
|
|
case MIGRATION_STATUS_WAIT_UNPLUG:
|
|
return false;
|
|
case MIGRATION_STATUS__MAX:
|
|
g_assert_not_reached();
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool migration_is_active(MigrationState *s)
|
|
{
|
|
return (s->state == MIGRATION_STATUS_ACTIVE ||
|
|
s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
|
|
}
|
|
|
|
int migrate_init(MigrationState *s, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
ret = qemu_savevm_state_prepare(errp);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Reinitialise all migration state, except
|
|
* parameters/capabilities that the user set, and
|
|
* locks.
|
|
*/
|
|
s->cleanup_bh = 0;
|
|
s->vm_start_bh = 0;
|
|
s->to_dst_file = NULL;
|
|
s->state = MIGRATION_STATUS_NONE;
|
|
s->rp_state.from_dst_file = NULL;
|
|
s->mbps = 0.0;
|
|
s->pages_per_second = 0.0;
|
|
s->downtime = 0;
|
|
s->expected_downtime = 0;
|
|
s->setup_time = 0;
|
|
s->start_postcopy = false;
|
|
s->postcopy_after_devices = false;
|
|
s->migration_thread_running = false;
|
|
error_free(s->error);
|
|
s->error = NULL;
|
|
s->hostname = NULL;
|
|
s->vmdesc = NULL;
|
|
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
|
|
|
|
s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
|
|
s->total_time = 0;
|
|
s->vm_old_state = -1;
|
|
s->iteration_initial_bytes = 0;
|
|
s->threshold_size = 0;
|
|
s->switchover_acked = false;
|
|
s->rdma_migration = false;
|
|
/*
|
|
* set mig_stats memory to zero for a new migration
|
|
*/
|
|
memset(&mig_stats, 0, sizeof(mig_stats));
|
|
migration_reset_vfio_bytes_transferred();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool is_busy(Error **reasonp, Error **errp)
|
|
{
|
|
ERRP_GUARD();
|
|
|
|
/* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */
|
|
if (runstate_check(RUN_STATE_SAVE_VM) || !migration_is_idle()) {
|
|
error_propagate_prepend(errp, *reasonp,
|
|
"disallowing migration blocker "
|
|
"(migration/snapshot in progress) for: ");
|
|
*reasonp = NULL;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool is_only_migratable(Error **reasonp, Error **errp, int modes)
|
|
{
|
|
ERRP_GUARD();
|
|
|
|
if (only_migratable && (modes & BIT(MIG_MODE_NORMAL))) {
|
|
error_propagate_prepend(errp, *reasonp,
|
|
"disallowing migration blocker "
|
|
"(--only-migratable) for: ");
|
|
*reasonp = NULL;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static int get_modes(MigMode mode, va_list ap)
|
|
{
|
|
int modes = 0;
|
|
|
|
while (mode != -1 && mode != MIG_MODE_ALL) {
|
|
assert(mode >= MIG_MODE_NORMAL && mode < MIG_MODE__MAX);
|
|
modes |= BIT(mode);
|
|
mode = va_arg(ap, MigMode);
|
|
}
|
|
if (mode == MIG_MODE_ALL) {
|
|
modes = BIT(MIG_MODE__MAX) - 1;
|
|
}
|
|
return modes;
|
|
}
|
|
|
|
static int add_blockers(Error **reasonp, Error **errp, int modes)
|
|
{
|
|
for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
|
|
if (modes & BIT(mode)) {
|
|
migration_blockers[mode] = g_slist_prepend(migration_blockers[mode],
|
|
*reasonp);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int migrate_add_blocker(Error **reasonp, Error **errp)
|
|
{
|
|
return migrate_add_blocker_modes(reasonp, errp, MIG_MODE_ALL);
|
|
}
|
|
|
|
int migrate_add_blocker_normal(Error **reasonp, Error **errp)
|
|
{
|
|
return migrate_add_blocker_modes(reasonp, errp, MIG_MODE_NORMAL, -1);
|
|
}
|
|
|
|
int migrate_add_blocker_modes(Error **reasonp, Error **errp, MigMode mode, ...)
|
|
{
|
|
int modes;
|
|
va_list ap;
|
|
|
|
va_start(ap, mode);
|
|
modes = get_modes(mode, ap);
|
|
va_end(ap);
|
|
|
|
if (is_only_migratable(reasonp, errp, modes)) {
|
|
return -EACCES;
|
|
} else if (is_busy(reasonp, errp)) {
|
|
return -EBUSY;
|
|
}
|
|
return add_blockers(reasonp, errp, modes);
|
|
}
|
|
|
|
int migrate_add_blocker_internal(Error **reasonp, Error **errp)
|
|
{
|
|
int modes = BIT(MIG_MODE__MAX) - 1;
|
|
|
|
if (is_busy(reasonp, errp)) {
|
|
return -EBUSY;
|
|
}
|
|
return add_blockers(reasonp, errp, modes);
|
|
}
|
|
|
|
void migrate_del_blocker(Error **reasonp)
|
|
{
|
|
if (*reasonp) {
|
|
for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
|
|
migration_blockers[mode] = g_slist_remove(migration_blockers[mode],
|
|
*reasonp);
|
|
}
|
|
error_free(*reasonp);
|
|
*reasonp = NULL;
|
|
}
|
|
}
|
|
|
|
void qmp_migrate_incoming(const char *uri, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
static bool once = true;
|
|
|
|
if (!once) {
|
|
error_setg(errp, "The incoming migration has already been started");
|
|
return;
|
|
}
|
|
if (!runstate_check(RUN_STATE_INMIGRATE)) {
|
|
error_setg(errp, "'-incoming' was not specified on the command line");
|
|
return;
|
|
}
|
|
|
|
if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
|
|
return;
|
|
}
|
|
|
|
qemu_start_incoming_migration(uri, &local_err);
|
|
|
|
if (local_err) {
|
|
yank_unregister_instance(MIGRATION_YANK_INSTANCE);
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
|
|
once = false;
|
|
}
|
|
|
|
void qmp_migrate_recover(const char *uri, Error **errp)
|
|
{
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
|
|
/*
|
|
* Don't even bother to use ERRP_GUARD() as it _must_ always be set by
|
|
* callers (no one should ignore a recover failure); if there is, it's a
|
|
* programming error.
|
|
*/
|
|
assert(errp);
|
|
|
|
if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
|
|
error_setg(errp, "Migrate recover can only be run "
|
|
"when postcopy is paused.");
|
|
return;
|
|
}
|
|
|
|
/* If there's an existing transport, release it */
|
|
migration_incoming_transport_cleanup(mis);
|
|
|
|
/*
|
|
* Note that this call will never start a real migration; it will
|
|
* only re-setup the migration stream and poke existing migration
|
|
* to continue using that newly established channel.
|
|
*/
|
|
qemu_start_incoming_migration(uri, errp);
|
|
}
|
|
|
|
void qmp_migrate_pause(Error **errp)
|
|
{
|
|
MigrationState *ms = migrate_get_current();
|
|
MigrationIncomingState *mis = migration_incoming_get_current();
|
|
int ret = 0;
|
|
|
|
if (migration_postcopy_is_alive(ms->state)) {
|
|
/* Source side, during postcopy */
|
|
Error *error = NULL;
|
|
|
|
/* Tell the core migration that we're pausing */
|
|
error_setg(&error, "Postcopy migration is paused by the user");
|
|
migrate_set_error(ms, error);
|
|
error_free(error);
|
|
|
|
qemu_mutex_lock(&ms->qemu_file_lock);
|
|
if (ms->to_dst_file) {
|
|
ret = qemu_file_shutdown(ms->to_dst_file);
|
|
}
|
|
qemu_mutex_unlock(&ms->qemu_file_lock);
|
|
if (ret) {
|
|
error_setg(errp, "Failed to pause source migration");
|
|
}
|
|
|
|
/*
|
|
* Kick the migration thread out of any waiting windows (on behalf
|
|
* of the rp thread).
|
|
*/
|
|
migration_rp_kick(ms);
|
|
|
|
return;
|
|
}
|
|
|
|
if (migration_postcopy_is_alive(mis->state)) {
|
|
ret = qemu_file_shutdown(mis->from_src_file);
|
|
if (ret) {
|
|
error_setg(errp, "Failed to pause destination migration");
|
|
}
|
|
return;
|
|
}
|
|
|
|
error_setg(errp, "migrate-pause is currently only supported "
|
|
"during postcopy-active or postcopy-recover state");
|
|
}
|
|
|
|
bool migration_is_blocked(Error **errp)
|
|
{
|
|
GSList *blockers = migration_blockers[migrate_mode()];
|
|
|
|
if (qemu_savevm_state_blocked(errp)) {
|
|
return true;
|
|
}
|
|
|
|
if (blockers) {
|
|
error_propagate(errp, error_copy(blockers->data));
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Returns true if continue to migrate, or false if error detected */
|
|
static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
|
|
bool resume, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
|
|
if (blk_inc) {
|
|
warn_report("parameter 'inc' is deprecated;"
|
|
" use blockdev-mirror with NBD instead");
|
|
}
|
|
|
|
if (blk) {
|
|
warn_report("parameter 'blk' is deprecated;"
|
|
" use blockdev-mirror with NBD instead");
|
|
}
|
|
|
|
if (resume) {
|
|
if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
|
|
error_setg(errp, "Cannot resume if there is no "
|
|
"paused migration");
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Postcopy recovery won't work well with release-ram
|
|
* capability since release-ram will drop the page buffer as
|
|
* long as the page is put into the send buffer. So if there
|
|
* is a network failure happened, any page buffers that have
|
|
* not yet reached the destination VM but have already been
|
|
* sent from the source VM will be lost forever. Let's refuse
|
|
* the client from resuming such a postcopy migration.
