[libvirt] [PATCH 2/2] conf: Forbid device alias change on device-update

[Michal Privoznik]

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: Michal Privoznik <mprivozn at redhat.com>
---
 src/conf/domain_conf.c | 12 +++++++++++-
 src/conf/domain_conf.h |  3 ++-
 src/lxc/lxc_driver.c   |  6 +++---
 src/qemu/qemu_driver.c | 16 ++++++++--------
 4 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 85f07af46e..91cac75c0a 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -28195,7 +28195,8 @@ virDomainDeviceInfoCheckBootIndex(virDomainDefPtr def ATTRIBUTE_UNUSED,
 int
 virDomainDefCompatibleDevice(virDomainDefPtr def,
                              virDomainDeviceDefPtr dev,
-                             virDomainDeviceDefPtr oldDev)
+                             virDomainDeviceDefPtr oldDev,
+                             bool live)
 {
     virDomainCompatibleDeviceData data = {
         .newInfo = virDomainDeviceGetInfo(dev),
@@ -28205,6 +28206,15 @@ virDomainDefCompatibleDevice(virDomainDefPtr def,
     if (oldDev)
         data.oldInfo = virDomainDeviceGetInfo(oldDev);
 
+    if (live &&
+        ((!!data.newInfo != !!data.oldInfo) ||
+         (data.newInfo && data.oldInfo &&
+          STRNEQ(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)) {
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index ea8ddb2b39..c03028efb9 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -3107,7 +3107,8 @@ typedef enum {
 
 int virDomainDefCompatibleDevice(virDomainDefPtr def,
                                  virDomainDeviceDefPtr dev,
-                                 virDomainDeviceDefPtr oldDev);
+                                 virDomainDeviceDefPtr oldDev,
+                                 bool live);
 
 void virDomainRNGDefFree(virDomainRNGDefPtr def);
 
diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index cfb431488d..fb7c8135e0 100644
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -3549,7 +3549,7 @@ lxcDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
             goto cleanup;
 
         oldDev.data.net = vmdef->nets[idx];
-        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev, false) < 0)
             return -1;
 
         virDomainNetDefFree(vmdef->nets[idx]);
@@ -4785,7 +4785,7 @@ static int lxcDomainAttachDeviceFlags(virDomainPtr dom,
         if (!vmdef)
             goto endjob;
 
-        if (virDomainDefCompatibleDevice(vmdef, dev, NULL) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, NULL, false) < 0)
             goto endjob;
 
         if ((ret = lxcDomainAttachDeviceConfig(vmdef, dev)) < 0)
@@ -4793,7 +4793,7 @@ static int lxcDomainAttachDeviceFlags(virDomainPtr dom,
     }
 
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
-        if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL) < 0)
+        if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL, true) < 0)
             goto endjob;
 
         if ((ret = lxcDomainAttachDeviceLive(dom->conn, driver, vm, dev_copy)) < 0)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ab5cc6ea31..2d4e777b47 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -7860,7 +7860,7 @@ qemuDomainChangeDiskLive(virDomainObjPtr vm,
     }
 
     oldDev.data.disk = orig_disk;
-    if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev) < 0)
+    if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev, true) < 0)
         goto cleanup;
 
     if (!qemuDomainDiskChangeSupported(disk, orig_disk))
@@ -7918,7 +7918,7 @@ qemuDomainUpdateDeviceLive(virDomainObjPtr vm,
     case VIR_DOMAIN_DEVICE_GRAPHICS:
         if ((idx = qemuDomainFindGraphicsIndex(vm->def, dev->data.graphics)) >= 0) {
             oldDev.data.graphics = vm->def->graphics[idx];
-            if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev) < 0)
+            if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev, true) < 0)
                 return -1;
         }
 
@@ -7928,7 +7928,7 @@ qemuDomainUpdateDeviceLive(virDomainObjPtr vm,
     case VIR_DOMAIN_DEVICE_NET:
         if ((idx = virDomainNetFindIdx(vm->def, dev->data.net)) >= 0) {
             oldDev.data.net = vm->def->nets[idx];
-            if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev) < 0)
+            if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev, true) < 0)
                 return -1;
         }
 
@@ -8383,7 +8383,7 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
         }
 
         oldDev.data.disk = vmdef->disks[pos];
-        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev, false) < 0)
             return -1;
 
         virDomainDiskDefFree(vmdef->disks[pos]);
@@ -8402,7 +8402,7 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
         }
 
         oldDev.data.graphics = vmdef->graphics[pos];
-        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev, false) < 0)
             return -1;
 
         virDomainGraphicsDefFree(vmdef->graphics[pos]);
@@ -8416,7 +8416,7 @@ qemuDomainUpdateDeviceConfig(virDomainDefPtr vmdef,
             return -1;
 
         oldDev.data.net = vmdef->nets[pos];
-        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, &oldDev, false) < 0)
             return -1;
 
         virDomainNetDefFree(vmdef->nets[pos]);
@@ -8507,7 +8507,7 @@ qemuDomainAttachDeviceLiveAndConfig(virDomainObjPtr vm,
         if (!vmdef)
             goto cleanup;
 
-        if (virDomainDefCompatibleDevice(vmdef, dev, NULL) < 0)
+        if (virDomainDefCompatibleDevice(vmdef, dev, NULL, false) < 0)
             goto cleanup;
         if ((ret = qemuDomainAttachDeviceConfig(vmdef, dev, caps,
                                                 parse_flags,
@@ -8516,7 +8516,7 @@ qemuDomainAttachDeviceLiveAndConfig(virDomainObjPtr vm,
     }
 
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
-        if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL) < 0)
+        if (virDomainDefCompatibleDevice(vm->def, dev_copy, NULL, true) < 0)
             goto cleanup;
 
         if ((ret = qemuDomainAttachDeviceLive(vm, dev_copy, driver)) < 0)
-- 
2.16.4