The virtio-gpu 'blob' support was insufficiently validated. Qemu
requires a memfd memory backing in order to use udmabuf and enable blob
support. Example error:
$ virsh start rhel9
error: Failed to start domain 'rhel9'
error: internal error: qemu unexpectedly closed the monitor: 2023-07-18T02:33:57.083178Z qemu-kvm: -device {"driver":"virtio-vga","id":"video0","max_outputs":1,"blob":true,"bus":"pcie.0","addr":"0x1"}: cannot enable blob resources without udmabuf
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
This can improve performance for some guests since it reduces copying of
display data between host and guest. Requires udmabuf on the host.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
