Re: [Libvir] RFC: format for mapping host devices to guest

On Thu, Jul 19, 2007 at 06:17:29AM -0400, Daniel Veillard wrote: > > IMHO you should output both, then depending how you will reuse that XML > fragment one or the other may be used, this could actually be one argument to > split the device definition entry point and the device modification. For > the definition you would use the vendor/product identifiers, while for example > to simulate a disk change on an USB CDRom reader you would use device numbers. > > <host bus='usb'> > <device vendor='0471' product='0311' name='Philips PCVC740K ToUcam Pro'/> > <source dev='003.001'/> > <target dev='001.005'/> > </host> > > At the XML format you would require device or source to be present, possibly > both and name would be an optional attribute (which need to be XML escaped). The name doesn't belong here. I've got a separate email to write about a way to enumerate devices on the host - currently virt-manager just calls HAL which obviously doesn't work for remote management. So we need an API for enumerating physical devices - the 'name' attribute for the devices is better placed in there, rather the duplicating in the per-VM config.

> > Now PCI would be similar - no hotplug to worry about here though, and no > > need (or availability) or target info. So the XML would simply be > > > > <host bus='pci'> > > <source dev='00:1f.3'/> > > </host> > > > > You may still have twice the same kind of card plugged on a PCI bus > so just vendor/product doesn't sound sufficient to me. PCI device are > more likely to be static, I would consider vendor/product to be user > informations, but the code would always use the device if present. That PCI dev ID is unique AFAIK - the 3 components uniquely identify the PCI device encoding bus+slot or something like that - this is basically the info from 'lspci' on Linux.