qemu/kvm: connect two machines via ttyS0

Question

I would like to connect two machines via ttyS0

Here's what I did on the guest machines:

A:

• Add to /etc/inittab:

  S0:2345:respawn:/sbin/mingetty ttyS0

• Add to /etc/securetty:

  ttyS0

B:

• Try to connect to A

  cu -l /dev/ttyS0

Here's what I did on the host machine:

mkfifo /tmp/serialbridge
qemu-system-x86_64 -hda A.qcow2 -net nic -net user -m 2048 -enable-kvm -cpu host -machine type=pc,accel=kvm -serial pipe:/tmp/serialbridge
qemu-system-x86_64 -hda B.qcow2 -net nic -net user -m 2048 -enable-kvm -cpu host -machine type=pc,accel=kvm -serial pipe:/tmp/serialbridge

I guess the paramter "-serial pipe:/tmp/serialbridge" is wrong. Any ideas how to fix that?

(Qemu is self-compiled from the latest Git tree.)

Result: cu doesn't show login, but rather seems stuck. The other machine seems to hang after login screen. Both run Debian Squeeze.