[libvirt] [PATCH v1 08/11] qemu_migration: Implement qemuMigrationStartNBDServer()

[Michal Privoznik]

We need to start NBD server and feed it with all non-<shared/> disks.
However, after qemuDomainObjEnterMonitorAsync the domain object
is unlocked so we cannot touch its disk definitions. Therefore,
we must prepare the list of disk IDs prior entering monitor.
---
 src/qemu/qemu_migration.c |   65 +++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 7a2d0a2..3f35a8c 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -33,6 +33,7 @@
 #include "qemu_domain.h"
 #include "qemu_process.h"
 #include "qemu_capabilities.h"
+#include "qemu_command.h"
 #include "qemu_cgroup.h"
 
 #include "domain_audit.h"
@@ -1099,12 +1100,66 @@ qemuMigrationNextPort(void) {
  * Returns 0 on success, -1 otherwise.
  */
 static int
-qemuMigrationStartNBDServer(struct qemud_driver *driver ATTRIBUTE_UNUSED,
-                            virDomainObjPtr vm ATTRIBUTE_UNUSED,
-                            int *nbdPort ATTRIBUTE_UNUSED)
+qemuMigrationStartNBDServer(struct qemud_driver *driver,
+                            virDomainObjPtr vm,
+                            int *nbdPort)
 {
-    /* do nothing for now */
-    return 0;
+    int ret = -1;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    int port = qemuMigrationNextPort();
+    const char *listen = "0.0.0.0";
+    char **disks = NULL;
+    size_t i, ndisks = 0;
+
+    for (i = 0; i < vm->def->ndisks; i++) {
+        virDomainDiskDefPtr disk = vm->def->disks[i];
+
+        /* skip shared disks */
+        if (disk->shared)
+            continue;
+
+        if (VIR_REALLOC_N(disks, ndisks + 1) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
+
+        if (virAsprintf(&disks[ndisks++], "%s%s",
+                        QEMU_DRIVE_HOST_PREFIX, disk->info.alias) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
+    }
+
+    if (!ndisks) {
+        /* Hooray! Nothing to care about */
+        ret = 0;
+        goto cleanup;
+    }
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm,
+                                       QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
+        goto cleanup;
+
+    if (qemuMonitorNBDServerStart(priv->mon, listen, port) < 0)
+        goto endjob;
+
+    for (i = 0; i < ndisks; i++) {
+        if (qemuMonitorNBDServerAdd(priv->mon, disks[i]) < 0) {
+            VIR_WARN("Unable to add '%s' to NDB server", disks[i]);
+            goto endjob;
+        }
+    }
+
+    *nbdPort = port;
+    ret = 0;
+
+endjob:
+    qemuDomainObjExitMonitorWithDriver(driver, vm);
+cleanup:
+    for (i = 0; i < ndisks; i++)
+        VIR_FREE(disks[i]);
+    VIR_FREE(disks);
+    return ret;
 }
 
 
-- 
1.7.8.6