Re: [Qemu-devel] [Spice-devel] Advice on some configuration parameters

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 03/01/2013 11:02 AM, Fabio Fantoni wrote:
> Il 12/02/2013 14:05, Fabio Fantoni ha scritto:
>> I'm making patches to enable some qemu upstream features in xen that are missing in libxl.
>> I'm trying to do it just by giving arguments to qemu, and I want them to be dynamic (e.g. without physical addresses if possible) and concise.
>>
>> I'm confused about usb configuration.
>>
>> Looking at what virt-manager does, it seems that you set the usbredirection in channels like this:
>> -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0
>>
>> At the moment I'm defining the physical usb devices like this:
>> -readconfig /etc/qemu/ich9-ehci-uhci.cfg
>>
>> If I try to set up virt-manager so that it doesn't point to a file, it uses this configuration:
>>
>> -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x5.0x7
>> -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x5
>> -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x5.0x1
>> -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x5.0x2
>>
>> This seems to differ from the configuration file, e.g. you have multifunzion=on only on the first uhci

That does not matter the multifunction bit needs to set only on 0x5.0x0.

> besides I can't understand how many physical ports are defined.

6, the same as with the "-readconfig /etc/qemu/ich9-ehci-uhci.cf" directive.

> I tried setting 9 usbredirection channels in virt-manager but that configuration doesn't change and no errors are reported, but I doubt that physical ports are being define dynamically.

Hmm, that would be a libvirt bug you should be able to add only 6
usb-redir channels, unless you add a second usb controller ...

Possibly libvirt is also adding a hub? That would work sort-of, it
would make channels 6-9 be usb-1 only, since we don't emulate
usb-2 hubs.

>>
>> Can you omit physical addresses?

In most cases yes, then qemu will pick one itself.

>> I searched the web but I can't find detailed informations about it. Can someone explain in detail how you are supposed to configure usb physical ports? I want to enable both usb redirection and usb passthrough in a dynamic and concise manner.

The easiest way to do is probably to create the setup you want using
virt-manager and then run the vm once, after that the xml file
should contain fixed addresses for all devices.

>>
>> About spice vdagent at the moment I'm using this configuration that seems to work:
>> -device virtio-serial -chardev spicevmc,id=vdagent,name=vdagent -device virtserialport,chardev=vdagent,name=com.redhat.spice.0
>>
>> But I noticed that virt-manager use this slightly different one:
>> -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev spicevmc,id=charchannel0,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0
>>
>> Are there any problem with the more concise one I'm using?

No.

Regards,

Hans