On Mon, Nov 22, 2010 at 04:58:11PM +0200, Gleb Natapov wrote: > On Mon, Nov 22, 2010 at 04:56:16PM +0200, Michael S. Tsirkin wrote: > > On Mon, Nov 22, 2010 at 04:52:32PM +0200, Gleb Natapov wrote: > > > On Mon, Nov 22, 2010 at 04:50:29PM +0200, Michael S. Tsirkin wrote: > > > > On Mon, Nov 22, 2010 at 03:04:51PM +0200, Gleb Natapov wrote: > > > > > On Mon, Nov 22, 2010 at 10:16:57AM +0200, Michael S. Tsirkin wrote: > > > > > > On Mon, Nov 22, 2010 at 09:37:07AM +0200, Gleb Natapov wrote: > > > > > > > > > > It's probably required to make them stable anyway. > > > > > > > > > > > > > > > > > > > Why? > > > > > > > > > > > > > > > > To avoid bus renumbering on reboot after you add a pci-to-pci > > > > > > > > bridge. > > > > > > > > > > > > > > > Why should qemu care? > > > > > > > > > > > > Stable bus numbering is a feature *users* care about, because > > > > > > some Guest OSes get confused when a card gets moved to another > > > > > > bus. > > > > > > > > > > > So if user cares about it it should not change HW configuration of > > > > > QEMU. > > > > > I guess those OSes knows how to handle hot-pluggable equipment > > > > > otherwise > > > > > they will get confused on real HW too. Why QEMU should care to > > > > > preserve > > > > > something in a face of configuration change? > > > > > > > > > > -- > > > > > Gleb. > > > > > > > > We've been there, weren't we? See > > > > http://fedoraproject.org/wiki/Features/KVM_Stable_PCI_Addresses#KVM_Stable_PCI_Addresses > > > > > > > This is about stable HW configuration. > > > > Exactly. We have the same need for nested bridges and devices behind > > them. > > > And now you are talking about topology, not guest assigned bus numbers.
I suspect that if bus numbers change, it has the same effect as topology change on the guest. Need to test though, I'm not sure. > So suddenly you are on my side? I don't even get what are you arguing > about at this point. By this time, I forgot, too :). > -- > Gleb.