[PATCH net-next 1/8] vhost: move get_rx_bufs to vhost.c

kbuild test robot
Wed, 04 Jul 2018 01:01:08 -0000

Hi Jason,

I love your patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:
https://github.com/0day-ci/linux/commits/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751
config: x86_64-randconfig-s0-07032254 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64

Note: the linux-review/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751
HEAD 01b902f1126212ea2597e6d09802bd9c4431bf82 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   drivers//vhost/net.c: In function
'handle_rx':
>> drivers//vhost/net.c:738:15: error: implicit declaration of function
'get_rx_bufs' [-Werror=implicit-function-declaration]
      headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx,
                  ^~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/get_rx_bufs +738 drivers//vhost/net.c

030881372 Jason Wang         2016-03-04  687
3a4d5c94e Michael S. Tsirkin 2010-01-14  688  /* Expects to be always run from
workqueue - which acts as
3a4d5c94e Michael S. Tsirkin 2010-01-14  689   * read-size critical section for
our kind of RCU. */
94249369e Jason Wang         2011-01-17  690  static void handle_rx(struct
vhost_net *net)
3a4d5c94e Michael S. Tsirkin 2010-01-14  691  {
81f95a558 Michael S. Tsirkin 2013-04-28  692  	struct vhost_net_virtqueue *nvq =
&net->vqs[VHOST_NET_VQ_RX];
81f95a558 Michael S. Tsirkin 2013-04-28  693  	struct vhost_virtqueue *vq =
&nvq->vq;
8dd014adf David Stevens      2010-07-27  694  	unsigned uninitialized_var(in),
log;
8dd014adf David Stevens      2010-07-27  695  	struct vhost_log *vq_log;
8dd014adf David Stevens      2010-07-27  696  	struct msghdr msg = {
8dd014adf David Stevens      2010-07-27  697  		.msg_name = NULL,
8dd014adf David Stevens      2010-07-27  698  		.msg_namelen = 0,
8dd014adf David Stevens      2010-07-27  699  		.msg_control = NULL, /* FIXME:
get and handle RX aux data. */
8dd014adf David Stevens      2010-07-27  700  		.msg_controllen = 0,
8dd014adf David Stevens      2010-07-27  701  		.msg_flags = MSG_DONTWAIT,
8dd014adf David Stevens      2010-07-27  702  	};
0960b6417 Jason Wang         2015-02-15  703  	struct virtio_net_hdr hdr = {
0960b6417 Jason Wang         2015-02-15  704  		.flags = 0,
0960b6417 Jason Wang         2015-02-15  705  		.gso_type =
VIRTIO_NET_HDR_GSO_NONE
8dd014adf David Stevens      2010-07-27  706  	};
8dd014adf David Stevens      2010-07-27  707  	size_t total_len = 0;
910a578f7 Michael S. Tsirkin 2012-10-24  708  	int err, mergeable;
f5a4941aa Jason Wang         2018-05-29  709  	s16 headcount;
8dd014adf David Stevens      2010-07-27  710  	size_t vhost_hlen, sock_hlen;
8dd014adf David Stevens      2010-07-27  711  	size_t vhost_len, sock_len;
2e26af79b Asias He           2013-05-07  712  	struct socket *sock;
ba7438aed Al Viro            2014-12-10  713  	struct iov_iter fixup;
0960b6417 Jason Wang         2015-02-15  714  	__virtio16 num_buffers;
db688c24e Paolo Abeni        2018-04-24  715  	int recv_pkts = 0;
8dd014adf David Stevens      2010-07-27  716
aaa3149bb Jason Wang         2018-03-26  717
mutex_lock_nested(&vq->mutex, 0);
2e26af79b Asias He           2013-05-07  718  	sock = vq->private_data;
2e26af79b Asias He           2013-05-07  719  	if (!sock)
2e26af79b Asias He           2013-05-07  720  		goto out;
6b1e6cc78 Jason Wang         2016-06-23  721
6b1e6cc78 Jason Wang         2016-06-23  722  	if (!vq_iotlb_prefetch(vq))
6b1e6cc78 Jason Wang         2016-06-23  723  		goto out;
6b1e6cc78 Jason Wang         2016-06-23  724
8ea8cf89e Michael S. Tsirkin 2011-05-20  725
vhost_disable_notify(&net->dev, vq);
8241a1e46 Jason Wang         2016-06-01  726  	vhost_net_disable_vq(net, vq);
2e26af79b Asias He           2013-05-07  727
81f95a558 Michael S. Tsirkin 2013-04-28  728  	vhost_hlen = nvq->vhost_hlen;
81f95a558 Michael S. Tsirkin 2013-04-28  729  	sock_hlen = nvq->sock_hlen;
8dd014adf David Stevens      2010-07-27  730
