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path: root/drivers/vhost/net.c
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Diffstat (limited to 'drivers/vhost/net.c')
-rw-r--r--drivers/vhost/net.c237
1 files changed, 228 insertions, 9 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index d395b59289a..f13e56babe4 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -74,6 +74,22 @@ static int move_iovec_hdr(struct iovec *from, struct iovec *to,
}
return seg;
}
+/* Copy iovec entries for len bytes from iovec. */
+static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
+ size_t len, int iovcount)
+{
+ int seg = 0;
+ size_t size;
+ while (len && seg < iovcount) {
+ size = min(from->iov_len, len);
+ to->iov_base = from->iov_base;
+ to->iov_len = size;
+ len -= size;
+ ++from;
+ ++to;
+ ++seg;
+ }
+}
/* Caller must have TX VQ lock */
static void tx_poll_stop(struct vhost_net *net)
@@ -129,7 +145,7 @@ static void handle_tx(struct vhost_net *net)
if (wmem < sock->sk->sk_sndbuf / 2)
tx_poll_stop(net);
- hdr_size = vq->hdr_size;
+ hdr_size = vq->vhost_hlen;
for (;;) {
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
@@ -172,7 +188,7 @@ static void handle_tx(struct vhost_net *net)
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(NULL, sock, &msg, len);
if (unlikely(err < 0)) {
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
tx_poll_start(net, sock);
break;
}
@@ -191,9 +207,82 @@ static void handle_tx(struct vhost_net *net)
unuse_mm(net->dev.mm);
}
+static int peek_head_len(struct sock *sk)
+{
+ struct sk_buff *head;
+ int len = 0;
+
+ lock_sock(sk);
+ head = skb_peek(&sk->sk_receive_queue);
+ if (head)
+ len = head->len;
+ release_sock(sk);
+ return len;
+}
+
+/* This is a multi-buffer version of vhost_get_desc, that works if
+ * vq has read descriptors only.
+ * @vq - the relevant virtqueue
+ * @datalen - data length we'll be reading
+ * @iovcount - returned count of io vectors we fill
+ * @log - vhost log
+ * @log_num - log offset
+ * returns number of buffer heads allocated, negative on error
+ */
+static int get_rx_bufs(struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads,
+ int datalen,
+ unsigned *iovcount,
+ struct vhost_log *log,
+ unsigned *log_num)
+{
+ unsigned int out, in;
+ int seg = 0;
+ int headcount = 0;
+ unsigned d;
+ int r, nlogs = 0;
+
+ while (datalen > 0) {
+ if (unlikely(headcount >= VHOST_NET_MAX_SG)) {
+ r = -ENOBUFS;
+ goto err;
+ }
+ d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
+ ARRAY_SIZE(vq->iov) - seg, &out,
+ &in, log, log_num);
+ if (d == vq->num) {
+ r = 0;
+ goto err;
+ }
+ if (unlikely(out || in <= 0)) {
+ vq_err(vq, "unexpected descriptor format for RX: "
+ "out %d, in %d\n", out, in);
+ r = -EINVAL;
+ goto err;
+ }
+ if (unlikely(log)) {
+ nlogs += *log_num;
+ log += *log_num;
+ }
+ heads[headcount].id = d;
+ heads[headcount].len = iov_length(vq->iov + seg, in);
+ datalen -= heads[headcount].len;
+ ++headcount;
+ seg += in;
+ }
+ heads[headcount - 1].len += datalen;
+ *iovcount = seg;
+ if (unlikely(log))
+ *log_num = nlogs;
+ return headcount;
+err:
+ vhost_discard_vq_desc(vq, headcount);
+ return r;
+}
+
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
-static void handle_rx(struct vhost_net *net)
+static void handle_rx_big(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
unsigned out, in, log, s;
@@ -223,7 +312,7 @@ static void handle_rx(struct vhost_net *net)
use_mm(net->dev.mm);
mutex_lock(&vq->mutex);
vhost_disable_notify(vq);
- hdr_size = vq->hdr_size;
+ hdr_size = vq->vhost_hlen;
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
