qemu: Add support for virtio-vga/gpu's max_outputs= parameter

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1449712Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

src/qemu/qemu_command.c

@@ -4484,6 +4484,11 @@ qemuBuildDeviceVideoStr(const virDomainDef *def,
             if (video->heads)
                 virBufferAsprintf(&buf, ",max_outputs=%u", video->heads);
         }
+    } else if (video->type == VIR_DOMAIN_VIDEO_TYPE_VIRTIO) {
+        if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_GPU_MAX_OUTPUTS)) {
+            if (video->heads)
+                virBufferAsprintf(&buf, ",max_outputs=%u", video->heads);
+        }
     } else if (video->vram &&
         ((video->type == VIR_DOMAIN_VIDEO_TYPE_VGA &&
           virQEMUCapsGet(qemuCaps, QEMU_CAPS_VGA_VGAMEM)) ||

tests/qemuxml2argvdata/qemuxml2argv-video-virtio-vga.args

@@ -22,5 +22,5 @@ server,nowait \
 -drive file=/var/lib/libvirt/images/QEMUGuest1,format=qcow2,if=none,\
 id=drive-ide0-0-0,cache=none \
 -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
--device virtio-vga,id=video0,bus=pci.0,addr=0x2 \
+-device virtio-vga,id=video0,max_outputs=1,bus=pci.0,addr=0x2 \
 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvtest.c

@@ -1883,7 +1883,8 @@ mymain(void)
     DO_TEST("video-virtio-vga",
             QEMU_CAPS_DEVICE_VIRTIO_GPU,
             QEMU_CAPS_DEVICE_VIRTIO_VGA,
-            QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
+            QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
+            QEMU_CAPS_VIRTIO_GPU_MAX_OUTPUTS);
     DO_TEST_PARSE_ERROR("video-invalid", NONE);
 
     DO_TEST("virtio-rng-default",