Re: [PATCH 0/6] virtio_balloon: virtio 1 support

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Mon, 30 Mar 2015 19:37:08 +0200
"Michael S. Tsirkin" <mst@redhat.com> 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.  But for now, it's not a big change to support a transitional balloon
> device: this has the advantage of supporting existing drivers, transparently.

This is needed to support a ballooner on transports that don't support
mixing legacy and 1.0, right?

> 
> The only issue is with the stats buffer, which has misaligned fields.
> Seems easy to fix by prepending a 6 byte reserved field.

I assume you also define the stats fields to be le for 1.0?

> 
> I'll post spec patch and qemu patches shortly.

I'll defer review until then.

> 
> 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 |  6 ++++++
>  drivers/s390/kvm/virtio_ccw.c       | 10 +++-------
>  drivers/virtio/virtio.c             |  6 ------
>  drivers/virtio/virtio_balloon.c     |  8 ++++++--
>  drivers/virtio/virtio_mmio.c        |  8 --------
>  drivers/virtio/virtio_pci_modern.c  |  3 ---
>  7 files changed, 15 insertions(+), 28 deletions(-)
>