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Re: [Qemu-devel] [PATCH v2] libvhost-user: fix SLAVE_SEND_FD handling
From: |
Tiwei Bie |
Subject: |
Re: [Qemu-devel] [PATCH v2] libvhost-user: fix SLAVE_SEND_FD handling |
Date: |
Wed, 4 Sep 2019 17:01:55 +0800 |
User-agent: |
Mutt/1.9.4 (2018-02-28) |
On Wed, Sep 04, 2019 at 10:06:55AM +0800, Tiwei Bie wrote:
> On Tue, Sep 03, 2019 at 11:04:22PM +0300, Johannes Berg wrote:
> > From: Johannes Berg <address@hidden>
> >
> > It doesn't look like this could possibly work properly since
> > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD is defined to 10, but the
> > dev->protocol_features has a bitmap. I suppose the peer this
> > was tested with also supported VHOST_USER_PROTOCOL_F_LOG_SHMFD,
> > in which case the test would always be false, but nevertheless
> > the code seems wrong.
>
> Ooops.. I tested `tests/vhost-user-bridge -H`. But as you
> said it worked because VHOST_USER_PROTOCOL_F_LOG_SHMFD has
> been negotiated. Thanks for spotting this!
>
> >
> > Use has_feature() to fix this.
> >
> > Fixes: d84599f56c82 ("libvhost-user: support host notifier")
>
> Cc: address@hidden
>
> > Signed-off-by: Johannes Berg <address@hidden>
> > ---
> > contrib/libvhost-user/libvhost-user.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/contrib/libvhost-user/libvhost-user.c
> > b/contrib/libvhost-user/libvhost-user.c
> > index 6a02eaffc672..fcf4a8a00ed2 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -1097,7 +1097,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq
> > *vq, int fd,
> >
> > vmsg.fd_num = fd_num;
> >
> > - if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) ==
> > 0) {
> > + if (!has_feature(dev->protocol_features,
> > + VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) {
>
> We have both of has_feature() and vu_has_feature() called by
> other code in this file directly. Not sure which one is preferred..
> Personally, I think vu_has_feature() might be better.
Thanks for the patch introducing vu_has_protocol_feature().
This fix looks good to me. Thanks a lot!
I'm not the maintainer. But anyway, if this helps:
Reviewed-by: Tiwei Bie <address@hidden>