Re: [Qemu-devel] [Xen-devel] [PATCH 0/4] virtio-net: do not leak cpu mappings

[Fabio Fantoni]

Il 25/11/2014 15:42, Stefano Stabellini ha scritto:
> Hi all,
> this patch series fixes a cpu mapping leak in virtio-net.
>
> The bug is caused by virtio_net_handle_ctrl: it maps the entire out_sg
> iov, but then modifies it and reduces it (iov_discard_front), and only
> unmap the reduced version of the iov.
>
> This causes a crash when running on Xen, but the behaviour is obviously
> incorrect without Xen too.
>
> The patch series fixes the issue by allowing virtio_net_handle_ctrl to
> unmap the original out_sg iov but still call virtqueue_fill and
> virtqueue_flush on the modified iov.
>
> The first three patches do not introduce any functional changes.

Thanks for these pathes, 1-2 years ago I tried to use virtio net and 
disks on xen unsuccessful and I was unable to solve it.
When I'll have time I'll retry.
About virtio disks can have problem similar to this or should be ok?
About the other patches posted in link below are all not applied and 
should be only rebased or they must be fully revisioned/modified?
http://wiki.xen.org/wiki/Virtio_On_Xen

Thanks for any reply and sorry for my bad english.

> Stefano Stabellini (4):
>        introduce virtqueue_unmap_sg
>        use virtqueue_unmap_sg in virtqueue_fill
>        move virtqueue_unmap_sg calls from virtqueue_fill to virtqueue_push
>        virtio-net: do not leak cpu mappings
>
>   hw/net/virtio-net.c        |    9 ++++++++-
>   hw/virtio/virtio.c         |   43 ++++++++++++++++++++++++-------------------
>   include/hw/virtio/virtio.h |    2 ++
>   3 files changed, 34 insertions(+), 20 deletions(-)
>
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