Re: [PATCH RFC v4 00/16] qemu: towards virtio-1 host support

Michael S. Tsirkin
2014-11-27T15:24:22Z

On Thu, Nov 27, 2014 at 04:16:33PM +0100, Cornelia Huck wrote:
> Yet another version of the virtio-1 support patches.
>
> This one has seen some (very) light testing with the virtio-1 guest
> support patches currently on vhost-next.
>
> Changes from v3:
>
> - Add support for FEATURES_OK. We refuse to set features after the
> driver has set this in the status field, and we allow to fail
> setting the status if the features are inconsistent.
> - Add missing virtio-1 changes for virtio-net (header size and mac).
> - Dropped setting the VERSION_1 bit for virtio-blk: There's still
> some stuff missing.
>
> For virtio-blk, we need to validate the feature bits if version 1 is
> negotiated: some legacy features are not allowed in that case. I'm not
> quite sure how to handle this, though. We could use the new
> validate_features callback to verify that the driver negotiated a
> sensible feature set, but that would require us to offer a superset
> of legacy and version 1 bits, which feels wrong. Any ideas?

No, that's violating the spec.
I think the simplest way is to have separate features and
legacy_features fields. Present the correct one depending on which
revision was negotiated.

> Cornelia Huck (13):
> virtio: cull virtio_bus_set_vdev_features
> virtio: support more feature bits
> s390x/virtio-ccw: fix check for WRITE_FEAT
> virtio: introduce legacy virtio devices
> virtio: allow virtio-1 queue layout
> dataplane: allow virtio-1 devices
> s390x/virtio-ccw: support virtio-1 set_vq format
> virtio: disallow late feature changes for virtio-1
> virtio: allow to fail setting status
> s390x/virtio-ccw: enable virtio 1.0
> virtio-net: no writeable mac for virtio-1
> virtio-net: support longer header
> virtio-net: enable virtio 1.0
>
> Thomas Huth (3):
> linux-headers/virtio_config: Update with VIRTIO_F_VERSION_1
> s390x/css: Add a callback for when subchannel gets disabled
> s390x/virtio-ccw: add virtio set-revision call
>
> hw/9pfs/virtio-9p-device.c | 7 +-
> hw/block/dataplane/virtio-blk.c | 4 +-
> hw/block/virtio-blk.c | 9 +-
> hw/char/virtio-serial-bus.c | 9 +-
> hw/net/virtio-net.c | 52 +++++--
> hw/s390x/css.c | 12 ++
> hw/s390x/css.h | 1 +
> hw/s390x/s390-virtio-bus.c | 9 +-
> hw/s390x/virtio-ccw.c | 206 +++++++++++++++++++------
> hw/s390x/virtio-ccw.h | 7 +-
> hw/scsi/vhost-scsi.c | 7 +-
> hw/scsi/virtio-scsi-dataplane.c | 2 +-
> hw/scsi/virtio-scsi.c | 10 +-
> hw/virtio/Makefile.objs | 2 +-
> hw/virtio/dataplane/Makefile.objs | 2 +-
> hw/virtio/dataplane/vring.c | 96 ++++++------
> hw/virtio/virtio-balloon.c | 8 +-
> hw/virtio/virtio-bus.c | 23 +--
> hw/virtio/virtio-mmio.c | 9 +-
> hw/virtio/virtio-pci.c | 13 +-
> hw/virtio/virtio-rng.c | 2 +-
> hw/virtio/virtio.c | 88 +++++++++--
> include/hw/virtio/dataplane/vring-accessors.h | 75 +++++++++
> include/hw/virtio/dataplane/vring.h | 14 +-
> include/hw/virtio/virtio-access.h | 4 +
> include/hw/virtio/virtio-bus.h | 10 +-
> include/hw/virtio/virtio.h | 39 ++++-
> linux-headers/linux/virtio_config.h | 3 +
> 28 files changed, 523 insertions(+), 200 deletions(-)
> create mode 100644 include/hw/virtio/dataplane/vring-accessors.h
>
> --
> 1.7.9.5