Re: [libvirt] [PATCH] domain_conf: Include the correct console alias

28 Jun 2013

      On Fri, Jun 28, 2013 at 04:45:08PM +0200, Michal Privoznik wrote:
...
On 28.06.2013 15:55, Daniel P. Berrange wrote:
...
On Fri, Jun 28, 2013 at 03:31:17PM +0200, Michal Privoznik wrote:
...
For some crazy backward compatibility, a console can by just an alias to
a serial device. This is detected in the XML formating function which
takes the values to format from corresponding serial device. Including
the device alias. This results in wrong alias being written into the XML
definition:
<console type='pty' tty='/dev/pts/5'>
      ...
      <alias name='serial0'/>
    </console>
While holding the correct alias still in the memory, it doesn't matter.
However, it starts to matter as soon as libvirtd is restarted and the
(incorrect) alias is read from status file.
I don't actually see this problem at all.

Starting with a guest containing

    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>

After virsh start, it contains

    <serial type='pty'>
      <source path='/dev/pts/7'/>
      <target port='0'/>
      <alias name='serial0'/>
    </serial>
    <console type='pty' tty='/dev/pts/7'>
      <source path='/dev/pts/7'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>

The XML in $XDG_RUNTIME_DIR/libvirt/qemu/run/vm1.xml contains
exactly the same.

If i now kill libvirtd and restart it, the XML is still
reported correctly.

How do you reproduce the bug ?
...
...
This isn't any more correct that your previous patch. For the
dummy <console> elements, the alias *must* be copied from /
identical to the corresponding <serial> device config.
Daniel
So what are you saying is, it's the <serial> that has the wrong alias
assigned? The output should be like this then?
<serial type='pty'>
      <source path='/dev/pts/5'/>
      <target type='isa-serial' port='0'/>
      <alias name='console0'/>
      <!-- originaly was serial0 -->
    </serial>
<console type='pty' tty='/dev/pts/5'>
      <source path='/dev/pts/5'/>
      <target type='serial' port='0'/>
      <alias name='console0'/>
    </console>
No, the alias name must match that of the device id= parameter in the
QEMU command line which is 'serial0' for a serial port.

Daniel
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