On Tue, Apr 16, 2013 at 12:35:29PM -0400, Laine Stump wrote:
On 04/15/2013 06:14 PM, Don Dutile wrote:
On 04/15/2013 04:09 PM, Laine Stump wrote:
On 04/15/2013 06:29 AM, Daniel P. Berrange wrote:
On 04/11/2013 07:23 AM, Michael S. Tsirkin wrote:
On Thu, Apr 11, 2013 at 07:03:56AM -0400, Laine Stump wrote: > On 04/10/2013 05:26 AM, Daniel P. Berrange wrote: >>>> So if we later allowed for mutiple PCI roots, then we'd have >>>> something >>>> like >>>> >>>> <controller type="pci-root" index="0"> >>>> <model name="i440FX"/> >>>> </controller> >>>> <controller type="pci-root" index="1"> >>>> <model name="i440FX"/> >>>> </controller> >>>> <controller type="pci" index="0"> <!-- Host bridge 1 --> >>>> <address type='pci' domain='0' bus='0' slot='0''/> >>>> </controller> >>>> <controller type="pci" index="0"> <!-- Host bridge 2 --> >>>> <address type='pci' domain='1' bus='0' slot='0''/> >>>> </controller>
There is a problem here - within a given controller type, we will now have the possibility of multiple controllers with the same index - the differentiating attribute will be in the<address> subelement, which could create some awkwardness. Maybe instead this should be handled with a different model of pci controller, and we can add a "domain" attribute at the toplevel rather than specifying an<address>? IIUC there is a limit on the number of PCI buses you can create per domain, due to fixed size of PCI addresses. Google suggests to me
On Fri, Apr 12, 2013 at 11:46:15AM -0400, Laine Stump wrote: the limit is 256. So for domain 1, we could just start index at 256, and domain 2 at 512, etc
Okay. Whether we choose that method, or a separate domain attribute, I'm satisfied that we'll be able to find a way to solve it when the time comes (and it hasn't yet), so we can ignore that problem for now.
*PLEASE* don't create a new/competing naming/numbering scheme for differentiating PCI domains.... as much as I dislike the overuse of the term 'domain', it's what is used. No sane person is going to look to assign PCI bus numbers > 256 in order to get new/different domains. The name sucks, but that's what it's called in the code, and what customers are use to
I infer from this that you're okay with:
<controller type='pci' domain='n' index='n'>
when defining a new controller (using "index" instead of "bus" is a bit bothersome, but it is following current convention; should we reconsider and just call it "bus" this time?), and:
'index' is standard naming across all libvirt <controller> elements and we should do anything different for PCI. For the same reason I don't want us inventing a new 'domain' attribute here either. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|