Re: [dpdk-dev] [PATCH 0/4] Some fixes for vhost zero copy

[Tiwei Bie <tiwei.bie@intel.com>]

On Tue, Feb 26, 2019 at 03:46:41PM +0100, Maxime Coquelin wrote:
> On 2/22/19 3:42 AM, Tiwei Bie wrote:
> > Tiwei Bie (4):
> >    vhost: restore mbuf first when freeing zmbuf
> >    vhost: fix potential use-after-free for zero copy mbuf
> >    vhost: fix potential use-after-free for memory region
> >    doc: improve vhost zero copy guide
> > 
> >   doc/guides/prog_guide/vhost_lib.rst |  3 +++
> >   lib/librte_vhost/vhost.h            | 34 +++++++++++++++++++++++
> >   lib/librte_vhost/vhost_user.c       | 42 ++++++++++++++++++++++-------
> >   lib/librte_vhost/virtio_net.c       | 34 -----------------------
> >   4 files changed, 70 insertions(+), 43 deletions(-)
> > 
> 
> Looking at the spec, I think we may need also to drain zmbufs in the
> VHOST_USER_SET_VRING_ENABLE for the disable case:
> 
> ""
> If VHOST_USER_F_PROTOCOL_FEATURES has been negotiated, the ring is
> initialized
> in a disabled state. Client must not pass data to/from the backend until
> ring is enabled by
> VHOST_USER_SET_VRING_ENABLE with parameter 1, or after it has been disabled
> by
> VHOST_USER_SET_VRING_ENABLE with parameter 0.
> 
> Each ring is initialized in a stopped state, client must not process it
> until
> ring is started, or *after it has been stopped*.
> ""
> 
> Do you take care of this or I send a patch on top?

Agree. Please feel free to send any patch on top.

Thanks!
Tiwei

> 
> Thanks,
> Maxime