>with an error message indicating DMA mapping failed for the
passthrough >devices.
A correction - the message indicates UEFI failed to find a mapping for
the boot partition ("map: no mapping found"), not that DMA mapping
failed. But earlier EDK debug logs still show PCI host bridge resource
conflicts for the passthrough devices that seem related to the VM boot
failure.
I have tried a 2023 version EFI which works. And for more recent tests I am
using a one built directly from,
https://github.com/tianocore/edk2.git master
Commit: 0f3867fa6ef0("UefiPayloadPkg/UefiPayloadEntry: Fix PT protection
in 5 level paging"
With both, I don’t remember seeing any boot failure and the above UEFI
related "map: no mapping found" error. But the Guest kernel at times
complaints about pci bridge window memory assignment failures.
...
pci 0000:10:01.0: bridge window [mem size 0x00200000 64bit pref]: can't assign;
no space
pci 0000:10:01.0: bridge window [mem size 0x00200000 64bit pref]: failed to
assign
pci 0000:10:00.0: bridge window [io size 0x1000]:can't assign; no space
...
But Guest still boots and worked fine so far.