[Qemu-discuss] Serial port in Windows 7 guest on linux (Debian Wheezy 64 bit) host

[Wolfgang Wegner]

Hi list,

I am going mad with setting up a serial port for my
virtual machine.

I have Windows 7 (64 bit) running fine in a virtual
machine on my Debian Wheezy 64 bit host. For optimum
performance, I updated libvirt and spice to get good
graphics performance, and I updated the kernel to
have PCI device pass-through, which I use successfully
to let the windows guest have its own USB controller.

What I do not get to run is the serial port.

My host has 5 serial ports: ttyS0, ttyS4 - ttyS7.
I tried setting up ttyS4 to be used by the virtual
Windows 7 guest as follows, but it did not work
at all:
    <serial type='dev'>
      <source path='/dev/ttyS4'/>
      <target port='1'/>
    </serial>
I would have expected this to give me COM2 in the
Windows guest (with COM1 being the default port
being redirected to some pty), but there is still
only COM1 visible in the guest.

So I tried ttyS0 as COM1, and this works at least
"a bit":
    <serial type='dev'>
      <source path='/dev/ttyS0'/>
      <target port='0'/>
      <alias name='serial0'/>
    </serial>
    <console type='dev'>
      <source path='/dev/ttyS0'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>
(The console part is automatically added by libvirt
when saving the config after editing.)

My problem is that there is some sort of CR-LF
translation done, which is of course not what I
want. I suspect this to be caused by the console
entry, but as I do not know how to get rid of it,
I can not test it.

So, two questions:
- Can anybody confirm if the console entry causes
  the CR-LF translation to occur in the serial
  port communication?
and
- How do I correctly configure one of the higher
  ports as additional serial ports?
or, alternatively
- Can I somehow prevent the console entry to be
  automatically added?

I thought this must be trivial questions and tasks,
but I did not find a solution myself, and seemingly
did not use the correct search keywords either.

Best regards,
Wolfgang