qemu: Add helper to assign RNG device aliases

This function is used to assign an alias for a RNG device. It will be
later reused when hotplugging RNGs.
Signed-off-by: NLuyao Huang <lhuang@redhat.com>
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>

src/qemu/qemu_command.c

@@ -1030,6 +1030,17 @@ qemuGetNextChrDevIndex(virDomainDefPtr def,
 }
 
 
+int
+qemuAssignDeviceRNGAlias(virDomainRNGDefPtr rng,
+                         size_t idx)
+{
+    if (virAsprintf(&rng->info.alias, "rng%zu", idx) < 0)
+        return -1;
+
+    return 0;
+}
+
+
 int
 qemuAssignDeviceChrAlias(virDomainDefPtr def,
                          virDomainChrDefPtr chr,
@@ -1155,7 +1166,7 @@ qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps)
             return -1;
     }
     for (i = 0; i < def->nrngs; i++) {
-        if (virAsprintf(&def->rngs[i]->info.alias, "rng%zu", i) < 0)
+        if (qemuAssignDeviceRNGAlias(def->rngs[i], i) < 0)
             return -1;
     }
     if (def->tpm) {

src/qemu/qemu_command.h

@@ -269,6 +269,7 @@ int qemuAssignDeviceRedirdevAlias(virDomainDefPtr def, virDomainRedirdevDefPtr r
 int qemuAssignDeviceChrAlias(virDomainDefPtr def,
                              virDomainChrDefPtr chr,
                              ssize_t idx);
+int qemuAssignDeviceRNGAlias(virDomainRNGDefPtr rng, size_t idx);
 
 int
 qemuParseKeywords(const char *str,