|
|
* Luckily release-ram was designed to only be used when src
|
|
* and destination VMs are on the same host, so it should be
|
|
* fine.
|
|
*/
|
|
if (migrate_release_ram()) {
|
|
error_setg(errp, "Postcopy recovery cannot work "
|
|
"when release-ram capability is set");
|
|
return false;
|
|
}
|
|
|
|
/* This is a resume, skip init status */
|
|
return true;
|
|
}
|
|
|
|
if (migration_is_running(s->state)) {
|
|
error_setg(errp, QERR_MIGRATION_ACTIVE);
|
|
return false;
|
|
}
|
|
|
|
if (runstate_check(RUN_STATE_INMIGRATE)) {
|
|
error_setg(errp, "Guest is waiting for an incoming migration");
|
|
return false;
|
|
}
|
|
|
|
if (runstate_check(RUN_STATE_POSTMIGRATE)) {
|
|
error_setg(errp, "Can't migrate the vm that was paused due to "
|
|
"previous migration");
|
|
return false;
|
|
}
|
|
|
|
if (migration_is_blocked(errp)) {
|
|
return false;
|
|
}
|
|
|
|
if (blk || blk_inc) {
|
|
if (migrate_colo()) {
|
|
error_setg(errp, "No disk migration is required in COLO mode");
|
|
return false;
|
|
}
|
|
if (migrate_block() || migrate_block_incremental()) {
|
|
error_setg(errp, "Command options are incompatible with "
|
|
"current migration capabilities");
|
|
return false;
|
|
}
|
|
if (!migrate_cap_set(MIGRATION_CAPABILITY_BLOCK, true, &local_err)) {
|
|
error_propagate(errp, local_err);
|
|
return false;
|
|
}
|
|
s->must_remove_block_options = true;
|
|
}
|
|
|
|
if (blk_inc) {
|
|
migrate_set_block_incremental(true);
|
|
}
|
|
|
|
if (migrate_init(s, errp)) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void qmp_migrate(const char *uri, bool has_blk, bool blk,
|
|
bool has_inc, bool inc, bool has_detach, bool detach,
|
|
bool has_resume, bool resume, Error **errp)
|
|
{
|
|
bool resume_requested;
|
|
Error *local_err = NULL;
|
|
MigrationState *s = migrate_get_current();
|
|
const char *p = NULL;
|
|
g_autoptr(MigrationAddress) channel = NULL;
|
|
|
|
/* URI is not suitable for migration? */
|
|
if (!migration_channels_and_uri_compatible(uri, errp)) {
|
|
return;
|
|
}
|
|
|
|
if (!migrate_uri_parse(uri, &channel, errp)) {
|
|
return;
|
|
}
|
|
|
|
resume_requested = has_resume && resume;
|
|
if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
|
|
resume_requested, errp)) {
|
|
/* Error detected, put into errp */
|
|
return;
|
|
}
|
|
|
|
if (!resume_requested) {
|
|
if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (channel->transport == MIGRATION_ADDRESS_TYPE_SOCKET) {
|
|
SocketAddress *saddr = &channel->u.socket;
|
|
if (saddr->type == SOCKET_ADDRESS_TYPE_INET ||
|
|
saddr->type == SOCKET_ADDRESS_TYPE_UNIX ||
|
|
saddr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
|
|
socket_start_outgoing_migration(s, saddr, &local_err);
|
|
} else if (saddr->type == SOCKET_ADDRESS_TYPE_FD) {
|
|
fd_start_outgoing_migration(s, saddr->u.fd.str, &local_err);
|
|
}
|
|
#ifdef CONFIG_RDMA
|
|
} else if (strstart(uri, "rdma:", &p)) {
|
|
rdma_start_outgoing_migration(s, p, &local_err);
|
|
#endif
|
|
} else if (strstart(uri, "exec:", &p)) {
|
|
exec_start_outgoing_migration(s, p, &local_err);
|
|
} else if (strstart(uri, "file:", &p)) {
|
|
file_start_outgoing_migration(s, p, &local_err);
|
|
} else {
|
|
error_setg(&local_err, QERR_INVALID_PARAMETER_VALUE, "uri",
|
|
"a valid migration protocol");
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_FAILED);
|
|
block_cleanup_parameters();
|
|
}
|
|
|
|
if (local_err) {
|
|
if (!resume_requested) {
|
|
yank_unregister_instance(MIGRATION_YANK_INSTANCE);
|
|
}
|
|
migrate_fd_error(s, local_err);
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
|
|
void qmp_migrate_cancel(Error **errp)
|
|
{
|
|
migration_cancel(NULL);
|
|
}
|
|
|
|
void qmp_migrate_continue(MigrationStatus state, Error **errp)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
if (s->state != state) {
|
|
error_setg(errp, "Migration not in expected state: %s",
|
|
MigrationStatus_str(s->state));
|
|
return;
|
|
}
|
|
qemu_sem_post(&s->pause_sem);
|
|
}
|
|
|
|
int migration_rp_wait(MigrationState *s)
|
|
{
|
|
/* If migration has failure already, ignore the wait */
|
|
if (migrate_has_error(s)) {
|
|
return -1;
|
|
}
|
|
|
|
qemu_sem_wait(&s->rp_state.rp_sem);
|
|
|
|
/* After wait, double check that there's no failure */
|
|
if (migrate_has_error(s)) {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void migration_rp_kick(MigrationState *s)
|
|
{
|
|
qemu_sem_post(&s->rp_state.rp_sem);
|
|
}
|
|
|
|
static struct rp_cmd_args {
|
|
ssize_t len; /* -1 = variable */
|
|
const char *name;
|
|
} rp_cmd_args[] = {
|
|
[MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
|
|
[MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
|
|
[MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
|
|
[MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
|
|
[MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
|
|
[MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
|
|
[MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" },
|
|
[MIG_RP_MSG_SWITCHOVER_ACK] = { .len = 0, .name = "SWITCHOVER_ACK" },
|
|
[MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
|
|
};
|
|
|
|
/*
|
|
* Process a request for pages received on the return path,
|
|
* We're allowed to send more than requested (e.g. to round to our page size)
|
|
* and we don't need to send pages that have already been sent.
|
|
*/
|
|
static void
|
|
migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
|
|
ram_addr_t start, size_t len, Error **errp)
|
|
{
|
|
long our_host_ps = qemu_real_host_page_size();
|
|
|
|
trace_migrate_handle_rp_req_pages(rbname, start, len);
|
|
|
|
/*
|
|
* Since we currently insist on matching page sizes, just sanity check
|
|
* we're being asked for whole host pages.
|
|
*/
|
|
if (!QEMU_IS_ALIGNED(start, our_host_ps) ||
|
|
!QEMU_IS_ALIGNED(len, our_host_ps)) {
|
|
error_setg(errp, "MIG_RP_MSG_REQ_PAGES: Misaligned page request, start:"
|
|
RAM_ADDR_FMT " len: %zd", start, len);
|
|
return;
|
|
}
|
|
|
|
ram_save_queue_pages(rbname, start, len, errp);
|
|
}
|
|
|
|
static bool migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name,
|
|
Error **errp)
|
|
{
|
|
RAMBlock *block = qemu_ram_block_by_name(block_name);
|
|
|
|
if (!block) {
|
|
error_setg(errp, "MIG_RP_MSG_RECV_BITMAP has invalid block name '%s'",
|
|
block_name);
|
|
return false;
|
|
}
|
|
|
|
/* Fetch the received bitmap and refresh the dirty bitmap */
|
|
return ram_dirty_bitmap_reload(s, block, errp);
|
|
}
|
|
|
|
static bool migrate_handle_rp_resume_ack(MigrationState *s,
|
|
uint32_t value, Error **errp)
|
|
{
|
|
trace_source_return_path_thread_resume_ack(value);
|
|
|
|
if (value != MIGRATION_RESUME_ACK_VALUE) {
|
|
error_setg(errp, "illegal resume_ack value %"PRIu32, value);
|
|
return false;
|
|
}
|
|
|
|
/* Now both sides are active. */
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
|
|
MIGRATION_STATUS_POSTCOPY_ACTIVE);
|
|
|
|
/* Notify send thread that time to continue send pages */
|
|
migration_rp_kick(s);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Release ms->rp_state.from_dst_file (and postcopy_qemufile_src if
|
|
* existed) in a safe way.
|
|
*/
|
|
static void migration_release_dst_files(MigrationState *ms)
|
|
{
|
|
QEMUFile *file;
|
|
|
|
WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) {
|
|
/*
|
|
* Reset the from_dst_file pointer first before releasing it, as we
|
|
* can't block within lock section
|
|
*/
|
|
file = ms->rp_state.from_dst_file;
|
|
ms->rp_state.from_dst_file = NULL;
|
|
}
|
|
|
|
/*
|
|
* Do the same to postcopy fast path socket too if there is. No
|
|
* locking needed because this qemufile should only be managed by
|
|
* return path thread.
