On 1 September 2016 at 20:52, Jordan Justen <jordan.l.jus...@intel.com> wrote: > On 2016-09-01 11:46:04, Laszlo Ersek wrote: >> On 09/01/16 20:03, Jordan Justen wrote: >> >> > I think there would be value to have a non-VGA device that could still >> > configure a simple framebuffer. VGA does bring a fair amount of other >> > baggage. >> >> Ah, I see your point. You distinguish "VGA" from "non-VGA device with >> framebuffer". >> >> For this discussion however, this distinction makes no difference. The >> suggested "non-VGA device with framebuffer" would be broken exactly the >> same way. In other words, it's not the "other baggage" that is broken, >> it is the framebuffer. >> > > This is only focusing on the current ARM issue. I'm just pointing out > that I think virtio gpu without VGA, but with a framebuffer could be > useful on IA32/X64 as well. > > 1. You don't have to deal with the PCI bus > > 2. The OS re-enumerating the PCI bus would not break the framebuffer >
How does adding a framebuffer to virtio-gpu solve any of that? virtio-gpu is a PCI device as well > Is there no chance that ARM KVM might someday also be able to support > a framebuffer? > There are workarounds imaginable, but none of them are feasible in terms. A new revision of the architecture may address this, but that will take years to turn up in real hardware. > Obviously this is not too important for IA32/X64 OVMF, because we have > reasonable alternatives. But, it seems like virtio gpu could be a > significantly better option for IA32/X64 OVMF if an optional > framebuffer was possible. > IIUC, not having a linear framebuffer was one of the design goals, since it is essentially a layering violation in the virtio stack. virtio-gpu is strictly ring based, like other virtio devices. If you want a framebuffer, you should use virtio-vga. Adding a framebuffer to virtio-gpu is a step back rather than a step forward. Also, the loader->OS handover already suffers from the issues you mention, since the PCI reconfiguration breaks GOP on almost every platform. The reason that it is less of a concern on ARM is that most systems use UART as the primary console. _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
