Avi Kivity wrote: > Anthony Liguori wrote: >>> >>> This ABI breakage is worrying. While it is expected to take some >>> time for the ABI to congeal, we need some way to prevent mismatched >>> guests and hosts from running. Perhaps something like the kvm abi >>> version, storedin the pci revision field? Keep incrementing it >>> until we are satisfied, then use feature bits to add functionality. >> >> This breakage wasn't actually necessary. We could have used a >> feature bit to indicate the additional net config field. In the very >> least, the additional net config field could have been added to the >> end of the config space so that old guests kept working that didn't >> use GSO. >> >> I don't think we need another mechanism to avoid breakages in the >> future. I think we have to declare that whatever ships in 2.6.25 is >> the stable ABI and make sure not to break it again in the future. > > I'm worried about the ramp up to 2.6.25 causing confusion among users > as before that things will break left and right, if we don't provide a > tighter check. >
Well, using the PCI revision ID isn't a bad idea. It wouldn't have helped this last problem because that was an ABI break in the network driver and we really can't indicate a ABI break in the PCI driver for any possibly virtio device. However, if we change the PCI ABI, we can be a little more friendly about it. Just sent out patches. Regards, Anthony Liguori ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
