Comment 2 for bug 2009048

Test Steps on QEMU 7.2 (lunar-proposed), which addresses the issue:

RELEASE=lunar

 $ apt policy qemu-system-x86
 qemu-system-x86:
   Installed: 1:7.2+dfsg-4ubuntu1
   Candidate: 1:7.2+dfsg-4ubuntu1
   Version table:
  *** 1:7.2+dfsg-4ubuntu1 100
  100 http://security.ubuntu.com/ubuntu lunar-proposed/main amd64 Packages
  100 http://archive.ubuntu.com/ubuntu lunar-proposed/main amd64 Packages
  100 /var/lib/dpkg/status
      1:7.0+dfsg-7ubuntu4 500
  500 http://archive.ubuntu.com/ubuntu lunar/main amd64 Packages

The VM now mentions it needs more phys-bits for the 1+ TiB assignment/usage (~2 TiB in this example)

 $ sudo qemu-system-x86_64 -nographic -device vfio-pci,host=$PCI -m 2048000
 qemu-system-x86_64: Address space limit 0xffffffffff < 0x2f3bfffffff phys-bits too low (40)

If the physical bits are specified, the VFIO MAP DMA error no longer happens,
and we proceed to out-of-memory as expected.

 $ sudo qemu-system-x86_64 -nographic -device vfio-pci,host=$PCI -m 2048000 -cpu qemu64,phys-bits=48
 [ 578.875598] Out of memory: Killed process 2715 (qemu-system-x86) total-vm:2098083568kB, anon-rss:3749768kB, file-rss:2640kB, shmem-rss:0kB, UID:0 pgtables:7524kB oom_score_adj:0