[Libvir] New XML attributes for virtio

[Daniel Veillard]

On Fri, Feb 01, 2008 at 06:01:28PM +0100, Soren Hansen wrote:
> Hi!
> 
> I filed https://bugzilla.redhat.com/show_bug.cgi?id=431063 yesterday to
> track this issue.
> 
> Quoting the bug report:
> 
> "To use the new virtio capabilites available in kvm 60, special command
> line paramaters need to be passed to kvm.  There should be a way to
> specify that a device should use virtio in the libvirt xml.
> 
> I propose adding a "model" attribute to the interface element in the XML
> to be able to specify the type of NIC to emulate, e.g. 'virtio'.

 Sounds reasonable

> For the disk virtio I propose adding an 'interface' attribute to target
> element (inside the disk element). This interface could then be set to
> 'virtio', 'ide', 'scsi', etc.."
> 
> Since I wrote the bug report, I noticed there's no way to specify which
> graphics card, you'd like to emulate. A 'model' attribute could probably
> be added to the graphics element as well.
> 
> Comments?

  As the focus is shifting toward fully virtualized, the range of emulated
hardware will grow. Hopefully underneath this will always be QEmu so
these descriptions are likely to be shareable between Xen and KVM. Still
we should not rush and try to design the XML description in an hypervisor
agnostic way.

  For example 'virtio' 'ide' 'scsi' are generic terms, you could have
different SCSI emulated, or different IDE ... For NICs QEmu can already 
emulate mutiple kind of cards. I'm not sure there is a choice for the 
graphic card yet.

  It's unclear to me how specific those descriptions must be, it looks
like a trade-off between being generic (i.e. having similar kind of 
configs at the XML level for different hypervisor) and more flexibility
per engine.

  On a similar note we also need to add sound card support 
    https://bugzilla.redhat.com/show_bug.cgi?id=236800
and maybe allowing generic USB devices would be nice too.

Daniel

-- 
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Daniel Veillard      | virtualization library  http://libvirt.org/
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