|
|
*/
|
|
if (ms->postcopy_qemufile_src) {
|
|
migration_ioc_unregister_yank_from_file(ms->postcopy_qemufile_src);
|
|
qemu_file_shutdown(ms->postcopy_qemufile_src);
|
|
qemu_fclose(ms->postcopy_qemufile_src);
|
|
ms->postcopy_qemufile_src = NULL;
|
|
}
|
|
|
|
qemu_fclose(file);
|
|
}
|
|
|
|
/*
|
|
* Handles messages sent on the return path towards the source VM
|
|
*
|
|
*/
|
|
static void *source_return_path_thread(void *opaque)
|
|
{
|
|
MigrationState *ms = opaque;
|
|
QEMUFile *rp = ms->rp_state.from_dst_file;
|
|
uint16_t header_len, header_type;
|
|
uint8_t buf[512];
|
|
uint32_t tmp32, sibling_error;
|
|
ram_addr_t start = 0; /* =0 to silence warning */
|
|
size_t len = 0, expected_len;
|
|
Error *err = NULL;
|
|
int res;
|
|
|
|
trace_source_return_path_thread_entry();
|
|
rcu_register_thread();
|
|
|
|
while (migration_is_setup_or_active(ms->state)) {
|
|
trace_source_return_path_thread_loop_top();
|
|
|
|
header_type = qemu_get_be16(rp);
|
|
header_len = qemu_get_be16(rp);
|
|
|
|
if (qemu_file_get_error(rp)) {
|
|
qemu_file_get_error_obj(rp, &err);
|
|
goto out;
|
|
}
|
|
|
|
if (header_type >= MIG_RP_MSG_MAX ||
|
|
header_type == MIG_RP_MSG_INVALID) {
|
|
error_setg(&err, "Received invalid message 0x%04x length 0x%04x",
|
|
header_type, header_len);
|
|
goto out;
|
|
}
|
|
|
|
if ((rp_cmd_args[header_type].len != -1 &&
|
|
header_len != rp_cmd_args[header_type].len) ||
|
|
header_len > sizeof(buf)) {
|
|
error_setg(&err, "Received '%s' message (0x%04x) with"
|
|
"incorrect length %d expecting %zu",
|
|
rp_cmd_args[header_type].name, header_type, header_len,
|
|
(size_t)rp_cmd_args[header_type].len);
|
|
goto out;
|
|
}
|
|
|
|
/* We know we've got a valid header by this point */
|
|
res = qemu_get_buffer(rp, buf, header_len);
|
|
if (res != header_len) {
|
|
error_setg(&err, "Failed reading data for message 0x%04x"
|
|
" read %d expected %d",
|
|
header_type, res, header_len);
|
|
goto out;
|
|
}
|
|
|
|
/* OK, we have the message and the data */
|
|
switch (header_type) {
|
|
case MIG_RP_MSG_SHUT:
|
|
sibling_error = ldl_be_p(buf);
|
|
trace_source_return_path_thread_shut(sibling_error);
|
|
if (sibling_error) {
|
|
error_setg(&err, "Sibling indicated error %d", sibling_error);
|
|
}
|
|
/*
|
|
* We'll let the main thread deal with closing the RP
|
|
* we could do a shutdown(2) on it, but we're the only user
|
|
* anyway, so there's nothing gained.
|
|
*/
|
|
goto out;
|
|
|
|
case MIG_RP_MSG_PONG:
|
|
tmp32 = ldl_be_p(buf);
|
|
trace_source_return_path_thread_pong(tmp32);
|
|
qemu_sem_post(&ms->rp_state.rp_pong_acks);
|
|
break;
|
|
|
|
case MIG_RP_MSG_REQ_PAGES:
|
|
start = ldq_be_p(buf);
|
|
len = ldl_be_p(buf + 8);
|
|
migrate_handle_rp_req_pages(ms, NULL, start, len, &err);
|
|
if (err) {
|
|
goto out;
|
|
}
|
|
break;
|
|
|
|
case MIG_RP_MSG_REQ_PAGES_ID:
|
|
expected_len = 12 + 1; /* header + termination */
|
|
|
|
if (header_len >= expected_len) {
|
|
start = ldq_be_p(buf);
|
|
len = ldl_be_p(buf + 8);
|
|
/* Now we expect an idstr */
|
|
tmp32 = buf[12]; /* Length of the following idstr */
|
|
buf[13 + tmp32] = '\0';
|
|
expected_len += tmp32;
|
|
}
|
|
if (header_len != expected_len) {
|
|
error_setg(&err, "Req_Page_id with length %d expecting %zd",
|
|
header_len, expected_len);
|
|
goto out;
|
|
}
|
|
migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len,
|
|
&err);
|
|
if (err) {
|
|
goto out;
|
|
}
|
|
break;
|
|
|
|
case MIG_RP_MSG_RECV_BITMAP:
|
|
if (header_len < 1) {
|
|
error_setg(&err, "MIG_RP_MSG_RECV_BITMAP missing block name");
|
|
goto out;
|
|
}
|
|
/* Format: len (1B) + idstr (<255B). This ends the idstr. */
|
|
buf[buf[0] + 1] = '\0';
|
|
if (!migrate_handle_rp_recv_bitmap(ms, (char *)(buf + 1), &err)) {
|
|
goto out;
|
|
}
|
|
break;
|
|
|
|
case MIG_RP_MSG_RESUME_ACK:
|
|
tmp32 = ldl_be_p(buf);
|
|
if (!migrate_handle_rp_resume_ack(ms, tmp32, &err)) {
|
|
goto out;
|
|
}
|
|
break;
|
|
|
|
case MIG_RP_MSG_SWITCHOVER_ACK:
|
|
ms->switchover_acked = true;
|
|
trace_source_return_path_thread_switchover_acked();
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (err) {
|
|
migrate_set_error(ms, err);
|
|
error_free(err);
|
|
trace_source_return_path_thread_bad_end();
|
|
}
|
|
|
|
if (ms->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
|
|
/*
|
|
* this will be extremely unlikely: that we got yet another network
|
|
* issue during recovering of the 1st network failure.. during this
|
|
* period the main migration thread can be waiting on rp_sem for
|
|
* this thread to sync with the other side.
|
|
*
|
|
* When this happens, explicitly kick the migration thread out of
|
|
* RECOVER stage and back to PAUSED, so the admin can try
|
|
* everything again.
|
|
*/
|
|
migration_rp_kick(ms);
|
|
}
|
|
|
|
trace_source_return_path_thread_end();
|
|
rcu_unregister_thread();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int open_return_path_on_source(MigrationState *ms)
|
|
{
|
|
ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
|
|
if (!ms->rp_state.from_dst_file) {
|
|
return -1;
|
|
}
|
|
|
|
trace_open_return_path_on_source();
|
|
|
|
qemu_thread_create(&ms->rp_state.rp_thread, "return path",
|
|
source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
|
|
ms->rp_state.rp_thread_created = true;
|
|
|
|
trace_open_return_path_on_source_continue();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return true if error detected, or false otherwise */
|
|
static bool close_return_path_on_source(MigrationState *ms)
|
|
{
|
|
if (!ms->rp_state.rp_thread_created) {
|
|
return false;
|
|
}
|
|
|
|
trace_migration_return_path_end_before();
|
|
|
|
/*
|
|
* If this is a normal exit then the destination will send a SHUT
|
|
* and the rp_thread will exit, however if there's an error we
|
|
* need to cause it to exit. shutdown(2), if we have it, will
|
|
* cause it to unblock if it's stuck waiting for the destination.
|
|
*/
|
|
WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) {
|
|
if (ms->to_dst_file && ms->rp_state.from_dst_file &&
|
|
qemu_file_get_error(ms->to_dst_file)) {
|
|
qemu_file_shutdown(ms->rp_state.from_dst_file);
|
|
}
|
|
}
|
|
|
|
qemu_thread_join(&ms->rp_state.rp_thread);
|
|
ms->rp_state.rp_thread_created = false;
|
|
migration_release_dst_files(ms);
|
|
trace_migration_return_path_end_after();
|
|
|
|
/* Return path will persist the error in MigrationState when quit */
|
|
return migrate_has_error(ms);
|
|
}
|
|
|
|
static inline void
|
|
migration_wait_main_channel(MigrationState *ms)
|
|
{
|
|
/* Wait until one PONG message received */
|
|
qemu_sem_wait(&ms->rp_state.rp_pong_acks);
|
|
}
|
|
|
|
/*
|
|
* Switch from normal iteration to postcopy
|
|
* Returns non-0 on error
|
|
*/
|
|
static int postcopy_start(MigrationState *ms, Error **errp)
|
|
{
|
|
int ret;
|
|
QIOChannelBuffer *bioc;
|
|
QEMUFile *fb;
|
|
uint64_t bandwidth = migrate_max_postcopy_bandwidth();
|
|
bool restart_block = false;
|
|
int cur_state = MIGRATION_STATUS_ACTIVE;
|
|
|
|
if (migrate_postcopy_preempt()) {
|
|
migration_wait_main_channel(ms);
|
|
if (postcopy_preempt_establish_channel(ms)) {
|
|
migrate_set_state(&ms->state, ms->state, MIGRATION_STATUS_FAILED);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (!migrate_pause_before_switchover()) {
|
|
migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
|
|
MIGRATION_STATUS_POSTCOPY_ACTIVE);
|
|
}
|
|
|
|
trace_postcopy_start();
|
|
qemu_mutex_lock_iothread();
|
|
trace_postcopy_start_set_run();
|
|
|
|
migration_downtime_start(ms);
|
|
|
|
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
|
|
global_state_store();
|
|
ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
ret = migration_maybe_pause(ms, &cur_state,
|
|
MIGRATION_STATUS_POSTCOPY_ACTIVE);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
ret = bdrv_inactivate_all();
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
restart_block = true;
|
|
|
|
/*
|
|
* Cause any non-postcopiable, but iterative devices to
|
|
* send out their final data.
