job: Add lifecycle QMP commands

This adds QMP commands that control the transition between states of the
job lifecycle.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

job-qmp.c

@@ -0,0 +1,134 @@
+/*
+ * QMP interface for background jobs
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012, 2018 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/job.h"
+#include "qapi/qapi-commands-job.h"
+#include "qapi/error.h"
+#include "trace-root.h"
+
+/* Get a job using its ID and acquire its AioContext */
+static Job *find_job(const char *id, AioContext **aio_context, Error **errp)
+{
+    Job *job;
+
+    *aio_context = NULL;
+
+    job = job_get(id);
+    if (!job) {
+        error_setg(errp, "Job not found");
+        return NULL;
+    }
+
+    *aio_context = job->aio_context;
+    aio_context_acquire(*aio_context);
+
+    return job;
+}
+
+void qmp_job_cancel(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_cancel(job);
+    job_user_cancel(job, true, errp);
+    aio_context_release(aio_context);
+}
+
+void qmp_job_pause(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_pause(job);
+    job_user_pause(job, errp);
+    aio_context_release(aio_context);
+}
+
+void qmp_job_resume(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_resume(job);
+    job_user_resume(job, errp);
+    aio_context_release(aio_context);
+}
+
+void qmp_job_complete(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_complete(job);
+    job_complete(job, errp);
+    aio_context_release(aio_context);
+}
+
+void qmp_job_finalize(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_finalize(job);
+    job_finalize(job, errp);
+    aio_context_release(aio_context);
+}
+
+void qmp_job_dismiss(const char *id, Error **errp)
+{
+    AioContext *aio_context;
+    Job *job = find_job(id, &aio_context, errp);
+
+    if (!job) {
+        return;
+    }
+
+    trace_qmp_job_dismiss(job);
+    job_dismiss(&job, errp);
+    aio_context_release(aio_context);
+}