From: Andrey Smetanin asmetanin@yandex-team.ru
[ Upstream commit 1f5d2e3bab16369d5d4b4020a25db4ab1f4f082c ]
Fix possible virtqueue used buffers leak and corresponding stuck in case of temporary -EIO from sendmsg() which is produced by tun driver while backend device is not up.
In case of no-retriable error and zcopy do not revert upend_idx to pass packet data (that is update used_idx in corresponding vhost_zerocopy_signal_used()) as if packet data has been transferred successfully.
v2: set vq->heads[ubuf->desc].len equal to VHOST_DMA_DONE_LEN in case of fake successful transmit.
Signed-off-by: Andrey Smetanin asmetanin@yandex-team.ru Message-Id: 20230424204411.24888-1-asmetanin@yandex-team.ru Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Andrey Smetanin asmetanin@yandex-team.ru Acked-by: Jason Wang jasowang@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vhost/net.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 07181cd8d52e6..ae2273196b0c9 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -935,13 +935,18 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { + bool retry = err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS; + if (zcopy_used) { if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) vhost_net_ubuf_put(ubufs); - nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) - % UIO_MAXIOV; + if (retry) + nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) + % UIO_MAXIOV; + else + vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN; } - if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { + if (retry) { vhost_discard_vq_desc(vq, 1); vhost_net_enable_vq(net, vq); break;