[libvirt] [PATCHv2] qemu: Fix PCI address allocation

[Daniel Veillard]

On Tue, Aug 03, 2010 at 03:17:01PM -0600, Eric Blake wrote:
> From: Jiri Denemark <jdenemar at redhat.com>
> 
> When attaching a PCI device which doesn't explicitly set its PCI
> address, libvirt allocates the address automatically. The problem is
> that when checking which PCI address is unused, we only check for those
> with slot number higher than the highest slot number ever used.
> 
> Thus attaching/detaching such device several times in a row (31 is the
> theoretical limit, less then 30 tries are enough in practise) makes any
> further device attachment fail. Furthermore, attaching a device with
> predefined PCI address to 0:0:31 immediately forbids attachment of any
> PCI device without explicit address.
> 
> This patch changes the logic so that we always check all PCI addresses
> before we say there is no PCI address available.
> 
> Signed-off-by: Eric Blake <eblake at redhat.com>
> ---
> 
> Modifications from v1: revert back to remembering the last slot
> reserved, but allow wraparound to not be limited by the end.
> In this way, slots are still assigned in the same order as
> before the patch, rather than filling in the gaps closest to
> 0 and risking making windows guests mad.

  ACK, that looks fine, I will push it once as part of my 0.8.3 release
within an hour or so !

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/