Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 193 insertions, 0 deletions

diff --git a/job-qmp.c b/job-qmp.c
new file mode 100644
index 000000000..829a28aa7
--- /dev/null
+++ b/job-qmp.c
@@ -0,0 +1,193 @@
+/*
+ * 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/job.h"
+#include "qapi/qapi-commands-job.h"
+#include "qapi/error.h"
+#include "trace/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_ref(job);
+    job_finalize(job, errp);
+
+    /*
+     * Job's context might have changed via job_finalize (and job_txn_apply
+     * automatically acquires the new one), so make sure we release the correct
+     * one.
+     */
+    aio_context = job->aio_context;
+    job_unref(job);
+    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);
+}
+
+static JobInfo *job_query_single(Job *job, Error **errp)
+{
+    JobInfo *info;
+    uint64_t progress_current;
+    uint64_t progress_total;
+
+    assert(!job_is_internal(job));
+    progress_get_snapshot(&job->progress, &progress_current,
+                          &progress_total);
+
+    info = g_new(JobInfo, 1);
+    *info = (JobInfo) {
+        .id                 = g_strdup(job->id),
+        .type               = job_type(job),
+        .status             = job->status,
+        .current_progress   = progress_current,
+        .total_progress     = progress_total,
+        .has_error          = !!job->err,
+        .error              = job->err ? \
+                              g_strdup(error_get_pretty(job->err)) : NULL,
+    };
+
+    return info;
+}
+
+JobInfoList *qmp_query_jobs(Error **errp)
+{
+    JobInfoList *head = NULL, **tail = &head;
+    Job *job;
+
+    for (job = job_next(NULL); job; job = job_next(job)) {
+        JobInfo *value;
+        AioContext *aio_context;
+
+        if (job_is_internal(job)) {
+            continue;
+        }
+        aio_context = job->aio_context;
+        aio_context_acquire(aio_context);
+        value = job_query_single(job, errp);
+        aio_context_release(aio_context);
+        if (!value) {
+            qapi_free_JobInfoList(head);
+            return NULL;
+        }
+        QAPI_LIST_APPEND(tail, value);
+    }
+
+    return head;
+}