diff mbox series

[PULL,36/41] migration/qmp: add command migrate-pause

Message ID 20180509112406.6183-37-quintela@redhat.com
State New
Headers show
Series [PULL,01/41] migration: fix saving normal page even if it's been compressed | expand

Commit Message

Juan Quintela May 9, 2018, 11:24 a.m. UTC 
From: Peter Xu <peterx@redhat.com>

It pauses an ongoing migration.  Currently it only supports postcopy.
Note that this command will work on either side of the migration.
Basically when we trigger this on one side, it'll interrupt the other
side as well since the other side will get notified on the disconnect
event.

However, it's still possible that the other side is not notified, for
example, when the network is totally broken, or due to some firewall
configuration changes.  In that case, we will also need to run the same
command on the other side so both sides will go into the paused state.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180502104740.12123-24-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/migration.c | 29 +++++++++++++++++++++++++++++
 qapi/migration.json   | 16 ++++++++++++++++
 2 files changed, 45 insertions(+)

Comments

Eric Blake May 9, 2018, 12:59 p.m. UTC | #1 
On 05/09/2018 06:24 AM, Juan Quintela wrote:
> From: Peter Xu <peterx@redhat.com>
> 
> It pauses an ongoing migration.  Currently it only supports postcopy.
> Note that this command will work on either side of the migration.
> Basically when we trigger this on one side, it'll interrupt the other
> side as well since the other side will get notified on the disconnect
> event.
> 
> However, it's still possible that the other side is not notified, for
> example, when the network is totally broken, or due to some firewall
> configuration changes.  In that case, we will also need to run the same
> command on the other side so both sides will go into the paused state.
> 

> +++ b/qapi/migration.json
> @@ -1211,3 +1211,19 @@
>   ##
>   { 'command': 'migrate-recover', 'data': { 'uri': 'str' },
>     'allow-oob': true }
> +
> +##
> +# @migrate-pause:
> +#
> +# Pause a migration.  Currently it only supports postcopy.
> +#
> +# Returns: nothing.
> +#
> +# Example:
> +#
> +# -> { "execute": "migrate-pause" }
> +# <- { "return": {} }
> +#
> +# Since: 2.12

Another 2.13 fixup

> +##
> +{ 'command': 'migrate-pause', 'allow-oob': true }
>
diff mbox series

Patch

diff --git a/migration/migration.c b/migration/migration.c
index 3deded90e5..05aec2c905 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1507,6 +1507,35 @@  void qmp_migrate_recover(const char *uri, Error **errp)
     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;
+
+    if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
+        /* Source side, during postcopy */
+        qemu_mutex_lock(&ms->qemu_file_lock);
+        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");
+        }
+        return;
+    }
+
+    if (mis->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
+        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 state");
+}
+
 bool migration_is_blocked(Error **errp)
 {
     if (qemu_savevm_state_blocked(errp)) {
diff --git a/qapi/migration.json b/qapi/migration.json
index ec739cbd04..7e9283c613 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1211,3 +1211,19 @@ 
 ##
 { 'command': 'migrate-recover', 'data': { 'uri': 'str' },
   'allow-oob': true }
+
+##
+# @migrate-pause:
+#
+# Pause a migration.  Currently it only supports postcopy.
+#
+# Returns: nothing.
+#
+# Example:
+#
+# -> { "execute": "migrate-pause" }
+# <- { "return": {} }
+#
+# Since: 2.12
+##
+{ 'command': 'migrate-pause', 'allow-oob': true }