|
|
*/
|
|
qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
|
|
|
|
/*
|
|
* in Finish migrate and with the io-lock held everything should
|
|
* be quiet, but we've potentially still got dirty pages and we
|
|
* need to tell the destination to throw any pages it's already received
|
|
* that are dirty
|
|
*/
|
|
if (migrate_postcopy_ram()) {
|
|
ram_postcopy_send_discard_bitmap(ms);
|
|
}
|
|
|
|
/*
|
|
* send rest of state - note things that are doing postcopy
|
|
* will notice we're in POSTCOPY_ACTIVE and not actually
|
|
* wrap their state up here
|
|
*/
|
|
migration_rate_set(bandwidth);
|
|
if (migrate_postcopy_ram()) {
|
|
/* Ping just for debugging, helps line traces up */
|
|
qemu_savevm_send_ping(ms->to_dst_file, 2);
|
|
}
|
|
|
|
/*
|
|
* While loading the device state we may trigger page transfer
|
|
* requests and the fd must be free to process those, and thus
|
|
* the destination must read the whole device state off the fd before
|
|
* it starts processing it. Unfortunately the ad-hoc migration format
|
|
* doesn't allow the destination to know the size to read without fully
|
|
* parsing it through each devices load-state code (especially the open
|
|
* coded devices that use get/put).
|
|
* So we wrap the device state up in a package with a length at the start;
|
|
* to do this we use a qemu_buf to hold the whole of the device state.
|
|
*/
|
|
bioc = qio_channel_buffer_new(4096);
|
|
qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
|
|
fb = qemu_file_new_output(QIO_CHANNEL(bioc));
|
|
object_unref(OBJECT(bioc));
|
|
|
|
/*
|
|
* Make sure the receiver can get incoming pages before we send the rest
|
|
* of the state
|
|
*/
|
|
qemu_savevm_send_postcopy_listen(fb);
|
|
|
|
qemu_savevm_state_complete_precopy(fb, false, false);
|
|
if (migrate_postcopy_ram()) {
|
|
qemu_savevm_send_ping(fb, 3);
|
|
}
|
|
|
|
qemu_savevm_send_postcopy_run(fb);
|
|
|
|
/* <><> end of stuff going into the package */
|
|
|
|
/* Last point of recovery; as soon as we send the package the destination
|
|
* can open devices and potentially start running.
|
|
* Lets just check again we've not got any errors.
|
|
*/
|
|
ret = qemu_file_get_error(ms->to_dst_file);
|
|
if (ret) {
|
|
error_setg(errp, "postcopy_start: Migration stream errored (pre package)");
|
|
goto fail_closefb;
|
|
}
|
|
|
|
restart_block = false;
|
|
|
|
/* Now send that blob */
|
|
if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
|
|
goto fail_closefb;
|
|
}
|
|
qemu_fclose(fb);
|
|
|
|
/* Send a notify to give a chance for anything that needs to happen
|
|
* at the transition to postcopy and after the device state; in particular
|
|
* spice needs to trigger a transition now
|
|
*/
|
|
ms->postcopy_after_devices = true;
|
|
migration_call_notifiers(ms);
|
|
|
|
migration_downtime_end(ms);
|
|
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
if (migrate_postcopy_ram()) {
|
|
/*
|
|
* Although this ping is just for debug, it could potentially be
|
|
* used for getting a better measurement of downtime at the source.
|
|
*/
|
|
qemu_savevm_send_ping(ms->to_dst_file, 4);
|
|
}
|
|
|
|
if (migrate_release_ram()) {
|
|
ram_postcopy_migrated_memory_release(ms);
|
|
}
|
|
|
|
ret = qemu_file_get_error(ms->to_dst_file);
|
|
if (ret) {
|
|
error_setg(errp, "postcopy_start: Migration stream errored");
|
|
migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
|
|
MIGRATION_STATUS_FAILED);
|
|
}
|
|
|
|
trace_postcopy_preempt_enabled(migrate_postcopy_preempt());
|
|
|
|
return ret;
|
|
|
|
fail_closefb:
|
|
qemu_fclose(fb);
|
|
fail:
|
|
migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
|
|
MIGRATION_STATUS_FAILED);
|
|
if (restart_block) {
|
|
/* A failure happened early enough that we know the destination hasn't
|
|
* accessed block devices, so we're safe to recover.
|
|
*/
|
|
Error *local_err = NULL;
|
|
|
|
bdrv_activate_all(&local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
}
|
|
}
|
|
qemu_mutex_unlock_iothread();
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* migration_maybe_pause: Pause if required to by
|
|
* migrate_pause_before_switchover called with the iothread locked
|
|
* Returns: 0 on success
|
|
*/
|
|
static int migration_maybe_pause(MigrationState *s,
|
|
int *current_active_state,
|
|
int new_state)
|
|
{
|
|
if (!migrate_pause_before_switchover()) {
|
|
return 0;
|
|
}
|
|
|
|
/* Since leaving this state is not atomic with posting the semaphore
|
|
* it's possible that someone could have issued multiple migrate_continue
|
|
* and the semaphore is incorrectly positive at this point;
|
|
* the docs say it's undefined to reinit a semaphore that's already
|
|
* init'd, so use timedwait to eat up any existing posts.
|
|
*/
|
|
while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
|
|
/* This block intentionally left blank */
|
|
}
|
|
|
|
/*
|
|
* If the migration is cancelled when it is in the completion phase,
|
|
* the migration state is set to MIGRATION_STATUS_CANCELLING.
|
|
* So we don't need to wait a semaphore, otherwise we would always
|
|
* wait for the 'pause_sem' semaphore.
|
|
*/
|
|
if (s->state != MIGRATION_STATUS_CANCELLING) {
|
|
qemu_mutex_unlock_iothread();
|
|
migrate_set_state(&s->state, *current_active_state,
|
|
MIGRATION_STATUS_PRE_SWITCHOVER);
|
|
qemu_sem_wait(&s->pause_sem);
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
|
|
new_state);
|
|
*current_active_state = new_state;
|
|
qemu_mutex_lock_iothread();
|
|
}
|
|
|
|
return s->state == new_state ? 0 : -EINVAL;
|
|
}
|
|
|
|
static int migration_completion_precopy(MigrationState *s,
|
|
int *current_active_state)
|
|
{
|
|
int ret;
|
|
|
|
qemu_mutex_lock_iothread();
|
|
migration_downtime_start(s);
|
|
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
|
|
|
|
s->vm_old_state = runstate_get();
|
|
global_state_store();
|
|
|
|
ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
|
|
trace_migration_completion_vm_stop(ret);
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = migration_maybe_pause(s, current_active_state,
|
|
MIGRATION_STATUS_DEVICE);
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Inactivate disks except in COLO, and track that we have done so in order
|
|
* to remember to reactivate them if migration fails or is cancelled.
|
|
*/
|
|
s->block_inactive = !migrate_colo();
|
|
migration_rate_set(RATE_LIMIT_DISABLED);
|
|
ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
|
|
s->block_inactive);
|
|
out_unlock:
|
|
qemu_mutex_unlock_iothread();
|
|
return ret;
|
|
}
|
|
|
|
static void migration_completion_postcopy(MigrationState *s)
|
|
{
|
|
trace_migration_completion_postcopy_end();
|
|
|
|
qemu_mutex_lock_iothread();
|
|
qemu_savevm_state_complete_postcopy(s->to_dst_file);
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
/*
|
|
* Shutdown the postcopy fast path thread. This is only needed when dest
|
|
* QEMU binary is old (7.1/7.2). QEMU 8.0+ doesn't need this.
|
|
*/
|
|
if (migrate_postcopy_preempt() && s->preempt_pre_7_2) {
|
|
postcopy_preempt_shutdown_file(s);
|
|
}
|
|
|
|
trace_migration_completion_postcopy_end_after_complete();
|
|
}
|
|
|
|
static void migration_completion_failed(MigrationState *s,
|
|
int current_active_state)
|
|
{
|
|
if (s->block_inactive && (s->state == MIGRATION_STATUS_ACTIVE ||
|
|
s->state == MIGRATION_STATUS_DEVICE)) {
|
|
/*
|
|
* If not doing postcopy, vm_start() will be called: let's
|
|
* regain control on images.
|
|
*/
|
|
Error *local_err = NULL;
|
|
|
|
qemu_mutex_lock_iothread();
|
|
bdrv_activate_all(&local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
} else {
|
|
s->block_inactive = false;
|
|
}
|
|
qemu_mutex_unlock_iothread();
|
|
}
|
|
|
|
migrate_set_state(&s->state, current_active_state,
|
|
MIGRATION_STATUS_FAILED);
|
|
}
|
|
|
|
/**
|
|
* migration_completion: Used by migration_thread when there's not much left.
|
|
* The caller 'breaks' the loop when this returns.
