Re: [libvirt] [PATCH] qemu: use 'bochs' video type by default for UEFI domains

Hi, > Incidentally, and I haven't followed this closely so apologies if I'm > asking a silly question, if the point of bochs-display is to have a > video device without legacy VGA emulation then why aren't we using > the existing virtio-gpu, which has been around a lot longer and has > better support throughout the stack, instead? Well, virtio-gpu (on x86) actually is "-device virtio-vga". That comes with legacy VGA emulation, for the boot display ... For UEFI guests with virtio-gpu support it is possible to use "-display virtio-gpu-pci" instead (simliar to arm). Only drawback is that you can't have a EFI GOB with virtio-gpu-pci, so efifb doesn't work. Linux kernel console shows up after the virtio-gpu driver loads, which is rather late compared to efifb. For UEFI guests without virtio-gpu support "-device virtio-gpu-pci" will not work due to the lack of EFI GOB support. For these guests "-display bochs-display" should preferred over "-device VGA", to get rid of the unused legacy VGA emulation (and thereby reduce the attack surface). Also note that bochs-display can be plugged into pcie slots (that is true for virtio-gpu-pci too btw).