[libvirt] [PATCH v3 03/20] qemu: Allow optional export name during NBD export

[Eric Blake]

Right now, we only use NBD exports during storage migration,
where we control the NBD client and therefore don't care about
the export name (qemu's default of naming the export after the
device is fine). But upcoming patches for exposing backups over
NBD wants to use a different export name (matching the libvirt
domain XML rather than the qemu device name); so enhance the
QMP glue code to allow this flexibility.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 src/qemu/qemu_monitor.h      | 1 +
 src/qemu/qemu_monitor_json.h | 1 +
 src/qemu/qemu_migration.c    | 2 +-
 src/qemu/qemu_monitor.c      | 5 +++--
 src/qemu/qemu_monitor_json.c | 2 ++
 tests/qemumonitorjsontest.c  | 2 +-
 6 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 48b142a4f4..b683d0f100 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1074,6 +1074,7 @@ int qemuMonitorNBDServerStart(qemuMonitorPtr mon,
                               const char *tls_alias);
 int qemuMonitorNBDServerAdd(qemuMonitorPtr mon,
                             const char *deviceID,
+                            const char *export,
                             bool writable);
 int qemuMonitorNBDServerStop(qemuMonitorPtr);
 int qemuMonitorGetTPMModels(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index da267b15b0..ac08bc21e0 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -468,6 +468,7 @@ int qemuMonitorJSONNBDServerStart(qemuMonitorPtr mon,
                                   const char *tls_alias);
 int qemuMonitorJSONNBDServerAdd(qemuMonitorPtr mon,
                                 const char *deviceID,
+                                const char *export,
                                 bool writable);
 int qemuMonitorJSONNBDServerStop(qemuMonitorPtr mon);
 int qemuMonitorJSONGetTPMModels(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 67940330aa..5773fa816a 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -417,7 +417,7 @@ qemuMigrationDstStartNBDServer(virQEMUDriverPtr driver,
                 goto exit_monitor;
         }

-        if (qemuMonitorNBDServerAdd(priv->mon, diskAlias, true) < 0)
+        if (qemuMonitorNBDServerAdd(priv->mon, diskAlias, NULL, true) < 0)
             goto exit_monitor;
         if (qemuDomainObjExitMonitor(driver, vm) < 0)
             goto cleanup;
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 7f7013e115..0c2e043fc9 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -3925,13 +3925,14 @@ qemuMonitorNBDServerStart(qemuMonitorPtr mon,
 int
 qemuMonitorNBDServerAdd(qemuMonitorPtr mon,
                         const char *deviceID,
+                        const char *export,
                         bool writable)
 {
-    VIR_DEBUG("deviceID=%s", deviceID);
+    VIR_DEBUG("deviceID=%s, export=%s", deviceID, NULLSTR(export));

     QEMU_CHECK_MONITOR(mon);

-    return qemuMonitorJSONNBDServerAdd(mon, deviceID, writable);
+    return qemuMonitorJSONNBDServerAdd(mon, deviceID, export, writable);
 }


diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 3de298c9e2..29d0395979 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -6727,6 +6727,7 @@ qemuMonitorJSONNBDServerStart(qemuMonitorPtr mon,
 int
 qemuMonitorJSONNBDServerAdd(qemuMonitorPtr mon,
                             const char *deviceID,
+                            const char *export,
                             bool writable)
 {
     int ret = -1;
@@ -6735,6 +6736,7 @@ qemuMonitorJSONNBDServerAdd(qemuMonitorPtr mon,

     if (!(cmd = qemuMonitorJSONMakeCommand("nbd-server-add",
                                            "s:device", deviceID,
+                                           "S:name", export,
                                            "b:writable", writable,
                                            NULL)))
         return ret;
diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c
index 5c77db337f..fa80878196 100644
--- a/tests/qemumonitorjsontest.c
+++ b/tests/qemumonitorjsontest.c
@@ -1353,7 +1353,7 @@ GEN_TEST_FUNC(qemuMonitorJSONDrivePivot, "vdb")
 GEN_TEST_FUNC(qemuMonitorJSONScreendump, "devicename", 1, "/foo/bar")
 GEN_TEST_FUNC(qemuMonitorJSONOpenGraphics, "spice", "spicefd", false)
 GEN_TEST_FUNC(qemuMonitorJSONNBDServerStart, "localhost", 12345, "test-alias")
-GEN_TEST_FUNC(qemuMonitorJSONNBDServerAdd, "vda", true)
+GEN_TEST_FUNC(qemuMonitorJSONNBDServerAdd, "vda", NULL, true)
 GEN_TEST_FUNC(qemuMonitorJSONDetachCharDev, "serial1")
 GEN_TEST_FUNC(qemuMonitorJSONBlockdevTrayOpen, "foodev", true)
 GEN_TEST_FUNC(qemuMonitorJSONBlockdevTrayClose, "foodev")
-- 
2.17.2