qemu: Move <rng> validation out of qemu_command.c

Move the rng->model == VIRTIO check to parse time. This also
allows us to remove similar checks throughout the qemu driver

Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>

src/qemu/qemu_command.c

@@ -5871,14 +5871,6 @@ qemuBuildRNGDevStr(const virDomainDef *def,
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
 
-    if (dev->model != VIR_DOMAIN_RNG_MODEL_VIRTIO ||
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIRTIO_RNG)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                       _("this qemu doesn't support RNG device type '%s'"),
-                       virDomainRNGModelTypeToString(dev->model));
-        goto error;
-    }
-
     if (!qemuDomainCheckCCWS390AddressSupport(def, dev->info, qemuCaps,
                                               dev->source.file))
         goto error;

src/qemu/qemu_domain.c

@@ -4536,12 +4536,31 @@ qemuDomainSmartcardDefValidate(const virDomainSmartcardDef *def)
 
 
 static int
-qemuDomainRNGDefValidate(const virDomainRNGDef *def)
+qemuDomainRNGDefValidate(const virDomainRNGDef *def,
+                         virQEMUCapsPtr qemuCaps)
 {
+    bool modelIsSupported = false;
+
     if (def->backend == VIR_DOMAIN_RNG_BACKEND_EGD &&
         qemuDomainChrSourceDefValidate(def->source.chardev) < 0)
         return -1;
 
+    switch ((virDomainRNGModel) def->model) {
+    case VIR_DOMAIN_RNG_MODEL_VIRTIO:
+        modelIsSupported = virQEMUCapsGet(qemuCaps,
+                                          QEMU_CAPS_DEVICE_VIRTIO_RNG);
+        break;
+    case VIR_DOMAIN_RNG_MODEL_LAST:
+        break;
+    }
+
+    if (!modelIsSupported) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("this qemu doesn't support RNG device type '%s'"),
+                       virDomainRNGModelTypeToString(def->model));
+        return -1;
+    }
+
     return 0;
 }
 
@@ -6073,7 +6092,7 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
         break;
 
     case VIR_DOMAIN_DEVICE_RNG:
-        ret = qemuDomainRNGDefValidate(dev->data.rng);
+        ret = qemuDomainRNGDefValidate(dev->data.rng, qemuCaps);
         break;
 
     case VIR_DOMAIN_DEVICE_REDIRDEV:

src/qemu/qemu_domain_address.c

@@ -364,8 +364,8 @@ qemuDomainPrimeVirtioDeviceAddresses(virDomainDefPtr def,
         def->memballoon->info.type = type;
 
     for (i = 0; i < def->nrngs; i++) {
-        if (def->rngs[i]->model == VIR_DOMAIN_RNG_MODEL_VIRTIO &&
+        /* All <rng> devices accepted by the qemu driver are virtio */
-            def->rngs[i]->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
+        if (def->rngs[i]->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
             def->rngs[i]->info.type = type;
     }
 
@@ -2276,10 +2276,9 @@ qemuDomainAssignDevicePCISlots(virDomainDefPtr def,
             goto error;
     }
 
-    /* VirtIO RNG */
+    /* the qemu driver only accepts virtio rng devices */
     for (i = 0; i < def->nrngs; i++) {
-        if (def->rngs[i]->model != VIR_DOMAIN_RNG_MODEL_VIRTIO ||
+        if (!virDeviceInfoPCIAddressIsWanted(&def->rngs[i]->info))
-            !virDeviceInfoPCIAddressIsWanted(&def->rngs[i]->info))
             continue;
 
         if (qemuDomainPCIAddressReserveNextAddr(addrs, &def->rngs[i]->info) < 0)

tests/qemuxml2xmltest.c

@@ -585,8 +585,10 @@ mymain(void)
 
     DO_TEST("disk-serial", NONE);
 
-    DO_TEST("virtio-rng-random", NONE);
+    DO_TEST("virtio-rng-random",
-    DO_TEST("virtio-rng-egd", NONE);
+            QEMU_CAPS_DEVICE_VIRTIO_RNG);
+    DO_TEST("virtio-rng-egd",
+            QEMU_CAPS_DEVICE_VIRTIO_RNG);
 
     DO_TEST("pseries-nvram",
             QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE);
@@ -1019,7 +1021,8 @@ mymain(void)
     DO_TEST("disk-backing-chains-index", NONE);
     DO_TEST("disk-backing-chains-noindex", NONE);
 
-    DO_TEST("chardev-label", NONE);
+    DO_TEST("chardev-label",
+            QEMU_CAPS_DEVICE_VIRTIO_RNG);
 
     DO_TEST("cpu-numa1", NONE);
     DO_TEST("cpu-numa2", NONE);