qemu: Fix assignment of the default spicevmc channel name

Make sure we only assign the default spicevmc channel name to spicevmc
virtio channels. Caused by commits 3269ee65 and 1133ee2b, which moved
the assignment from XML parsing code to QEMU but failed to keep the
logic.

https://bugzilla.redhat.com/show_bug.cgi?id=1179680

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_command.c

@@ -6427,7 +6427,9 @@ qemuBuildVirtioSerialPortDevStr(virDomainDefPtr def,
           virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_SPICEVMC))) {
         virBufferAsprintf(&buf, ",chardev=char%s,id=%s",
                           dev->info.alias, dev->info.alias);
-        if (dev->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL) {
+        if (dev->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
+            (dev->source.type == VIR_DOMAIN_CHR_TYPE_SPICEVMC ||
+             dev->target.name)) {
             virBufferAsprintf(&buf, ",name=%s", dev->target.name
                               ? dev->target.name : "com.redhat.spice.0");
         }

tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-default.args

@@ -0,0 +1,16 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefconfig -nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/test-monitor,server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=readline \
+-no-acpi \
+-boot c \
+-device virtio-serial-pci,id=virtio-serial1,bus=pci.0,addr=0xa \
+-device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x3 \
+-usb \
+-hda /dev/HostVG/QEMUGuest1 \
+-chardev pty,id=charchannel0 \
+-device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0 \
+-chardev spicevmc,id=charchannel1,name=vdagent \
+-device virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,\
+name=com.redhat.spice.0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4

tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-default.xml

@@ -0,0 +1,36 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='virtio-serial' index='1'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <channel type='pty'>
+      <target type='virtio'/>
+    </channel>
+    <channel type="spicevmc">
+      <target type="virtio"/>
+    </channel>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1110,6 +1110,9 @@ mymain(void)
     DO_TEST("channel-spicevmc-old",
             QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG,
             QEMU_CAPS_SPICE, QEMU_CAPS_DEVICE_SPICEVMC);
+    DO_TEST("channel-virtio-default",
+            QEMU_CAPS_DEVICE, QEMU_CAPS_CHARDEV, QEMU_CAPS_NODEFCONFIG,
+            QEMU_CAPS_SPICE, QEMU_CAPS_CHARDEV_SPICEVMC);
 
     DO_TEST("smartcard-host",
             QEMU_CAPS_CHARDEV, QEMU_CAPS_DEVICE,