On Sat, Jul 22, 2023 at 04:11:07PM +0800, suijingfeng wrote: > ... > In the future, we may want to expand VGAARB to deal all PCI display class > devices, with another patch. > > if (pdev->class >> 16 == PCI_BASE_CLASS_DISPLAY) > > // accept > > else > > // return immediately. > > > Then, we will have a more good chance to clarify the programmer interface. I would prefer not to expand vgaarb to deal with all display devices unless they actually need the legacy resources like [pci 0xa0000-0xbffff]. But maybe the consumer of these interfaces relies on vgaarb even for devices that don't need those resources? If so, please mention examples of where they depend on vgaarb. I expect the vgaarb interfaces are used by things that need to emulate the option ROM to initialize the device. If the device has a programming interface other than 0000 0000b, the option ROM should not be using the [pci 0xa0000-0xbffff] resource, so vgaarb should not be needed. Bjorn