ea16c5143 Michael S. Tsirkin 2014-06-05  731  	vq_log =
unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
8dd014adf David Stevens      2010-07-27  732  		vq->log : NULL;
ea16c5143 Michael S. Tsirkin 2014-06-05  733  	mergeable = vhost_has_feature(vq,
VIRTIO_NET_F_MRG_RXBUF);
8dd014adf David Stevens      2010-07-27  734
030881372 Jason Wang         2016-03-04  735  	while ((sock_len =
vhost_net_rx_peek_head_len(net, sock->sk))) {
8dd014adf David Stevens      2010-07-27  736  		sock_len += sock_hlen;
8dd014adf David Stevens      2010-07-27  737  		vhost_len = sock_len +
vhost_hlen;
f5a4941aa Jason Wang         2018-05-29 @738  		headcount = get_rx_bufs(vq,
vq->heads + nvq->done_idx,
f5a4941aa Jason Wang         2018-05-29  739  					vhost_len, &in, vq_log,
&log,
94249369e Jason Wang         2011-01-17  740  					likely(mergeable) ?
UIO_MAXIOV : 1);
8dd014adf David Stevens      2010-07-27  741  		/* On error, stop handling until
the next kick. */
8dd014adf David Stevens      2010-07-27  742  		if (unlikely(headcount < 0))
8241a1e46 Jason Wang         2016-06-01  743  			goto out;
8dd014adf David Stevens      2010-07-27  744  		/* OK, now we need to know about
added descriptors. */
8dd014adf David Stevens      2010-07-27  745  		if (!headcount) {
8ea8cf89e Michael S. Tsirkin 2011-05-20  746  			if
(unlikely(vhost_enable_notify(&net->dev, vq))) {
8dd014adf David Stevens      2010-07-27  747  				/* They have slipped one in as
we were
8dd014adf David Stevens      2010-07-27  748  				 * doing that: check again. */
8ea8cf89e Michael S. Tsirkin 2011-05-20  749
vhost_disable_notify(&net->dev, vq);
8dd014adf David Stevens      2010-07-27  750  				continue;
8dd014adf David Stevens      2010-07-27  751  			}
8dd014adf David Stevens      2010-07-27  752  			/* Nothing new?  Wait for
eventfd to tell us
8dd014adf David Stevens      2010-07-27  753  			 * they refilled. */
8241a1e46 Jason Wang         2016-06-01  754  			goto out;
8dd014adf David Stevens      2010-07-27  755  		}
5990a3051 Jason Wang         2018-01-04  756  		if (nvq->rx_ring)
6e474083f Wei Xu             2017-12-01  757  			msg.msg_control =
vhost_net_buf_consume(&nvq->rxq);
6e474083f Wei Xu             2017-12-01  758  		/* On overrun, truncate and
discard */
6e474083f Wei Xu             2017-12-01  759  		if (unlikely(headcount >
UIO_MAXIOV)) {
6e474083f Wei Xu             2017-12-01  760
iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
6e474083f Wei Xu             2017-12-01  761  			err =
sock->ops->recvmsg(sock, &msg,
6e474083f Wei Xu             2017-12-01  762  						 1, MSG_DONTWAIT |
MSG_TRUNC);
6e474083f Wei Xu             2017-12-01  763  			pr_debug("Discarded rx
packet: len %zd\n", sock_len);
6e474083f Wei Xu             2017-12-01  764  			continue;
6e474083f Wei Xu             2017-12-01  765  		}
8dd014adf David Stevens      2010-07-27  766  		/* We don't need to be
notified again. */
ba7438aed Al Viro            2014-12-10  767  		iov_iter_init(&msg.msg_iter,
READ, vq->iov, in, vhost_len);
ba7438aed Al Viro            2014-12-10  768  		fixup = msg.msg_iter;
ba7438aed Al Viro            2014-12-10  769  		if (unlikely((vhost_hlen))) {
ba7438aed Al Viro            2014-12-10  770  			/* We will supply the header
ourselves
ba7438aed Al Viro            2014-12-10  771  			 * TODO: support TSO.
ba7438aed Al Viro            2014-12-10  772  			 */
ba7438aed Al Viro            2014-12-10  773
iov_iter_advance(&msg.msg_iter, vhost_hlen);
ba7438aed Al Viro            2014-12-10  774  		}
1b7841404 Ying Xue           2015-03-02  775  		err =
sock->ops->recvmsg(sock, &msg,
8dd014adf David Stevens      2010-07-27  776  					 sock_len, MSG_DONTWAIT |
MSG_TRUNC);
8dd014adf David Stevens      2010-07-27  777  		/* Userspace might have consumed
the packet meanwhile:
8dd014adf David Stevens      2010-07-27  778  		 * it's not supposed to do
this usually, but might be hard
8dd014adf David Stevens      2010-07-27  779  		 * to prevent. Discard data we
