Re: [Qemu-devel] [RFC 0/5] virtio: use alias properties in transport devices

[Frederic Konrad <fred.konrad@greensocs.com>]

On 19/03/2014 16:48, Stefan Hajnoczi wrote:
> This RFC is just the beginning.  The same problem exists for virtio-net and
> other devices.  I am looking for feedback before I convert all of virtio.
>
> The virtio transport/device split is broken as follows:
>
> 1. The virtio-blk device is never finalized because the transport devices
>     (virtio-blk-pci and friends) leak the refcount.
>
> 2. If we fix the refcount leak then we double-free the 'serial' string property
>     upon hot unplug since its char* is copied into the virtio-blk device which
>     has an identical 'serial' qdev property.
>
> This series solves both of these problems as follows:
>
> 1. Introduce a qdev child alias property that lets the transport device forward
>     qdev property accesses into the virtio device (the child).
>
> 2. Use qdev child alias properties in transport devices, instead of keeping a
>     duplicate copy of the VirtIOBlkConf struct.
>
> 3. Fix the virtio-blk device refcount leak.  It's now safe to do this since the
>     double-free has been resolved.
>
> Note about the new qdev child alias property type: I haven't made the alias
> fully transparent yet.  Perhaps we should hide the alias completely?
> $ qemu-system-x86_64 -device virtio-blk-pci,\?
> ...
> virtio-blk-pci.logical_block_size=ChildAlias  <--- should be uint64 or similar
>
> Stefan Hajnoczi (5):
>    qdev: add child alias properties
>    virtio: add child alias properties for virtio-blk
>    virtio: use child aliases for virtio-blk transport properties
>    virtio-blk: drop virtio_blk_set_conf()
>    virtio: fix virtio-blk child refcount in transports
>
>   hw/block/virtio-blk.c          |  6 ------
>   hw/core/qdev-properties.c      | 28 ++++++++++++++++++++++++++++
>   hw/s390x/s390-virtio-bus.c     |  4 ++--
>   hw/s390x/s390-virtio-bus.h     |  1 -
>   hw/s390x/virtio-ccw.c          |  6 +++---
>   hw/s390x/virtio-ccw.h          |  1 -
>   hw/virtio/virtio-pci.c         |  6 +++---
>   hw/virtio/virtio-pci.h         |  1 -
>   include/hw/block/block.h       | 14 ++++++++++++++
>   include/hw/qdev-properties.h   | 28 ++++++++++++++++++++++++++++
>   include/hw/virtio/virtio-blk.h | 17 ++++++++++++++++-
>   11 files changed, 94 insertions(+), 18 deletions(-)
>
Hi,

Sorry I missed this.

Is there any repo with those patches I can clone?

Thanks,
Fred