block: add block-job-complete

While streaming can be dropped as soon as it progressed through the whole
image, mirroring needs to be completed manually for two reasons: 1) so that
management knows exactly when the VM switches to the target; 2) because
for other use cases such as replication, we may leave the operation running
for the whole life of the virtual machine.

Add a new block job command that manually completes background operations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/blockdev.c b/blockdev.c
index 46e4bbd..02d3e0b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1266,6 +1266,19 @@
     block_job_resume(job);
 }
 
+void qmp_block_job_complete(const char *device, Error **errp)
+{
+    BlockJob *job = find_block_job(device);
+
+    if (!job) {
+        error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
+        return;
+    }
+
+    trace_qmp_block_job_complete(job);
+    block_job_complete(job, errp);
+}
+
 static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
 {
     BlockJobInfoList **prev = opaque;