[Qemu-devel] [PATCH 0/4] virtio: Move host features to backends

[Shannon Zhao]

The reason to do this is that the virtio-net-device can't expose host
features to guest while using virtio-mmio. So the performance is low.

The virtio-*-pci, virtio-*-s390, and virtio-*-ccw already have the ability
to forward property accesses to the backend child, by calling 
*_virtio_*_instance_init -> qdev_alias_all_properties.

Here we move the host features to backends, involving
DEFINE_VIRTIO_NET_FEATURES, DEFINE_VIRTIO_SCSI_FEATURES. So the virtio-mmio
devices could have the host freatures, and this has a great performance
improvement to virtio-mmio.

This is also backward compatible for s390 and x86.

Shannon Zhao (4):
  hw/s390x/virtio-ccw: Add virtio_ccw_device_plugged for virtio-ccw
  hw/s390x/s390-virtio-bus: Add virtio_s390_device_plugged for
    s390-virtio
  hw/net/virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net
  virtio-scsi: Move DEFINE_VIRTIO_SCSI_FEATURES to virtio-scsi

 hw/net/virtio-net.c             |  4 ++++
 hw/s390x/s390-virtio-bus.c      | 12 ++++++++++--
 hw/s390x/virtio-ccw.c           | 13 +++++++++++--
 hw/scsi/virtio-scsi.c           |  5 +++++
 hw/virtio/virtio-pci.c          |  2 --
 include/hw/virtio/virtio-net.h  |  1 +
 include/hw/virtio/virtio-scsi.h |  1 +
 7 files changed, 32 insertions(+), 6 deletions(-)

-- 
2.0.4