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[Qemu-devel] [RFC 28/29] migration: final handshake for the resume
From: |
Peter Xu |
Subject: |
[Qemu-devel] [RFC 28/29] migration: final handshake for the resume |
Date: |
Fri, 28 Jul 2017 16:06:37 +0800 |
Finish the last step to do the final handshake for the recovery.
First source sends one MIG_CMD_RESUME to dst, telling that source is
ready to resume.
Then, dest replies with MIG_RP_MSG_RESUME_ACK to source, telling that
dest is ready to resume (after switch to postcopy-active state).
When source received the RESUME_ACK, it switches its state to
postcopy-active, and finally the recovery is completed.
Signed-off-by: Peter Xu <address@hidden>
---
migration/migration.c | 39 +++++++++++++++++++++++++++++++++++----
1 file changed, 35 insertions(+), 4 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 93fbc96..ecebe30 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1666,6 +1666,13 @@ static int migrate_handle_rp_recv_bitmap(MigrationState
*s, char *block_name)
return ram_dirty_bitmap_reload(s, block);
}
+static void postcopy_resume_handshake_ack(MigrationState *s)
+{
+ qemu_mutex_lock(&s->resume_lock);
+ qemu_cond_signal(&s->resume_cond);
+ qemu_mutex_unlock(&s->resume_lock);
+}
+
static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value)
{
trace_source_return_path_thread_resume_ack(value);
@@ -1680,7 +1687,8 @@ static int migrate_handle_rp_resume_ack(MigrationState
*s, uint32_t value)
migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
MIGRATION_STATUS_POSTCOPY_ACTIVE);
- /* TODO: notify send thread that time to continue send pages */
+ /* Notify send thread that time to continue send pages */
+ postcopy_resume_handshake_ack(s);
return 0;
}
@@ -2151,6 +2159,25 @@ static bool postcopy_should_start(MigrationState *s)
return atomic_read(&s->start_postcopy) || s->start_postcopy_fast;
}
+static int postcopy_resume_handshake(MigrationState *s)
+{
+ qemu_mutex_lock(&s->resume_lock);
+
+ qemu_savevm_send_postcopy_resume(s->to_dst_file);
+
+ while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
+ qemu_cond_wait(&s->resume_cond, &s->resume_lock);
+ }
+
+ qemu_mutex_unlock(&s->resume_lock);
+
+ 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)
{
@@ -2168,10 +2195,14 @@ static int postcopy_do_resume(MigrationState *s)
}
/*
- * TODO: handshake with dest using MIG_CMD_RESUME,
- * MIG_RP_MSG_RESUME_ACK, then switch source state to
- * "postcopy-active"
+ * 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;
}
--
2.7.4
- [Qemu-devel] [RFC 19/29] migration: let dst listen on port always, (continued)
- [Qemu-devel] [RFC 19/29] migration: let dst listen on port always, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 18/29] migration: new state "postcopy-recover", Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 20/29] migration: wakeup dst ram-load-thread for recover, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 21/29] migration: new cmd MIG_CMD_RECV_BITMAP, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 22/29] migration: new message MIG_RP_MSG_RECV_BITMAP, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 23/29] migration: new cmd MIG_CMD_POSTCOPY_RESUME, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 24/29] migration: new message MIG_RP_MSG_RESUME_ACK, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 25/29] migration: introduce SaveVMHandlers.resume_prepare, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 26/29] migration: synchronize dirty bitmap for resume, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 27/29] migration: setup ramstate for resume, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 28/29] migration: final handshake for the resume,
Peter Xu <=
- [Qemu-devel] [RFC 29/29] migration: reset migrate thread vars when resumed, Peter Xu, 2017/07/28
- Re: [Qemu-devel] [RFC 00/29] Migration: postcopy failure recovery, Peter Xu, 2017/07/28