|
|
*
|
|
* @s: Current migration state
|
|
*/
|
|
static void migration_completion(MigrationState *s)
|
|
{
|
|
int ret = 0;
|
|
int current_active_state = s->state;
|
|
|
|
if (s->state == MIGRATION_STATUS_ACTIVE) {
|
|
ret = migration_completion_precopy(s, ¤t_active_state);
|
|
} else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
|
|
migration_completion_postcopy(s);
|
|
} else {
|
|
ret = -1;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
if (close_return_path_on_source(s)) {
|
|
goto fail;
|
|
}
|
|
|
|
if (qemu_file_get_error(s->to_dst_file)) {
|
|
trace_migration_completion_file_err();
|
|
goto fail;
|
|
}
|
|
|
|
if (migrate_colo() && s->state == MIGRATION_STATUS_ACTIVE) {
|
|
/* COLO does not support postcopy */
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
|
|
MIGRATION_STATUS_COLO);
|
|
} else {
|
|
migrate_set_state(&s->state, current_active_state,
|
|
MIGRATION_STATUS_COMPLETED);
|
|
}
|
|
|
|
return;
|
|
|
|
fail:
|
|
migration_completion_failed(s, current_active_state);
|
|
}
|
|
|
|
/**
|
|
* bg_migration_completion: Used by bg_migration_thread when after all the
|
|
* RAM has been saved. The caller 'breaks' the loop when this returns.
|
|
*
|
|
* @s: Current migration state
|
|
*/
|
|
static void bg_migration_completion(MigrationState *s)
|
|
{
|
|
int current_active_state = s->state;
|
|
|
|
if (s->state == MIGRATION_STATUS_ACTIVE) {
|
|
/*
|
|
* By this moment we have RAM content saved into the migration stream.
|
|
* The next step is to flush the non-RAM content (device state)
|
|
* right after the ram content. The device state has been stored into
|
|
* the temporary buffer before RAM saving started.
|
|
*/
|
|
qemu_put_buffer(s->to_dst_file, s->bioc->data, s->bioc->usage);
|
|
qemu_fflush(s->to_dst_file);
|
|
} else if (s->state == MIGRATION_STATUS_CANCELLING) {
|
|
goto fail;
|
|
}
|
|
|
|
if (qemu_file_get_error(s->to_dst_file)) {
|
|
trace_migration_completion_file_err();
|
|
goto fail;
|
|
}
|
|
|
|
migrate_set_state(&s->state, current_active_state,
|
|
MIGRATION_STATUS_COMPLETED);
|
|
return;
|
|
|
|
fail:
|
|
migrate_set_state(&s->state, current_active_state,
|
|
MIGRATION_STATUS_FAILED);
|
|
}
|
|
|
|
typedef enum MigThrError {
|
|
/* No error detected */
|
|
MIG_THR_ERR_NONE = 0,
|
|
/* Detected error, but resumed successfully */
|
|
MIG_THR_ERR_RECOVERED = 1,
|
|
/* Detected fatal error, need to exit */
|
|
MIG_THR_ERR_FATAL = 2,
|
|
} MigThrError;
|
|
|
|
static int postcopy_resume_handshake(MigrationState *s)
|
|
{
|
|
qemu_savevm_send_postcopy_resume(s->to_dst_file);
|
|
|
|
while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
|
|
if (migration_rp_wait(s)) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/* Return zero if success, or <0 for error */
|
|
static int postcopy_do_resume(MigrationState *s)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* Call all the resume_prepare() hooks, so that modules can be
|
|
* ready for the migration resume.
|
|
*/
|
|
ret = qemu_savevm_state_resume_prepare(s);
|
|
if (ret) {
|
|
error_report("%s: resume_prepare() failure detected: %d",
|
|
__func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* If preempt is enabled, re-establish the preempt channel. Note that
|
|
* we do it after resume prepare to make sure the main channel will be
|
|
* created before the preempt channel. E.g. with weak network, the
|
|
* dest QEMU may get messed up with the preempt and main channels on
|
|
* the order of connection setup. This guarantees the correct order.
|
|
*/
|
|
ret = postcopy_preempt_establish_channel(s);
|
|
if (ret) {
|
|
error_report("%s: postcopy_preempt_establish_channel(): %d",
|
|
__func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Last handshake with destination on the resume (destination will
|
|
* switch to postcopy-active afterwards)
|
|
*/
|
|
ret = postcopy_resume_handshake(s);
|
|
if (ret) {
|
|
error_report("%s: handshake failed: %d", __func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We don't return until we are in a safe state to continue current
|
|
* postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
|
|
* MIG_THR_ERR_FATAL if unrecovery failure happened.
|
|
*/
|
|
static MigThrError postcopy_pause(MigrationState *s)
|
|
{
|
|
assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
|
|
|
|
while (true) {
|
|
QEMUFile *file;
|
|
|
|
/*
|
|
* Current channel is possibly broken. Release it. Note that this is
|
|
* guaranteed even without lock because to_dst_file should only be
|
|
* modified by the migration thread. That also guarantees that the
|
|
* unregister of yank is safe too without the lock. It should be safe
|
|
* even to be within the qemu_file_lock, but we didn't do that to avoid
|
|
* taking more mutex (yank_lock) within qemu_file_lock. TL;DR: we make
|
|
* the qemu_file_lock critical section as small as possible.
|
|
*/
|
|
assert(s->to_dst_file);
|
|
migration_ioc_unregister_yank_from_file(s->to_dst_file);
|
|
qemu_mutex_lock(&s->qemu_file_lock);
|
|
file = s->to_dst_file;
|
|
s->to_dst_file = NULL;
|
|
qemu_mutex_unlock(&s->qemu_file_lock);
|
|
|
|
qemu_file_shutdown(file);
|
|
qemu_fclose(file);
|
|
|
|
/*
|
|
* We're already pausing, so ignore any errors on the return
|
|
* path and just wait for the thread to finish. It will be
|
|
* re-created when we resume.
|
|
*/
|
|
close_return_path_on_source(s);
|
|
|
|
migrate_set_state(&s->state, s->state,
|
|
MIGRATION_STATUS_POSTCOPY_PAUSED);
|
|
|
|
error_report("Detected IO failure for postcopy. "
|
|
"Migration paused.");
|
|
|
|
/*
|
|
* We wait until things fixed up. Then someone will setup the
|
|
* status back for us.
|
|
*/
|
|
while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
|
|
qemu_sem_wait(&s->postcopy_pause_sem);
|
|
}
|
|
|
|
if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
|
|
/* Woken up by a recover procedure. Give it a shot */
|
|
|
|
/* Do the resume logic */
|
|
if (postcopy_do_resume(s) == 0) {
|
|
/* Let's continue! */
|
|
trace_postcopy_pause_continued();
|
|
return MIG_THR_ERR_RECOVERED;
|
|
} else {
|
|
/*
|
|
* Something wrong happened during the recovery, let's
|
|
* pause again. Pause is always better than throwing
|
|
* data away.
|
|
*/
|
|
continue;
|
|
}
|
|
} else {
|
|
/* This is not right... Time to quit. */
|
|
return MIG_THR_ERR_FATAL;
|
|
}
|
|
}
|
|
}
|
|
|
|
static MigThrError migration_detect_error(MigrationState *s)
|
|
{
|
|
int ret;
|
|
int state = s->state;
|
|
Error *local_error = NULL;
|
|
|
|
if (state == MIGRATION_STATUS_CANCELLING ||
|
|
state == MIGRATION_STATUS_CANCELLED) {
|
|
/* End the migration, but don't set the state to failed */
|
|
return MIG_THR_ERR_FATAL;
|
|
}
|
|
|
|
/*
|
|
* Try to detect any file errors. Note that postcopy_qemufile_src will
|
|
* be NULL when postcopy preempt is not enabled.
|
|
*/
|
|
ret = qemu_file_get_error_obj_any(s->to_dst_file,
|
|
s->postcopy_qemufile_src,
|
|
&local_error);
|
|
if (!ret) {
|
|
/* Everything is fine */
|
|
assert(!local_error);
|
|
return MIG_THR_ERR_NONE;
|
|
}
|
|
|
|
if (local_error) {
|
|
migrate_set_error(s, local_error);
|
|
error_free(local_error);
|
|
}
|
|
|
|
if (state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret) {
|
|
/*
|
|
* For postcopy, we allow the network to be down for a
|
|
* while. After that, it can be continued by a
|
|
* recovery phase.
|
|
*/
|
|
return postcopy_pause(s);
|
|
} else {
|
|
/*
|
|
* For precopy (or postcopy with error outside IO), we fail
|
|
* with no time.
|
|
*/
|
|
migrate_set_state(&s->state, state, MIGRATION_STATUS_FAILED);
|
|
trace_migration_thread_file_err();
|
|
|
|
/* Time to stop the migration, now. */
|
|
return MIG_THR_ERR_FATAL;
|
|
}
|
|
}
|
|
|
|
static void migration_calculate_complete(MigrationState *s)
|
|
{
|
|
uint64_t bytes = migration_transferred_bytes();
|
|
int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
|
|
int64_t transfer_time;
|
|
|
|
migration_downtime_end(s);
|
|
s->total_time = end_time - s->start_time;
|
|
transfer_time = s->total_time - s->setup_time;
|
|
if (transfer_time) {
|
|
s->mbps = ((double) bytes * 8.0) / transfer_time / 1000;
|
|
}
|
|
}
|
|
|
|
static void update_iteration_initial_status(MigrationState *s)
|
|
{
|
|
/*
|
|
* Update these three fields at the same time to avoid mismatch info lead
|
|
* wrong speed calculation.
