qemu: Change default video model type to virtio for S390

S390 guests can only support a virtio-gpu-ccw device as a video
device. So set default video model type to VIR_DOMAIN_VIDEO_TYPE_VIRTIO
for S390 guests.
Signed-off-by: NFarhan Ali <alifm@linux.vnet.ibm.com>

src/qemu/qemu_domain.c

@@ -5425,7 +5425,7 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
         if (dev->data.video->type == VIR_DOMAIN_VIDEO_TYPE_DEFAULT) {
             if (ARCH_IS_PPC64(def->os.arch))
                 dev->data.video->type = VIR_DOMAIN_VIDEO_TYPE_VGA;
-            else if (qemuDomainIsVirt(def))
+            else if (qemuDomainIsVirt(def) || ARCH_IS_S390(def->os.arch))
                 dev->data.video->type = VIR_DOMAIN_VIDEO_TYPE_VIRTIO;
             else
                 dev->data.video->type = VIR_DOMAIN_VIDEO_TYPE_CIRRUS;

tests/qemuxml2argvdata/video-virtio-gpu-ccw-auto.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1803</uuid>
+  <memory>219136</memory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio'>hvm</type>
+  </os>
+  <devices>
+    <emulator>/usr/bin/qemu-system-s390x</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='virtio'/>
+    </disk>
+    <graphics type='vnc'/>
+    <panic model='s390'/>
+  </devices>
+</domain>

tests/qemuxml2xmloutdata/video-virtio-gpu-ccw-auto.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1803</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio'>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-system-s390x</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='virtio'/>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
+    </disk>
+    <graphics type='vnc' port='-1' autoport='yes'>
+      <listen type='address'/>
+    </graphics>
+    <video>
+      <model type='virtio' heads='1' primary='yes'/>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0001'/>
+    </video>
+    <memballoon model='virtio'>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0002'/>
+    </memballoon>
+    <panic model='s390'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -1187,6 +1187,13 @@ mymain(void)
             QEMU_CAPS_VIRTIO_GPU_MAX_OUTPUTS,
             QEMU_CAPS_VNC,
             QEMU_CAPS_DEVICE_VIRTIO_GPU_CCW);
+    DO_TEST("video-virtio-gpu-ccw-auto",
+            QEMU_CAPS_VIRTIO_CCW,
+            QEMU_CAPS_DEVICE_VIRTIO_GPU,
+            QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
+            QEMU_CAPS_VIRTIO_GPU_MAX_OUTPUTS,
+            QEMU_CAPS_VNC,
+            QEMU_CAPS_DEVICE_VIRTIO_GPU_CCW);
 
     DO_TEST("intel-iommu",
             QEMU_CAPS_DEVICE_INTEL_IOMMU);