On Wed, Apr 01, 2015 at 02:57:35PM +0200, Michael S. Tsirkin wrote: > Virtio 1.0 doesn't include a modern balloon device. At some point we'll likely > define an incompatible interface with a different ID and different > semantics. But for now, it's not a big effort to support a transitional > balloon device: this has the advantage of supporting existing drivers, > transparently, as well as transports that don't allow mixing virtio 0 and > virtio 1 devices. And balloon is an easy device to test, so it's also useful > for people to test virtio core handling of transitional devices. > > The only interface issue is with the stats buffer, which has misaligned > fields. We could leave it as is, but this sets a bad precedent that > others might copy by mistake. > > As we need to change stats code to do byteswaps for virtio 1.0, it seems easy > to fix by prepending a 6 byte reserved field. I also had to change config > structure field types from __le32 to __u32 to match other devices. This means > we need a couple of __force tags for legacy path but that seems minor. Rusty, what are your thoughts here? How about merging this for 4.1? > changes from v2: > fix up stats endian-ness > Changes from v1: > correctly handle config space endian-ness > > Michael S. Tsirkin (6): > virtio_balloon: transitional interface > virtio: balloon might not be a legacy device > virtio_ccw: support non-legacy balloon devices > virtio_mmio: support non-legacy balloon devices > virtio_pci: support non-legacy balloon devices > virtio: drop virtio_device_is_legacy_only > > include/linux/virtio.h | 2 -- > include/uapi/linux/virtio_balloon.h | 11 +++++++++-- > drivers/s390/kvm/virtio_ccw.c | 10 +++------- > drivers/virtio/virtio.c | 6 ------ > drivers/virtio/virtio_balloon.c | 33 +++++++++++++++++++++++---------- > drivers/virtio/virtio_mmio.c | 8 -------- > drivers/virtio/virtio_pci_modern.c | 3 --- > 7 files changed, 35 insertions(+), 38 deletions(-) > > -- > MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
