On Wed, Aug 18, 2010 at 01:15:55PM +0200, Jiri Denemark wrote: > > Why do we need it to be exactly the same value ? nextslot is just an > > efficiency optimization isn't it. ie, so instead of starting from > > slot 0 and iterating over 'N' already used slots till we find a free > > slot, we can get the next free slot in 1 step. As such do we really > > need to worry about restoring it to the same value after restarting > > libvirtd. > > That was my understanding too. But Eric was concerned (in an older thread) > about hotplugging PCI devices in a nonmonotonic way. He thinks it could upset > Windows guests. Of course, if nextslot ever wraps from > QEMU_PCI_ADDRESS_LAST_SLOT back to zero, such guests would be doomed anyway so > we are only a bit nicer to them. I don't know if this is a real issue or not > since I haven't met a Windows guest which I'd like to hotplug a PCI device in. There's no requirement to plug devices in ascending slot order - we can have gaps at will with any ordering. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list