|
|
*/
|
|
s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
|
|
s->iteration_initial_bytes = migration_transferred_bytes();
|
|
s->iteration_initial_pages = ram_get_total_transferred_pages();
|
|
}
|
|
|
|
static void migration_update_counters(MigrationState *s,
|
|
int64_t current_time)
|
|
{
|
|
uint64_t transferred, transferred_pages, time_spent;
|
|
uint64_t current_bytes; /* bytes transferred since the beginning */
|
|
uint64_t switchover_bw;
|
|
/* Expected bandwidth when switching over to destination QEMU */
|
|
double expected_bw_per_ms;
|
|
double bandwidth;
|
|
|
|
if (current_time < s->iteration_start_time + BUFFER_DELAY) {
|
|
return;
|
|
}
|
|
|
|
switchover_bw = migrate_avail_switchover_bandwidth();
|
|
current_bytes = migration_transferred_bytes();
|
|
transferred = current_bytes - s->iteration_initial_bytes;
|
|
time_spent = current_time - s->iteration_start_time;
|
|
bandwidth = (double)transferred / time_spent;
|
|
|
|
if (switchover_bw) {
|
|
/*
|
|
* If the user specified a switchover bandwidth, let's trust the
|
|
* user so that can be more accurate than what we estimated.
|
|
*/
|
|
expected_bw_per_ms = switchover_bw / 1000;
|
|
} else {
|
|
/* If the user doesn't specify bandwidth, we use the estimated */
|
|
expected_bw_per_ms = bandwidth;
|
|
}
|
|
|
|
s->threshold_size = expected_bw_per_ms * migrate_downtime_limit();
|
|
|
|
s->mbps = (((double) transferred * 8.0) /
|
|
((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
|
|
|
|
transferred_pages = ram_get_total_transferred_pages() -
|
|
s->iteration_initial_pages;
|
|
s->pages_per_second = (double) transferred_pages /
|
|
(((double) time_spent / 1000.0));
|
|
|
|
/*
|
|
* if we haven't sent anything, we don't want to
|
|
* recalculate. 10000 is a small enough number for our purposes
|
|
*/
|
|
if (stat64_get(&mig_stats.dirty_pages_rate) &&
|
|
transferred > 10000) {
|
|
s->expected_downtime =
|
|
stat64_get(&mig_stats.dirty_bytes_last_sync) / expected_bw_per_ms;
|
|
}
|
|
|
|
migration_rate_reset();
|
|
|
|
update_iteration_initial_status(s);
|
|
|
|
trace_migrate_transferred(transferred, time_spent,
|
|
/* Both in unit bytes/ms */
|
|
bandwidth, switchover_bw / 1000,
|
|
s->threshold_size);
|
|
}
|
|
|
|
static bool migration_can_switchover(MigrationState *s)
|
|
{
|
|
if (!migrate_switchover_ack()) {
|
|
return true;
|
|
}
|
|
|
|
/* No reason to wait for switchover ACK if VM is stopped */
|
|
if (!runstate_is_running()) {
|
|
return true;
|
|
}
|
|
|
|
return s->switchover_acked;
|
|
}
|
|
|
|
/* Migration thread iteration status */
|
|
typedef enum {
|
|
MIG_ITERATE_RESUME, /* Resume current iteration */
|
|
MIG_ITERATE_SKIP, /* Skip current iteration */
|
|
MIG_ITERATE_BREAK, /* Break the loop */
|
|
} MigIterateState;
|
|
|
|
/*
|
|
* Return true if continue to the next iteration directly, false
|
|
* otherwise.
|
|
*/
|
|
static MigIterateState migration_iteration_run(MigrationState *s)
|
|
{
|
|
uint64_t must_precopy, can_postcopy;
|
|
Error *local_err = NULL;
|
|
bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE;
|
|
bool can_switchover = migration_can_switchover(s);
|
|
|
|
qemu_savevm_state_pending_estimate(&must_precopy, &can_postcopy);
|
|
uint64_t pending_size = must_precopy + can_postcopy;
|
|
|
|
trace_migrate_pending_estimate(pending_size, must_precopy, can_postcopy);
|
|
|
|
if (must_precopy <= s->threshold_size) {
|
|
qemu_savevm_state_pending_exact(&must_precopy, &can_postcopy);
|
|
pending_size = must_precopy + can_postcopy;
|
|
trace_migrate_pending_exact(pending_size, must_precopy, can_postcopy);
|
|
}
|
|
|
|
if ((!pending_size || pending_size < s->threshold_size) && can_switchover) {
|
|
trace_migration_thread_low_pending(pending_size);
|
|
migration_completion(s);
|
|
return MIG_ITERATE_BREAK;
|
|
}
|
|
|
|
/* Still a significant amount to transfer */
|
|
if (!in_postcopy && must_precopy <= s->threshold_size && can_switchover &&
|
|
qatomic_read(&s->start_postcopy)) {
|
|
if (postcopy_start(s, &local_err)) {
|
|
migrate_set_error(s, local_err);
|
|
error_report_err(local_err);
|
|
}
|
|
return MIG_ITERATE_SKIP;
|
|
}
|
|
|
|
/* Just another iteration step */
|
|
qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
|
|
return MIG_ITERATE_RESUME;
|
|
}
|
|
|
|
static void migration_iteration_finish(MigrationState *s)
|
|
{
|
|
/* If we enabled cpu throttling for auto-converge, turn it off. */
|
|
cpu_throttle_stop();
|
|
|
|
qemu_mutex_lock_iothread();
|
|
switch (s->state) {
|
|
case MIGRATION_STATUS_COMPLETED:
|
|
migration_calculate_complete(s);
|
|
runstate_set(RUN_STATE_POSTMIGRATE);
|
|
break;
|
|
case MIGRATION_STATUS_COLO:
|
|
assert(migrate_colo());
|
|
migrate_start_colo_process(s);
|
|
s->vm_old_state = RUN_STATE_RUNNING;
|
|
/* Fallthrough */
|
|
case MIGRATION_STATUS_FAILED:
|
|
case MIGRATION_STATUS_CANCELLED:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
if (s->vm_old_state == RUN_STATE_RUNNING) {
|
|
if (!runstate_check(RUN_STATE_SHUTDOWN)) {
|
|
vm_start();
|
|
}
|
|
} else {
|
|
if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
|
|
runstate_set(s->vm_old_state);
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/* Should not reach here, but if so, forgive the VM. */
|
|
error_report("%s: Unknown ending state %d", __func__, s->state);
|
|
break;
|
|
}
|
|
migrate_fd_cleanup_schedule(s);
|
|
qemu_mutex_unlock_iothread();
|
|
}
|
|
|
|
static void bg_migration_iteration_finish(MigrationState *s)
|
|
{
|
|
/*
|
|
* Stop tracking RAM writes - un-protect memory, un-register UFFD
|
|
* memory ranges, flush kernel wait queues and wake up threads
|
|
* waiting for write fault to be resolved.
|
|
*/
|
|
ram_write_tracking_stop();
|
|
|
|
qemu_mutex_lock_iothread();
|
|
switch (s->state) {
|
|
case MIGRATION_STATUS_COMPLETED:
|
|
migration_calculate_complete(s);
|
|
break;
|
|
|
|
case MIGRATION_STATUS_ACTIVE:
|
|
case MIGRATION_STATUS_FAILED:
|
|
case MIGRATION_STATUS_CANCELLED:
|
|
case MIGRATION_STATUS_CANCELLING:
|
|
break;
|
|
|
|
default:
|
|
/* Should not reach here, but if so, forgive the VM. */
|
|
error_report("%s: Unknown ending state %d", __func__, s->state);
|
|
break;
|
|
}
|
|
|
|
migrate_fd_cleanup_schedule(s);
|
|
qemu_mutex_unlock_iothread();
|
|
}
|
|
|
|
/*
|
|
* Return true if continue to the next iteration directly, false
|
|
* otherwise.
|
|
*/
|
|
static MigIterateState bg_migration_iteration_run(MigrationState *s)
|
|
{
|
|
int res;
|
|
|
|
res = qemu_savevm_state_iterate(s->to_dst_file, false);
|
|
if (res > 0) {
|
|
bg_migration_completion(s);
|
|
return MIG_ITERATE_BREAK;
|
|
}
|
|
|
|
return MIG_ITERATE_RESUME;
|
|
}
|
|
|
|
void migration_make_urgent_request(void)
|
|
{
|
|
qemu_sem_post(&migrate_get_current()->rate_limit_sem);
|
|
}
|
|
|
|
void migration_consume_urgent_request(void)
|
|
{
|
|
qemu_sem_wait(&migrate_get_current()->rate_limit_sem);
|
|
}
|
|
|
|
/* Returns true if the rate limiting was broken by an urgent request */
|
|
bool migration_rate_limit(void)
|
|
{
|
|
int64_t now = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
|
|
MigrationState *s = migrate_get_current();
|
|
|
|
bool urgent = false;
|
|
migration_update_counters(s, now);
|
|
if (migration_rate_exceeded(s->to_dst_file)) {
|
|
|
|
if (qemu_file_get_error(s->to_dst_file)) {
|
|
return false;
|
|
}
|
|
/*
|
|
* Wait for a delay to do rate limiting OR
|
|
* something urgent to post the semaphore.
