Re: [libvirt] [PATCH 2/2] qemu: Update next usable PCI slot on domain reconnect

> 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.