Newer versions of systemd etc. seem to require quite a lot of entropy
from /dev/random while booting, which can block and therefore delay the
start of other services (in particular sshd) by more than a minute.
Using the host's /dev/urandom via VirtIO RNG, we can avoid blocking the
guests.
The required kernel options are added for kernel versions 5.4+.
This allows accessing the guests with `virsh console <name>`.
Using a serial console would also be possible but our kernel configs
have no serial drivers enabled, CONFIG_VIRTIO_CONSOLE is enabled though.
So to avoid having to recompile the kernels let's do it this way, only
requires rebuilding the guest images.
References #729.
This simplifies capturing traffic with Wireshark on the host as each of
the guest's interfaces is clearly identified.
The three bridges were previously numbered starting from 0, this scheme
is restored here.
Passthrough mode only works as expected when running as root. On
Debian/Ubuntu systems qemu runs as user 'libvirt-qemu' and group 'kvm'
so all shared files must be chowned to grant access from guests.
Symlinks created on the host are still problematic because the Plan 9
filesystem has no direct notion of symbolic links, see [1].
[1] - http://ericvh.github.com/9p-rfc/rfc9p2000.u.html
Guest and network configuration is setup using the libvirt
virtualization API. The [start|stop]_testing scripts have been updated
accordingly.
qemu/KVM does not currently support a hostfs, so the shared build tree
mount has been dropped for now.
Tobias Brunner