|
|
*/
|
|
int ms = s->iteration_start_time + BUFFER_DELAY - now;
|
|
trace_migration_rate_limit_pre(ms);
|
|
if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) {
|
|
/*
|
|
* We were woken by one or more urgent things but
|
|
* the timedwait will have consumed one of them.
|
|
* The service routine for the urgent wake will dec
|
|
* the semaphore itself for each item it consumes,
|
|
* so add this one we just eat back.
|
|
*/
|
|
qemu_sem_post(&s->rate_limit_sem);
|
|
urgent = true;
|
|
}
|
|
trace_migration_rate_limit_post(urgent);
|
|
}
|
|
return urgent;
|
|
}
|
|
|
|
/*
|
|
* if failover devices are present, wait they are completely
|
|
* unplugged
|
|
*/
|
|
|
|
static void qemu_savevm_wait_unplug(MigrationState *s, int old_state,
|
|
int new_state)
|
|
{
|
|
if (qemu_savevm_state_guest_unplug_pending()) {
|
|
migrate_set_state(&s->state, old_state, MIGRATION_STATUS_WAIT_UNPLUG);
|
|
|
|
while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
|
|
qemu_savevm_state_guest_unplug_pending()) {
|
|
qemu_sem_timedwait(&s->wait_unplug_sem, 250);
|
|
}
|
|
if (s->state != MIGRATION_STATUS_WAIT_UNPLUG) {
|
|
int timeout = 120; /* 30 seconds */
|
|
/*
|
|
* migration has been canceled
|
|
* but as we have started an unplug we must wait the end
|
|
* to be able to plug back the card
|
|
*/
|
|
while (timeout-- && qemu_savevm_state_guest_unplug_pending()) {
|
|
qemu_sem_timedwait(&s->wait_unplug_sem, 250);
|
|
}
|
|
if (qemu_savevm_state_guest_unplug_pending() &&
|
|
!qtest_enabled()) {
|
|
warn_report("migration: partially unplugged device on "
|
|
"failure");
|
|
}
|
|
}
|
|
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG, new_state);
|
|
} else {
|
|
migrate_set_state(&s->state, old_state, new_state);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Master migration thread on the source VM.
|
|
* It drives the migration and pumps the data down the outgoing channel.
|
|
*/
|
|
static void *migration_thread(void *opaque)
|
|
{
|
|
MigrationState *s = opaque;
|
|
MigrationThread *thread = NULL;
|
|
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
|
|
MigThrError thr_error;
|
|
bool urgent = false;
|
|
|
|
thread = migration_threads_add("live_migration", qemu_get_thread_id());
|
|
|
|
rcu_register_thread();
|
|
|
|
object_ref(OBJECT(s));
|
|
update_iteration_initial_status(s);
|
|
|
|
qemu_mutex_lock_iothread();
|
|
qemu_savevm_state_header(s->to_dst_file);
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
/*
|
|
* If we opened the return path, we need to make sure dst has it
|
|
* opened as well.
|
|
*/
|
|
if (s->rp_state.rp_thread_created) {
|
|
/* Now tell the dest that it should open its end so it can reply */
|
|
qemu_savevm_send_open_return_path(s->to_dst_file);
|
|
|
|
/* And do a ping that will make stuff easier to debug */
|
|
qemu_savevm_send_ping(s->to_dst_file, 1);
|
|
}
|
|
|
|
if (migrate_postcopy()) {
|
|
/*
|
|
* Tell the destination that we *might* want to do postcopy later;
|
|
* if the other end can't do postcopy it should fail now, nice and
|
|
* early.
|
|
*/
|
|
qemu_savevm_send_postcopy_advise(s->to_dst_file);
|
|
}
|
|
|
|
if (migrate_colo()) {
|
|
/* Notify migration destination that we enable COLO */
|
|
qemu_savevm_send_colo_enable(s->to_dst_file);
|
|
}
|
|
|
|
qemu_mutex_lock_iothread();
|
|
qemu_savevm_state_setup(s->to_dst_file);
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_ACTIVE);
|
|
|
|
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
|
|
|
|
trace_migration_thread_setup_complete();
|
|
|
|
while (migration_is_active(s)) {
|
|
if (urgent || !migration_rate_exceeded(s->to_dst_file)) {
|
|
MigIterateState iter_state = migration_iteration_run(s);
|
|
if (iter_state == MIG_ITERATE_SKIP) {
|
|
continue;
|
|
} else if (iter_state == MIG_ITERATE_BREAK) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Try to detect any kind of failures, and see whether we
|
|
* should stop the migration now.
|
|
*/
|
|
thr_error = migration_detect_error(s);
|
|
if (thr_error == MIG_THR_ERR_FATAL) {
|
|
/* Stop migration */
|
|
break;
|
|
} else if (thr_error == MIG_THR_ERR_RECOVERED) {
|
|
/*
|
|
* Just recovered from a e.g. network failure, reset all
|
|
* the local variables. This is important to avoid
|
|
* breaking transferred_bytes and bandwidth calculation
|
|
*/
|
|
update_iteration_initial_status(s);
|
|
}
|
|
|
|
urgent = migration_rate_limit();
|
|
}
|
|
|
|
trace_migration_thread_after_loop();
|
|
migration_iteration_finish(s);
|
|
object_unref(OBJECT(s));
|
|
rcu_unregister_thread();
|
|
migration_threads_remove(thread);
|
|
return NULL;
|
|
}
|
|
|
|
static void bg_migration_vm_start_bh(void *opaque)
|
|
{
|
|
MigrationState *s = opaque;
|
|
|
|
qemu_bh_delete(s->vm_start_bh);
|
|
s->vm_start_bh = NULL;
|
|
|
|
vm_start();
|
|
migration_downtime_end(s);
|
|
}
|
|
|
|
/**
|
|
* Background snapshot thread, based on live migration code.
|
|
* This is an alternative implementation of live migration mechanism
|
|
* introduced specifically to support background snapshots.
|
|
*
|
|
* It takes advantage of userfault_fd write protection mechanism introduced
|
|
* in v5.7 kernel. Compared to existing dirty page logging migration much
|
|
* lesser stream traffic is produced resulting in smaller snapshot images,
|
|
* simply cause of no page duplicates can get into the stream.
|
|
*
|
|
* Another key point is that generated vmstate stream reflects machine state
|
|
* 'frozen' at the beginning of snapshot creation compared to dirty page logging
|
|
* mechanism, which effectively results in that saved snapshot is the state of VM
|
|
* at the end of the process.
|
|
*/
|
|
static void *bg_migration_thread(void *opaque)
|
|
{
|
|
MigrationState *s = opaque;
|
|
int64_t setup_start;
|
|
MigThrError thr_error;
|
|
QEMUFile *fb;
|
|
bool early_fail = true;
|
|
|
|
rcu_register_thread();
|
|
object_ref(OBJECT(s));
|
|
|
|
migration_rate_set(RATE_LIMIT_DISABLED);
|
|
|
|
setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
|
|
/*
|
|
* We want to save vmstate for the moment when migration has been
|
|
* initiated but also we want to save RAM content while VM is running.
|
|
* The RAM content should appear first in the vmstate. So, we first
|
|
* stash the non-RAM part of the vmstate to the temporary buffer,
|
|
* then write RAM part of the vmstate to the migration stream
|
|
* with vCPUs running and, finally, write stashed non-RAM part of
|
|
* the vmstate from the buffer to the migration stream.
|
|
*/
|
|
s->bioc = qio_channel_buffer_new(512 * 1024);
|
|
qio_channel_set_name(QIO_CHANNEL(s->bioc), "vmstate-buffer");
|
|
fb = qemu_file_new_output(QIO_CHANNEL(s->bioc));
|
|
object_unref(OBJECT(s->bioc));
|
|
|
|
update_iteration_initial_status(s);
|
|
|
|
/*
|
|
* Prepare for tracking memory writes with UFFD-WP - populate
|
|
* RAM pages before protecting.
|
|
*/
|
|
#ifdef __linux__
|
|
ram_write_tracking_prepare();
|
|
#endif
|
|
|
|
qemu_mutex_lock_iothread();
|
|
qemu_savevm_state_header(s->to_dst_file);
|
|
qemu_savevm_state_setup(s->to_dst_file);
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_ACTIVE);
|
|
|
|
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
|
|
|
|
trace_migration_thread_setup_complete();
|
|
migration_downtime_start(s);
|
|
|
|
qemu_mutex_lock_iothread();
|
|
|
|
/*
|
|
* If VM is currently in suspended state, then, to make a valid runstate
|
|
* transition in vm_stop_force_state() we need to wakeup it up.
|
|
*/
|
|
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
|
|
s->vm_old_state = runstate_get();
|
|
|
|
global_state_store();
|
|
/* Forcibly stop VM before saving state of vCPUs and devices */
|
|
if (migration_stop_vm(RUN_STATE_PAUSED)) {
|
|
goto fail;
|
|
}
|
|
/*
|
|
* Put vCPUs in sync with shadow context structures, then
|
|
* save their state to channel-buffer along with devices.
|
|
*/
|
|
cpu_synchronize_all_states();
|
|
if (qemu_savevm_state_complete_precopy_non_iterable(fb, false, false)) {
|
|
goto fail;
|
|
}
|
|
/*
|
|
* Since we are going to get non-iterable state data directly
|
|
* from s->bioc->data, explicit flush is needed here.
