On Wed, Jun 17, 2020 at 12:57 PM Laszlo Ersek <ler...@redhat.com> wrote: > [...] > I don't necessarily see compat issues -- large-BAR PCI device assignment > might simply stop working under those circumstances, because you could > no longer use X-PciMmio64Mb, and the new way wouldn't be supported by > (old) QEMU. > > This would indeed be a regression relative to "X-PciMmio64Mb", but > that's exactly why there's an "X" in "X-PciMmio64Mb". >
Are you planning to remove that option, with this improvement? I think we could keep it for a while, as a way to override the automatic mechanism we might implement. This is even for "safe" purposes, in case there's some corner case with the auto-sized aperture that we ignore upfront. > > So, the code may be a bit complex, it'll > > need to take into account this case (probably we could just rely on > > the physbits "detected" by OVMF in such case, limiting PCI64 aperture > > to the current 36-bits, right?). > > A "bit complex" is an understatement. The code is already much more >[...] heheh indeed, it's very complex code! It took me a while to even start to figure where things are done, I guess UEFI spec is complex in nature too, which adds to that code complexity!
