Red Hat Bugzilla – Bug 823879
Parallel port not working in guest, wrong commandline for qemu generated
Last modified: 2012-06-04 18:50:31 EDT
Description of problem:
Pass the /dev/parport0 to guest does not work with qemu-kvm
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Configure /dev/parport0
2. Start guest and try to use the parallel port.
The commandline produced by libvirt looks like this:
The first parameter is "tty". Should not it be "parport"?
If I start the qemu in the commandline with tty replaced with parport it is working as expected.
I will try to provide a patch that fix this issue.
There was also a post in the libvirt-users mailinglist from an other users a couple of months ago:
(In reply to comment #0)
> The first parameter is "tty". Should not it be "parport"?
> If I start the qemu in the commandline with tty replaced with parport it is
> working as expected.
> I will try to provide a patch that fix this issue.
Thanks; if you have questions, I'm sure folks on the list would be glad to answer them.
Created attachment 586043 [details]
Patch that fixes the wrong commandline generated by libvirt for qemu parallel port support
Not sure if this is fix is very clean, but for my case it works.
Perhaps it should also be check if similar problems / patches are required for other chardev backends.
Would you mind sending the patch to firstname.lastname@example.org as well?
Patch posted to the email@example.com.
Fix will be in 0.9.13.
Author: Beat Jörg <Beat.Joerg@ssatr.ch>
Date: Wed May 23 07:50:02 2012 +0200
Fix for parallel port passthrough for QEMU
I came across a bug that the command line generated for passthrough
of the host parallel port /dev/parport0 by libvirt for QEMU is incorrect.
It currently produces:
The first parameter is "tty". It sould be "parport".
If I launch qemu with -chardev parport,... it works as expected.
I have already filled a bug report (
https://bugzilla.redhat.com/show_bug.cgi?id=823879 ), the topic was
already on the list some months ago: