Re: [PATCH net-next 01/11] net: sock: introduce SOCK_XDP

[Jason Wang <jasowang@xxxxxxxxxx>]

On 2018年09月07日 00:56, Michael S. Tsirkin wrote:
> On Thu, Sep 06, 2018 at 12:05:16PM +0800, Jason Wang wrote:
> > This patch introduces a new sock flag - SOCK_XDP. This will be used
> > for notifying the upper layer that XDP program is attached on the
> > lower socket, and requires for extra headroom.
> >
> > TUN will be the first user.
> >
> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> In fact vhost is the 1st user, right? So this can be
> pushed out to become patch 10/11.

Better with an independent patch, since patch 10/11 can work without XDP.

Thanks

> > ---
> >   drivers/net/tun.c  | 19 +++++++++++++++++++
> >   include/net/sock.h |  1 +
> >   2 files changed, 20 insertions(+)
> >
> > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > index ebd07ad82431..2c548bd20393 100644
> > --- a/drivers/net/tun.c
> > +++ b/drivers/net/tun.c
> > @@ -869,6 +869,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
> >   		tun_napi_init(tun, tfile, napi);
> >   	}
> >   
> > +	if (rtnl_dereference(tun->xdp_prog))
> > +		sock_set_flag(&tfile->sk, SOCK_XDP);
> > +
> >   	tun_set_real_num_queues(tun);
> >   
> >   	/* device is allowed to go away first, so no need to hold extra
> > @@ -1241,13 +1244,29 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
> >   		       struct netlink_ext_ack *extack)
> >   {
> >   	struct tun_struct *tun = netdev_priv(dev);
> > +	struct tun_file *tfile;
> >   	struct bpf_prog *old_prog;
> > +	int i;
> >   
> >   	old_prog = rtnl_dereference(tun->xdp_prog);
> >   	rcu_assign_pointer(tun->xdp_prog, prog);
> >   	if (old_prog)
> >   		bpf_prog_put(old_prog);
> >   
> > +	for (i = 0; i < tun->numqueues; i++) {
> > +		tfile = rtnl_dereference(tun->tfiles[i]);
> > +		if (prog)
> > +			sock_set_flag(&tfile->sk, SOCK_XDP);
> > +		else
> > +			sock_reset_flag(&tfile->sk, SOCK_XDP);
> > +	}
> > +	list_for_each_entry(tfile, &tun->disabled, next) {
> > +		if (prog)
> > +			sock_set_flag(&tfile->sk, SOCK_XDP);
> > +		else
> > +			sock_reset_flag(&tfile->sk, SOCK_XDP);
> > +	}
> > +
> >   	return 0;
> >   }
> >   
> > diff --git a/include/net/sock.h b/include/net/sock.h
> > index 433f45fc2d68..38cae35f6e16 100644
> > --- a/include/net/sock.h
> > +++ b/include/net/sock.h
> > @@ -800,6 +800,7 @@ enum sock_flags {
> >   	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
> >   	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
> >   	SOCK_TXTIME,
> > +	SOCK_XDP, /* XDP is attached */
> >   };
> >   
> >   #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
> > --
> > 2.17.1