Re: [libvirt] Fwd: Re: need your help about virito vmchannel

On 05/04/2010 12:38 PM, Matthew Booth wrote: > FYI for the list. I haven't looked at this yet. > > Matt > > -------- Original Message -------- > Subject: Re: need your help about virito vmchannel > Date: Tue, 4 May 2010 18:00:02 +0530 > From: Amit Shah <amit.shah(a)redhat.com&gt; > To: Matthew Booth <mbooth(a)redhat.com&gt; > CC: Jianlin Liu <jialiu(a)redhat.com&gt; > > On (Tue) May 04 2010 [13:18:30], Matthew Booth wrote: >> On 04/05/10 12:48, Jianlin Liu wrote: >>> Hi Matthew, >>> >>> I want to create a virtio vm channel in my guest. So I add the followiong to my guest xml file: >>> <channel type='pty'> >>> <target type='virtio' name='org.linux-kvm.port.0'/> >>> </channel> >> >> Jianlin, >> >> While I wrote the libvirt->vmchannel glue, I'm not actually that >> familiar with vmchannel itself. I've cc'd Amit, who hopefully might >> recognise this problem and tell me how to fix it ;) >> >> Amit, >> >> Any idea what's going on here? > > Yes: > >>> Then I try to start the guest: >>> # virsh start winxp >>> error: Failed to start domain winxp >>> error: internal error Process exited while reading console log output: char device redirected to /dev/pts/4 >>> char device redirected to /dev/pts/5 >>> qemu-kvm: -device virtio-serial-pci,id=virtio-serial0,max_ports=0,vectors=0,bus=pci.0,addr=0x5: Device 'virtio-serial-pci' could not be initialized > > With max_ports=0, the virtio-serial device doesn't get created and hence > this error. > > Amit > I saw this issue as well, when I started adding channel support to virt-install (since stalled, but mostly complete). Adding a <channel> device creates an implicit virtio-serial controller which defaults to ports = 0. Since ports = 0 is useless, maybe we should just defer to the qemu default for that case (which is 31 according to http://fedoraproject.org/wiki/Features/VirtioSerial ). We should probably find a way to do the same thing for the 'vectors' value as well, although 0 is valid value there.