[Pkg-libvirt-maintainers] Bug#924423: In debian testing I can't get PXE boot logs from libvirt guest on a serial console

[Katerina Koukiou]

Package: libvirt
libvirt-daemon 5.0.0-1
qemu 1:3.1+dfsg-4
virt-manager 1:2.0.0-3

# uname -a
Linux unassigned-hostname 4.19.0-2-amd64 #1 SMP Debian 4.19.16-1
(2019-01-17) x86_64 GNU/Linux

Steps to reproduce:

1. Create a libvirt Virtual Network with tftp server configured. Example XML:

# virsh net-dumpxml pxe-nat
<network>
  <name>pxe-nat</name>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:53:7d:8e'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <tftp root='/var/lib/libvirt/pxe-config'/>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
      <bootp file='pxe.cfg'/>
    </dhcp>
  </ip>
</network

2. Create the IPXE configuration file with some dummy message to
expect in the serial console.
# cat /var/lib/libvirt/pxe-config/pxe.cfg
#!ipxe

echo Rebooting in 60 seconds
sleep 60
reboot

3. Create a guest OS with no disks, configured to have network as boot
device. The following virt-install command can be used:

virt-install --name test-1 --pxe --network network=pxe-nat --boot
useserial=yes --console log.file=/tmp/serial.txt --disk none --memory
500

Expected results:
The /tmp/serial file should be populated with the ipxe logs.

Additional info:
journalctl -u libvirtd doesn't have any errors/warnings.
The debian host is actually a VM, with kvm module not loaded, thus I
am using qemu emulation for the nested guest.

Note tha the issue is not related to the serial console to file
redirection. If we don't speficy file type for console and just run
the command like this:
virt-install --name test-1 --pxe --network network=pxe-nat --boot
useserial=yes --nographics --disk none --memory 500

we still will not see the PXE logs in the terminal.

Let me know if I can provide with additional files for debugging.