qemu: restrict 'virgl=' option to non-vhostuser video type

vhost-user device doesn't have a virgl option, it is passed to the
vhost-user-gpu helper process instead.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

src/qemu/qemu_command.c

@@ -4542,9 +4542,12 @@ qemuBuildDeviceVideoStr(const virDomainDef *def,
 
     virBufferAsprintf(&buf, ",id=%s", video->info.alias);
 
-    if (video->accel && video->accel->accel3d == VIR_TRISTATE_SWITCH_ON) {
-        virBufferAsprintf(&buf, ",virgl=%s",
-                          virTristateSwitchTypeToString(video->accel->accel3d));
+    if (video->backend != VIR_DOMAIN_VIDEO_BACKEND_TYPE_VHOSTUSER &&
+        video->type == VIR_DOMAIN_VIDEO_TYPE_VIRTIO) {
+        if (video->accel && video->accel->accel3d == VIR_TRISTATE_SWITCH_ON) {
+            virBufferAsprintf(&buf, ",virgl=%s",
+                              virTristateSwitchTypeToString(video->accel->accel3d));
+        }
     }
 
     if (video->type == VIR_DOMAIN_VIDEO_TYPE_QXL) {

tests/qemuxml2argvdata/virtio-options.args

@@ -49,8 +49,7 @@ ats=on \
 ats=on \
 -device virtio-input-host-pci,id=input3,evdev=/dev/input/event1234,bus=pci.0,\
 addr=0x12,iommu_platform=on,ats=on \
--device virtio-gpu-pci,id=video0,virgl=on,bus=pci.0,addr=0x2,iommu_platform=on,\
-ats=on \
+-device virtio-gpu-pci,id=video0,bus=pci.0,addr=0x2,iommu_platform=on,ats=on \
 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0xc,iommu_platform=on,\
 ats=on \
 -object rng-random,id=objrng0,filename=/dev/random \