conf: Forbid device alias change on device-update

https://bugzilla.redhat.com/show_bug.cgi?id=1585108

When updating a live device users might pass different alias than
the one the device has. Currently, this is silently ignored which
goes against our behaviour for other parts of the device where we
explicitly allow only certain changes and error out loudly on
anything else.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

src/conf/domain_conf.c

@@ -28206,7 +28206,8 @@ int
 virDomainDefCompatibleDevice(virDomainDefPtr def,
                              virDomainDeviceDefPtr dev,
                              virDomainDeviceDefPtr oldDev,
-                             virDomainDeviceAction action ATTRIBUTE_UNUSED)
+                             virDomainDeviceAction action,
+                             bool live)
 {
     virDomainCompatibleDeviceData data = {
         .newInfo = virDomainDeviceGetInfo(dev),
@@ -28216,6 +28217,16 @@ virDomainDefCompatibleDevice(virDomainDefPtr def,
     if (oldDev)
         data.oldInfo = virDomainDeviceGetInfo(oldDev);
 
+    if (action == VIR_DOMAIN_DEVICE_ACTION_UPDATE &&
+        live &&
+        ((!!data.newInfo != !!data.oldInfo) ||
+         (data.newInfo && data.oldInfo &&
+          STRNEQ_NULLABLE(data.newInfo->alias, data.oldInfo->alias)))) {
+        virReportError(VIR_ERR_OPERATION_DENIED, "%s",
+                       _("changing device alias is not allowed"));
+        return -1;
+    }
+
     if (!virDomainDefHasUSB(def) &&
         def->os.type != VIR_DOMAIN_OSTYPE_EXE &&
         virDomainDeviceIsUSB(dev)) {

src/conf/domain_conf.h

@@ -3107,7 +3107,8 @@ typedef enum {
 int virDomainDefCompatibleDevice(virDomainDefPtr def,
                                  virDomainDeviceDefPtr dev,
                                  virDomainDeviceDefPtr oldDev,
-                                 virDomainDeviceAction action);
+                                 virDomainDeviceAction action,
+                                 bool live);
 
 void virDomainRNGDefFree(virDomainRNGDefPtr def);
 

src/lxc/lxc_driver.c

@@ -3522,7 +3522,8 @@ lxcDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
 
         oldDev.data.net = vmdef->nets[idx];
         if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev,
-                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                         false) < 0)
             return -1;
 
         virDomainNetDefFree(vmdef->nets[idx]);
@@ -4759,7 +4760,8 @@ static int lxcDomainAttachDeviceFlags(virDomainPtr dom,
             goto endjob;
 
         if (virDomainDefCompatibleDevice(vmdef, dev, NULL,
-                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH,
+                                         false) < 0)
             goto endjob;
 
         if ((ret = lxcDomainAttachDeviceConfig(vmdef, dev)) < 0)
@@ -4768,7 +4770,8 @@ static int lxcDomainAttachDeviceFlags(virDomainPtr dom,
 
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
         if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL,
-                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH,
+                                         true) < 0)
             goto endjob;
 
         if ((ret = lxcDomainAttachDeviceLive(dom->conn, driver, vm, dev_copy)) < 0)

src/qemu/qemu_domain.c

@@ -8643,13 +8643,7 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
         return false;
     }
 
-    if (disk->info.alias &&
-        STRNEQ_NULLABLE(disk->info.alias, orig_disk->info.alias)) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
-                       _("cannot modify field '%s' of the disk"),
-                       "alias");
-        return false;
-    }
+    /* device alias is checked already in virDomainDefCompatibleDevice */
 
     CHECK_EQ(info.bootIndex, "boot order", true);
     CHECK_EQ(rawio, "rawio", true);

src/qemu/qemu_driver.c

@@ -7861,7 +7861,8 @@ qemuDomainChangeDiskLive(virDomainObjPtr vm,
 
     oldDev.data.disk = orig_disk;
     if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev,
-                                     VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                     VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                     true) < 0)
         goto cleanup;
 
     if (!qemuDomainDiskChangeSupported(disk, orig_disk))
@@ -7920,7 +7921,8 @@ qemuDomainUpdateDeviceLive(virDomainObjPtr vm,
         if ((idx = qemuDomainFindGraphicsIndex(vm->def, dev->data.graphics)) >= 0) {
             oldDev.data.graphics = vm->def->graphics[idx];
             if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev,
-                                             VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                             VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                             true) < 0)
                 return -1;
         }
 
@@ -7931,7 +7933,8 @@ qemuDomainUpdateDeviceLive(virDomainObjPtr vm,
         if ((idx = virDomainNetFindIdx(vm->def, dev->data.net)) >= 0) {
             oldDev.data.net = vm->def->nets[idx];
             if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev,
-                                             VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                             VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                             true) < 0)
                 return -1;
         }
 
@@ -8385,7 +8388,8 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
 
         oldDev.data.disk = vmdef->disks[pos];
         if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev,
-                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                         false) < 0)
             return -1;
 
         virDomainDiskDefFree(vmdef->disks[pos]);
@@ -8405,7 +8409,8 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
 
         oldDev.data.graphics = vmdef->graphics[pos];
         if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev,
-                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                         false) < 0)
             return -1;
 
         virDomainGraphicsDefFree(vmdef->graphics[pos]);
@@ -8420,7 +8425,8 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
 
         oldDev.data.net = vmdef->nets[pos];
         if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev,
-                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_UPDATE,
+                                         false) < 0)
             return -1;
 
         virDomainNetDefFree(vmdef->nets[pos]);
@@ -8512,7 +8518,8 @@ qemuDomainAttachDeviceLiveAndConfig(virDomainObjPtr vm,
             goto cleanup;
 
         if (virDomainDefCompatibleDevice(vmdef, dev, NULL,
-                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH,
+                                         false) < 0)
             goto cleanup;
         if ((ret = qemuDomainAttachDeviceConfig(vmdef, dev, caps,
                                                 parse_flags,
@@ -8522,7 +8529,8 @@ qemuDomainAttachDeviceLiveAndConfig(virDomainObjPtr vm,
 
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
         if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL,
-                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH) < 0)
+                                         VIR_DOMAIN_DEVICE_ACTION_ATTACH,
+                                         true) < 0)
             goto cleanup;
 
         if ((ret = qemuDomainAttachDeviceLive(vm, dev_copy, driver)) < 0)

src/qemu/qemu_hotplug.c

@@ -3200,11 +3200,9 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
     if (!newdev->info.alias &&
         VIR_STRDUP(newdev->info.alias, olddev->info.alias) < 0)
         goto cleanup;
-    if (STRNEQ_NULLABLE(olddev->info.alias, newdev->info.alias)) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot modify network device alias"));
-        goto cleanup;
-    }
+
+    /* device alias is checked already in virDomainDefCompatibleDevice */
+
     if (olddev->info.rombar != newdev->info.rombar) {
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
                        _("cannot modify network device rom bar setting"));