qemuMonitorJSONAttachCharDev: Teach spicevmc

https://bugzilla.redhat.com/show_bug.cgi?id=1298070

We have the code for attaching redirdevs for ages now.
Unfortunately, our monitor code that handles talking to the qemu
process was missing a little piece of code that actually enabled
the feature.

BTW: it really is called "type" on the monitor, even though it's
called "name" on the cmd line. Don't ask.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_monitor_json.c

@@ -6209,6 +6209,13 @@ qemuMonitorJSONAttachCharDevCommand(const char *chrID,
         break;
 
     case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
+        backend_type = "spicevmc";
+
+        if (virJSONValueObjectAppendString(data, "type",
+                                           virDomainChrSpicevmcTypeToString(chr->data.spicevmc)) < 0)
+            goto error;
+        break;
+
     case VIR_DOMAIN_CHR_TYPE_SPICEPORT:
     case VIR_DOMAIN_CHR_TYPE_PIPE:
     case VIR_DOMAIN_CHR_TYPE_STDIO:

tests/qemumonitorjsontest.c

@@ -769,7 +769,7 @@ testQemuMonitorJSONAttachChardev(const void *data)
     CHECK("chr_unix", "{\"return\": {}}");
 
     chr = (virDomainChrSourceDef) { .type = VIR_DOMAIN_CHR_TYPE_SPICEVMC };
-    CHECK_FAIL("chr_spicevmc", "{\"return\": {}}");
+    CHECK("chr_spicevmc", "{\"return\": {}}");
 
     chr = (virDomainChrSourceDef) { .type = VIR_DOMAIN_CHR_TYPE_PIPE };
     CHECK_FAIL("chr_pipe", "{\"return\": {}}");