got (if any) and keep going. */
8dd014adf David Stevens      2010-07-27  780  		if (unlikely(err != sock_len)) {
8dd014adf David Stevens      2010-07-27  781  			pr_debug("Discarded rx
packet: "
8dd014adf David Stevens      2010-07-27  782  				 " len %d, expected
%zd\n", err, sock_len);
8dd014adf David Stevens      2010-07-27  783  			vhost_discard_vq_desc(vq,
headcount);
8dd014adf David Stevens      2010-07-27  784  			continue;
8dd014adf David Stevens      2010-07-27  785  		}
ba7438aed Al Viro            2014-12-10  786  		/* Supply virtio_net_hdr if
VHOST_NET_F_VIRTIO_NET_HDR */
4c5a84421 Michael S. Tsirkin 2015-02-25  787  		if (unlikely(vhost_hlen)) {
4c5a84421 Michael S. Tsirkin 2015-02-25  788  			if (copy_to_iter(&hdr,
sizeof(hdr),
4c5a84421 Michael S. Tsirkin 2015-02-25  789  					 &fixup) != sizeof(hdr))
{
4c5a84421 Michael S. Tsirkin 2015-02-25  790  				vq_err(vq, "Unable to
write vnet_hdr "
4c5a84421 Michael S. Tsirkin 2015-02-25  791  				       "at addr
%p\n", vq->iov->iov_base);
8241a1e46 Jason Wang         2016-06-01  792  				goto out;
8dd014adf David Stevens      2010-07-27  793  			}
4c5a84421 Michael S. Tsirkin 2015-02-25  794  		} else {
4c5a84421 Michael S. Tsirkin 2015-02-25  795  			/* Header came from socket;
we'll need to patch
4c5a84421 Michael S. Tsirkin 2015-02-25  796  			 * ->num_buffers over if
VIRTIO_NET_F_MRG_RXBUF
4c5a84421 Michael S. Tsirkin 2015-02-25  797  			 */
4c5a84421 Michael S. Tsirkin 2015-02-25  798  			iov_iter_advance(&fixup,
sizeof(hdr));
4c5a84421 Michael S. Tsirkin 2015-02-25  799  		}
8dd014adf David Stevens      2010-07-27  800  		/* TODO: Should check and handle
checksum. */
5201aa49b Michael S. Tsirkin 2015-02-03  801
0960b6417 Jason Wang         2015-02-15  802  		num_buffers = cpu_to_vhost16(vq,
headcount);
cfbdab951 Jason Wang         2011-01-17  803  		if (likely(mergeable) &&
0d79a493e Michael S. Tsirkin 2015-02-25  804
copy_to_iter(&num_buffers, sizeof num_buffers,
0d79a493e Michael S. Tsirkin 2015-02-25  805  				 &fixup) != sizeof
num_buffers) {
8dd014adf David Stevens      2010-07-27  806  			vq_err(vq, "Failed
num_buffers write");
8dd014adf David Stevens      2010-07-27  807  			vhost_discard_vq_desc(vq,
headcount);
8241a1e46 Jason Wang         2016-06-01  808  			goto out;
8dd014adf David Stevens      2010-07-27  809  		}
f5a4941aa Jason Wang         2018-05-29  810  		nvq->done_idx += headcount;
f5a4941aa Jason Wang         2018-05-29  811  		if (nvq->done_idx >
VHOST_RX_BATCH)
f5a4941aa Jason Wang         2018-05-29  812  			vhost_rx_signal_used(nvq);
8dd014adf David Stevens      2010-07-27  813  		if (unlikely(vq_log))
8dd014adf David Stevens      2010-07-27  814  			vhost_log_write(vq, vq_log,
log, vhost_len);
8dd014adf David Stevens      2010-07-27  815  		total_len += vhost_len;
db688c24e Paolo Abeni        2018-04-24  816  		if (unlikely(total_len >=
VHOST_NET_WEIGHT) ||
db688c24e Paolo Abeni        2018-04-24  817  		    unlikely(++recv_pkts >=
VHOST_NET_PKT_WEIGHT)) {
8dd014adf David Stevens      2010-07-27  818
vhost_poll_queue(&vq->poll);
8241a1e46 Jason Wang         2016-06-01  819  			goto out;
8dd014adf David Stevens      2010-07-27  820  		}
8dd014adf David Stevens      2010-07-27  821  	}
8241a1e46 Jason Wang         2016-06-01  822  	vhost_net_enable_vq(net, vq);
2e26af79b Asias He           2013-05-07  823  out:
f5a4941aa Jason Wang         2018-05-29  824  	vhost_rx_signal_used(nvq);
8dd014adf David Stevens      2010-07-27  825  	mutex_unlock(&vq->mutex);
8dd014adf David Stevens      2010-07-27  826  }
8dd014adf David Stevens      2010-07-27  827

:::::: The code at line 738 was first introduced by commit
:::::: f5a4941aa6d190e676065e8f4ed35999f52a01c3 vhost_net: flush batched heads
before trying to busy polling

:::::: TO: Jason Wang <jasowang at redhat.com>
:::::: CC: David S. Miller <davem at davemloft.net>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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