On 08/22/17 16:31, Ard Biesheuvel wrote: > [...] >>> >>> (1) When we added VirtioGpuDxe to the ArmVirtPkg platforms, the only >>> reason I didn't propose removing QemuVideoDxe from the same platforms >>> was that QemuVideoDxe was usable on QEMU/TCG, and I figured it wouldn't >>> hurt to keep it. >>> >>> Other than that, I see zero point in using this driver on ARM. (And, >>> apparently, it does hurt to keep it.) >>> >>> Can we please consider simply removing this driver from the ArmVirtPkg >>> platforms? (And then some now-conditional compilation could be >>> simplified in the driver too!) >>> >> >> It is actually quite useful in TCG mode, and the fact that QEMU >> currently allows unaligned accesses to device memory is not something >> we should be relying upon. >> > > Actually, I managed to confuse myself here. The only thing lacking > when running with virtio-gpu rather than VGA is efifb support, due to > the fact that the framebuffer is no longer directly addressable. efifb > is a useful hack on bare metal systems that lack a real framebuffer > driver, but it is hardly something to care deeply about on VMs.
(Some side thoughts: The "virtiodrmfb" driver in the Linux guest works fine with virtio-gpu-pci. It does not activate itself as soon into the boot process as efifb, but it does provide a fully functional character console. And X11 works fine too, with the kernel modesetting driver. Even if efifb had a chance to work (inheriting a framebuffer), it would be supplanted during boot really quickly by virtiodrmfb. So the only consequence of "efifb" not working is that the character console comes to life a bit later, and some early messages are not shown on the VT.) > So I am going to change my mind, and agree with Laszlo: let's remove > QemuVideoDxe from ArmVirtQemu; the longer we wait, the more difficult > it becomes, and only TCG users that rely on a GOP protocol being > exposed with direct framebuffer access are going to be affected in the > first place (if any such use cases exist) I expect this set of users to be empty already. > Laszlo: any ideas or suggestions you may want to share before I start > working on this? Just the above musings. Please go ahead with the QemuVideoDxe removal! Thank you! Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