|
|
*/
|
|
qemu_fflush(fb);
|
|
|
|
/* Now initialize UFFD context and start tracking RAM writes */
|
|
if (ram_write_tracking_start()) {
|
|
goto fail;
|
|
}
|
|
early_fail = false;
|
|
|
|
/*
|
|
* Start VM from BH handler to avoid write-fault lock here.
|
|
* UFFD-WP protection for the whole RAM is already enabled so
|
|
* calling VM state change notifiers from vm_start() would initiate
|
|
* writes to virtio VQs memory which is in write-protected region.
|
|
*/
|
|
s->vm_start_bh = qemu_bh_new(bg_migration_vm_start_bh, s);
|
|
qemu_bh_schedule(s->vm_start_bh);
|
|
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
while (migration_is_active(s)) {
|
|
MigIterateState iter_state = bg_migration_iteration_run(s);
|
|
if (iter_state == MIG_ITERATE_SKIP) {
|
|
continue;
|
|
} else if (iter_state == MIG_ITERATE_BREAK) {
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Try to detect any kind of failures, and see whether we
|
|
* should stop the migration now.
|
|
*/
|
|
thr_error = migration_detect_error(s);
|
|
if (thr_error == MIG_THR_ERR_FATAL) {
|
|
/* Stop migration */
|
|
break;
|
|
}
|
|
|
|
migration_update_counters(s, qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
|
|
}
|
|
|
|
trace_migration_thread_after_loop();
|
|
|
|
fail:
|
|
if (early_fail) {
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
|
|
MIGRATION_STATUS_FAILED);
|
|
qemu_mutex_unlock_iothread();
|
|
}
|
|
|
|
bg_migration_iteration_finish(s);
|
|
|
|
qemu_fclose(fb);
|
|
object_unref(OBJECT(s));
|
|
rcu_unregister_thread();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void migrate_fd_connect(MigrationState *s, Error *error_in)
|
|
{
|
|
Error *local_err = NULL;
|
|
uint64_t rate_limit;
|
|
bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
|
|
|
|
/*
|
|
* If there's a previous error, free it and prepare for another one.
|
|
* Meanwhile if migration completes successfully, there won't have an error
|
|
* dumped when calling migrate_fd_cleanup().
|
|
*/
|
|
migrate_error_free(s);
|
|
|
|
s->expected_downtime = migrate_downtime_limit();
|
|
if (resume) {
|
|
assert(s->cleanup_bh);
|
|
} else {
|
|
assert(!s->cleanup_bh);
|
|
s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup_bh, s);
|
|
}
|
|
if (error_in) {
|
|
migrate_fd_error(s, error_in);
|
|
if (resume) {
|
|
/*
|
|
* Don't do cleanup for resume if channel is invalid, but only dump
|
|
* the error. We wait for another channel connect from the user.
|
|
* The error_report still gives HMP user a hint on what failed.
|
|
* It's normally done in migrate_fd_cleanup(), but call it here
|
|
* explicitly.
|
|
*/
|
|
error_report_err(error_copy(s->error));
|
|
} else {
|
|
migrate_fd_cleanup(s);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (resume) {
|
|
/* This is a resumed migration */
|
|
rate_limit = migrate_max_postcopy_bandwidth();
|
|
} else {
|
|
/* This is a fresh new migration */
|
|
rate_limit = migrate_max_bandwidth();
|
|
|
|
/* Notify before starting migration thread */
|
|
migration_call_notifiers(s);
|
|
}
|
|
|
|
migration_rate_set(rate_limit);
|
|
qemu_file_set_blocking(s->to_dst_file, true);
|
|
|
|
/*
|
|
* Open the return path. For postcopy, it is used exclusively. For
|
|
* precopy, only if user specified "return-path" capability would
|
|
* QEMU uses the return path.
|
|
*/
|
|
if (migrate_postcopy_ram() || migrate_return_path()) {
|
|
if (open_return_path_on_source(s)) {
|
|
error_setg(&local_err, "Unable to open return-path for postcopy");
|
|
migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
|
|
migrate_set_error(s, local_err);
|
|
error_report_err(local_err);
|
|
migrate_fd_cleanup(s);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This needs to be done before resuming a postcopy. Note: for newer
|
|
* QEMUs we will delay the channel creation until postcopy_start(), to
|
|
* avoid disorder of channel creations.
|
|
*/
|
|
if (migrate_postcopy_preempt() && s->preempt_pre_7_2) {
|
|
postcopy_preempt_setup(s);
|
|
}
|
|
|
|
if (resume) {
|
|
/* Wakeup the main migration thread to do the recovery */
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
|
|
MIGRATION_STATUS_POSTCOPY_RECOVER);
|
|
qemu_sem_post(&s->postcopy_pause_sem);
|
|
return;
|
|
}
|
|
|
|
if (multifd_save_setup(&local_err) != 0) {
|
|
migrate_set_error(s, local_err);
|
|
error_report_err(local_err);
|
|
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
|
|
MIGRATION_STATUS_FAILED);
|
|
migrate_fd_cleanup(s);
|
|
return;
|
|
}
|
|
|
|
if (migrate_background_snapshot()) {
|
|
qemu_thread_create(&s->thread, "bg_snapshot",
|
|
bg_migration_thread, s, QEMU_THREAD_JOINABLE);
|
|
} else {
|
|
qemu_thread_create(&s->thread, "live_migration",
|
|
migration_thread, s, QEMU_THREAD_JOINABLE);
|
|
}
|
|
s->migration_thread_running = true;
|
|
}
|
|
|
|
static void migration_class_init(ObjectClass *klass, void *data)
|
|
{
|
|
DeviceClass *dc = DEVICE_CLASS(klass);
|
|
|
|
dc->user_creatable = false;
|
|
device_class_set_props(dc, migration_properties);
|
|
}
|
|
|
|
static void migration_instance_finalize(Object *obj)
|
|
{
|
|
MigrationState *ms = MIGRATION_OBJ(obj);
|
|
|
|
qemu_mutex_destroy(&ms->error_mutex);
|
|
qemu_mutex_destroy(&ms->qemu_file_lock);
|
|
qemu_sem_destroy(&ms->wait_unplug_sem);
|
|
qemu_sem_destroy(&ms->rate_limit_sem);
|
|
qemu_sem_destroy(&ms->pause_sem);
|
|
qemu_sem_destroy(&ms->postcopy_pause_sem);
|
|
qemu_sem_destroy(&ms->rp_state.rp_sem);
|
|
qemu_sem_destroy(&ms->rp_state.rp_pong_acks);
|
|
qemu_sem_destroy(&ms->postcopy_qemufile_src_sem);
|
|
error_free(ms->error);
|
|
}
|
|
|
|
static void migration_instance_init(Object *obj)
|
|
{
|
|
MigrationState *ms = MIGRATION_OBJ(obj);
|
|
|
|
ms->state = MIGRATION_STATUS_NONE;
|
|
ms->mbps = -1;
|
|
ms->pages_per_second = -1;
|
|
qemu_sem_init(&ms->pause_sem, 0);
|
|
qemu_mutex_init(&ms->error_mutex);
|
|
|
|
migrate_params_init(&ms->parameters);
|
|
|
|
qemu_sem_init(&ms->postcopy_pause_sem, 0);
|
|
qemu_sem_init(&ms->rp_state.rp_sem, 0);
|
|
qemu_sem_init(&ms->rp_state.rp_pong_acks, 0);
|
|
qemu_sem_init(&ms->rate_limit_sem, 0);
|
|
qemu_sem_init(&ms->wait_unplug_sem, 0);
|
|
qemu_sem_init(&ms->postcopy_qemufile_src_sem, 0);
|
|
qemu_mutex_init(&ms->qemu_file_lock);
|
|
}
|
|
|
|
/*
|
|
* Return true if check pass, false otherwise. Error will be put
|
|
* inside errp if provided.
|
|
*/
|
|
static bool migration_object_check(MigrationState *ms, Error **errp)
|
|
{
|
|
/* Assuming all off */
|
|
bool old_caps[MIGRATION_CAPABILITY__MAX] = { 0 };
|
|
|
|
if (!migrate_params_check(&ms->parameters, errp)) {
|
|
return false;
|
|
}
|
|
|
|
return migrate_caps_check(old_caps, ms->capabilities, errp);
|
|
}
|
|
|
|
static const TypeInfo migration_type = {
|
|
.name = TYPE_MIGRATION,
|
|
/*
|
|
* NOTE: TYPE_MIGRATION is not really a device, as the object is
|
|
* not created using qdev_new(), it is not attached to the qdev
|
|
* device tree, and it is never realized.
|
|
*
|
|
* TODO: Make this TYPE_OBJECT once QOM provides something like
|
|
* TYPE_DEVICE's "-global" properties.
|
|
*/
|
|
.parent = TYPE_DEVICE,
|
|
.class_init = migration_class_init,
|
|
.class_size = sizeof(MigrationClass),
|
|
.instance_size = sizeof(MigrationState),
|
|
.instance_init = migration_instance_init,
|
|
.instance_finalize = migration_instance_finalize,
|
|
};
|
|
|
|
static void register_migration_types(void)
|
|
{
|
|
type_register_static(&migration_type);
|
|
}
|
|
|
|
type_init(register_migration_types);
|