Lastly, observed the same behavior by removing the pcihole64 attribute and setting the X-PciMmio64Mb configuration to 2TB. > >> Or perhaps that would be too messy or x86-centric and itâ??s better to go >> with what you proposed (pcimmio64)? > > If the 'pcihole64' setting really is setting the MMIO64 window, then it > would be preferrable to re-use the existing setting field. Per the tests above, pcihole64 is setting the MMIO64 window. The only concern I have with using it is that to date, it has been an x86-centric attribute and tied closely with the qemu -global parameter. I donâ??t think this is a show-stopper, but will require some code changes to allow it to work with the virt machine and connect it up to a different qemu parameter for that machine. -matt