[libvirt] [PATCH 2/6] Make state driver device hotplug/update actually transient

[Cole Robinson]

The current semantics of non-persistent hotplug/update are confusing: the
changes will persist as long as the in memory domain definition isn't
overwritten. This means hotplug changes stay around until the domain is
redefined or libvirtd is restarted.

Call virDomainObjSetDefTransient at VM startup, so that we properly discard
hotplug changes when the VM is shutdown.

Signed-off-by: Cole Robinson <crobinso at redhat.com>
---
 src/lxc/lxc_driver.c   |    3 +++
 src/qemu/qemu_driver.c |    5 +++++
 src/test/test_driver.c |   42 ++++++++++++++++++++++++------------------
 src/uml/uml_driver.c   |    5 ++++-
 4 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index f5014cb..f6ba137 100644
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -1532,6 +1532,9 @@ static int lxcVmStart(virConnectPtr conn,
     if (virDomainSaveConfig(driver->stateDir, vm->def) < 0)
         goto cleanup;
 
+    if (virDomainObjSetDefTransient(driver->caps, vm) < 0)
+        goto cleanup;
+
     rc = 0;
 
 cleanup:
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ed1ea6b..18b3f16 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4235,6 +4235,11 @@ static int qemudStartVMDaemon(virConnectPtr conn,
     if (virDomainSaveStatus(driver->caps, driver->stateDir, vm) < 0)
         goto cleanup;
 
+    /* Do this last, since it depends on domain being active */
+    DEBUG0("Setting running domain def as transient");
+    if (virDomainObjSetDefTransient(driver->caps, vm) < 0)
+        goto cleanup;
+
     VIR_FORCE_CLOSE(logfile);
 
     return 0;
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index 5693d7a..5e737e8 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -457,6 +457,22 @@ cleanup:
     return ret;
 }
 
+static void
+testDomainShutdownState(virDomainPtr domain,
+                        virDomainObjPtr privdom)
+{
+    if (privdom->newDef) {
+        virDomainDefFree(privdom->def);
+        privdom->def = privdom->newDef;
+        privdom->newDef = NULL;
+    }
+
+    privdom->state = VIR_DOMAIN_SHUTOFF;
+    privdom->def->id = -1;
+    if (domain)
+        domain->id = -1;
+}
+
 /* Set up domain runtime state */
 static int
 testDomainStartState(virConnectPtr conn,
@@ -468,30 +484,20 @@ testDomainStartState(virConnectPtr conn,
     if (testDomainUpdateVCPUs(conn, dom, dom->def->vcpus, 1) < 0)
         goto cleanup;
 
-    /* Set typical run state */
     dom->state = VIR_DOMAIN_RUNNING;
     dom->def->id = privconn->nextDomID++;
 
+    if (virDomainObjSetDefTransient(privconn->caps, dom) < 0) {
+        goto cleanup;
+    }
+
     ret = 0;
 cleanup:
+    if (ret < 0)
+        testDomainShutdownState(NULL, dom);
     return ret;
 }
 
-static void
-testDomainShutdownState(virDomainPtr domain,
-                        virDomainObjPtr privdom)
-{
-    if (privdom->newDef) {
-        virDomainDefFree(privdom->def);
-        privdom->def = privdom->newDef;
-        privdom->newDef = NULL;
-    }
-
-    privdom->state = VIR_DOMAIN_SHUTOFF;
-    privdom->def->id = -1;
-    domain->id = -1;
-}
-
 static int testOpenDefault(virConnectPtr conn) {
     int u;
     struct timeval tv;
@@ -558,12 +564,12 @@ static int testOpenDefault(virConnectPtr conn) {
         goto error;
     domdef = NULL;
 
+    domobj->persistent = 1;
     if (testDomainStartState(conn, domobj) < 0) {
         virDomainObjUnlock(domobj);
         goto error;
     }
 
-    domobj->persistent = 1;
     virDomainObjUnlock(domobj);
 
     if (!(netdef = virNetworkDefParseString(defaultNetworkXML)))
@@ -918,12 +924,12 @@ static int testOpenFromFile(virConnectPtr conn,
             goto error;
         }
 
+        dom->persistent = 1;
         if (testDomainStartState(conn, dom) < 0) {
             virDomainObjUnlock(dom);
             goto error;
         }
 
-        dom->persistent = 1;
         virDomainObjUnlock(dom);
     }
     VIR_FREE(domains);
diff --git a/src/uml/uml_driver.c b/src/uml/uml_driver.c
index ca4e7be..eaa3509 100644
--- a/src/uml/uml_driver.c
+++ b/src/uml/uml_driver.c
@@ -916,7 +916,11 @@ static int umlStartVMDaemon(virConnectPtr conn,
                            VIR_EXEC_CLEAR_CAPS,
                            NULL, NULL, NULL);
     VIR_FORCE_CLOSE(logfd);
+    if (ret < 0)
+        goto cleanup;
 
+    ret = virDomainObjSetDefTransient(driver->caps, vm);
+cleanup:
     /*
      * At the moment, the only thing that populates keepfd is
      * umlBuildCommandLineChr. We want to close every fd it opens.
@@ -940,7 +944,6 @@ static int umlStartVMDaemon(virConnectPtr conn,
         umlCleanupTapDevices(conn, vm);
     }
 
-
     /* NB we don't mark it running here - we do that async
        with inotify */
     /* XXX what if someone else tries to start it again
-- 
1.7.3.2