Anybody interested in looking at this issue? https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1884232 It looks like something wrong in the way we handle "reserved" regions in the e820 map with respect to PCI address assignment. BIOS programmed BAR 0 to [mem 0xfe010000-0xfe010fff], but according to the PCI0 _CRS method, that area is not routed to the PCI bus: ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-fe]) pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window] pci_bus 0000:00: root bus resource [mem 0x3f800000-0xbfffffff window] pci 0000:00:1f.5: [8086:34a4] type 00 class 0x0c8000 pci 0000:00:1f.5: reg 0x10: [mem 0xfe010000-0xfe010fff] pci 0000:00:1f.5: can't claim BAR 0 [mem 0xfe010000-0xfe010fff]: no compatible bridge window pci 0000:00:1f.5: BAR 0: no space for [mem size 0x00001000] pci 0000:00:1f.5: BAR 0: trying firmware assignment [mem 0xfe010000-0xfe010fff] pci 0000:00:1f.5: BAR 0: [mem 0xfe010000-0xfe010fff] conflicts with Reserved [mem 0xfc800000-0xfe7fffff] pci 0000:00:1f.5: BAR 0: failed to assign [mem size 0x00001000]
