From: Yunjian Wang wangyunjian@huawei.com
mainline inclusion from mainline-5.12-rc1 commit dc9c9e72ff3ba01ae63e6263ac26234ba1869cd7 category: bugfix bugzilla: NA CVE: NA
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Currently the driver doesn't drop a packet which can't be sent by tun (e.g bad packet). In this case, the driver will always process the same packet lead to the tx queue stuck.
To fix this issue: 1. in the case of persistent failure (e.g bad packet), the driver can skip this descriptor by ignoring the error. 2. in the case of transient failure (e.g -ENOBUFS, -EAGAIN and -ENOMEM), the driver schedules the worker to try again.
Signed-off-by: Yunjian Wang wangyunjian@huawei.com Acked-by: Jason Wang jasowang@redhat.com Acked-by: Willem de Bruijn willemb@google.com Acked-by: Michael S. Tsirkin mst@redhat.com Link: https://lore.kernel.org/r/1610685980-38608-1-git-send-email-wangyunjian@huaw... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/vhost/net.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 0c7bbc92b22a9..1d99f5c443eeb 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -580,14 +580,15 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock) else msg.msg_flags &= ~MSG_MORE;
- /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { - vhost_discard_vq_desc(vq, 1); - vhost_net_enable_vq(net, vq); - break; - } - if (err != len) + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { + vhost_discard_vq_desc(vq, 1); + vhost_net_enable_vq(net, vq); + break; + } + pr_debug("Fail to send packet: err %d", err); + } else if (unlikely(err != len)) pr_debug("Truncated TX packet: len %d != %zd\n", err, len); if (++nvq->done_idx >= VHOST_NET_BATCH) @@ -670,7 +671,6 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) msg.msg_flags &= ~MSG_MORE; }
- /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { @@ -679,11 +679,13 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; } - vhost_discard_vq_desc(vq, 1); - vhost_net_enable_vq(net, vq); - break; - } - if (err != len) + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { + vhost_discard_vq_desc(vq, 1); + vhost_net_enable_vq(net, vq); + break; + } + pr_debug("Fail to send packet: err %d", err); + } else if (unlikely(err != len)) pr_debug("Truncated TX packet: " " len %d != %zd\n", err, len); if (!zcopy_used)