Comment 3 for bug 1867519

I got VFs enabled now, attach works fine as well.

But I can confirm that detach breaks it.

XML used for the device:
  <interface type='hostdev' managed='yes'>
    <driver name='vfio'/>
      <mac address='52:54:00:c3:0e:32'/>
    <source>
      <address type='pci' domain='0x0000' bus='0x08' slot='0x00' function='0x2'/>
    </source>
  </interface>

$ virsh detach-device focal-pttest VF-pass-through.xml
error: Failed to detach device from VF-pass-through.xml
error: internal error: End of file from qemu monitor

Logs:
1. Guest dmesg (doesn't exist as it dies immediately).

2. qemu log:
2020-03-18 11:02:18.221+0000: shutting down, reason=crashed

This one is interesting, Host dmesg:
[ 5819.223023] CPU 0/KVM[2763]: segfault at 0 ip 000055d37b4b245d sp 00007f2f5fffe188 error 6 in qemu-system-x86_64[55d37b008000+529000]
[ 5819.223030] Code: 08 48 89 50 10 48 89 37 48 89 7e 10 c3 f3 0f 1e fa 48 8b 47 08 48 8b 57 10 48 85 c0 74 0c 48 89 50 10 48 8b 57 10 48 8b 47 08 <48> 89 02 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e

Afterwards I see the device come back to the host, but the segfault is the reason it died.