Kernel panic at boot when networking is enabled

[penberg]

Kernel boot panics when networking is enabled with ./scripts/run --network=user <image>:

Booting kernel ...
Boot loader: 'GRUB 2.03'
Module: 00152000-00155af0
Memory map:
  0000000000000000-000000000009fc00  639 KiB [available]
  000000000009fc00-00000000000a0000    1 KiB [reserved]
  00000000000f0000-0000000000100000   64 KiB [reserved]
  0000000000100000-0000000007fe0000  126 MiB [available]
  0000000007fe0000-0000000008000000  128 KiB [reserved]
  00000000feffc000-00000000ff000000   16 KiB [reserved]
  00000000fffc0000-0000000100000000  256 KiB [reserved]
Found x2APIC at fee00900
Probing PCI devices ...
  00:00.0 0202: 8086:1237 (rev 2)
  00:01.0 0000: 8086:7000 (rev 0)
  00:01.1 0000: 8086:7010 (rev 0)
  00:01.3 0303: 8086:7113 (rev 3)
  00:02.0 0202: 1234:1111 (rev 2)
  00:03.0 0101: 1af4:1041 (rev 1) [msix]
virtio-net: 3 virtqueues found.
Found initrd at 0xffffffff80152000 (15088 bytes)
Page fault at address 0000000000401000
Registers:
  RIP=0000000000401000 CS=0000000000000023 RFLAGS=0000000000010247 RSP=0000000040000000 SS=000000000000001b
  RAX=000000000000001b RBX=ffffffff8015f038 RCX=ffffffff8015d068 RDX=ffffffff8015d048 RBP=0000000000000000
  RSI=0000000040000000 RDI=0000000000401000 R8=0000000000000000  R9=0000000040000000  R10=0000000000000000
  R11=ffffffff80152010 R12=0000000000000000 R13=0000000000000000 R14=ffffffff8015f000 R15=ffffffff8015d020
Kernel panic: Halted
QEMU: Terminated

I tracked the problem down to virtio-net initialization. Likely another issue with PCI BAR remapping.