Commit bfbf89c2 authored by Peter Xu's avatar Peter Xu Committed by Juan Quintela
Browse files

migration/qmp: add command migrate-pause 



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: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20180502104740.12123-24-peterx@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>

---
s/2.12/2.13/
parent 62df066f

migration/migration.c

+29 −0
Original line number Diff line number Diff line
@@ -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)) {

qapi/migration.json

+16 −0
Original line number Diff line number Diff line
@@ -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: 2.13

##

{ 'command': 'migrate-pause', 'allow-oob': true }