@@ -270,14 +359,14 @@ static void handle_rx(struct vhost_net *net)
len, MSG_DONTWAIT | MSG_TRUNC);
/* TODO: Check specific error and bomb out unless EAGAIN? */
if (err < 0) {
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
break;
}
/* TODO: Should check and handle checksum. */
if (err > len) {
pr_debug("Discarded truncated rx packet: "
" len %d > %zd\n", err, len);
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
continue;
}
len = err;
@@ -302,6 +391,123 @@ static void handle_rx(struct vhost_net *net)
unuse_mm(net->dev.mm);
}
+/* Expects to be always run from workqueue - which acts as
+ * read-size critical section for our kind of RCU. */
+static void handle_rx_mergeable(struct vhost_net *net)
+{
+ struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+ unsigned uninitialized_var(in), log;
+ struct vhost_log *vq_log;
+ struct msghdr msg = {
+ .msg_name = NULL,
+ .msg_namelen = 0,
+ .msg_control = NULL, /* FIXME: get and handle RX aux data. */
+ .msg_controllen = 0,
+ .msg_iov = vq->iov,
+ .msg_flags = MSG_DONTWAIT,
+ };
+
+ struct virtio_net_hdr_mrg_rxbuf hdr = {
+ .hdr.flags = 0,
+ .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
+ };
+
+ size_t total_len = 0;
+ int err, headcount;
+ size_t vhost_hlen, sock_hlen;
+ size_t vhost_len, sock_len;
+ struct socket *sock = rcu_dereference(vq->private_data);
+ if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
+ return;
+
+ use_mm(net->dev.mm);
+ mutex_lock(&vq->mutex);
+ vhost_disable_notify(vq);
+ vhost_hlen = vq->vhost_hlen;
+ sock_hlen = vq->sock_hlen;
+
+ vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
+ vq->log : NULL;
+
+ while ((sock_len = peek_head_len(sock->sk))) {
+ sock_len += sock_hlen;
+ vhost_len = sock_len + vhost_hlen;
+ headcount = get_rx_bufs(vq, vq->heads, vhost_len,
+ &in, vq_log, &log);
+ /* On error, stop handling until the next kick. */
+ if (unlikely(headcount < 0))
+ break;
+ /* OK, now we need to know about added descriptors. */
+ if (!headcount) {
+ if (unlikely(vhost_enable_notify(vq))) {
+ /* They have slipped one in as we were
+ * doing that: check again. */
+ vhost_disable_notify(vq);
+ continue;
+ }
+ /* Nothing new? Wait for eventfd to tell us
+ * they refilled. */
+ break;
+ }
+ /* We don't need to be notified again. */
+ if (unlikely((vhost_hlen)))
+ /* Skip header. TODO: support TSO. */
+ move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
+ else
+ /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
+ * needed because sendmsg can modify msg_iov. */
+ copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
+ msg.msg_iovlen = in;
+ err = sock->ops->recvmsg(NULL, sock, &msg,
+ sock_len, MSG_DONTWAIT | MSG_TRUNC);
+ /* Userspace might have consumed the packet meanwhile:
+ * it's not supposed to do this usually, but might be hard
+ * to prevent. Discard data we got (if any) and keep going. */
+ if (unlikely(err != sock_len)) {
+ pr_debug("Discarded rx packet: "
+ " len %d, expected %zd\n", err, sock_len);
+ vhost_discard_vq_desc(vq, headcount);
+ continue;
+ }
+ if (unlikely(vhost_hlen) &&
+ memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
+ vhost_hlen)) {
+ vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
+ vq->iov->iov_base);
+ break;
+ }
+ /* TODO: Should check and handle checksum. */
+ if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF) &&
+ memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
+ offsetof(typeof(hdr), num_buffers),
+ sizeof hdr.num_buffers)) {
+ vq_err(vq, "Failed num_buffers write");
+ vhost_discard_vq_desc(vq, headcount);
+ break;
+ }
+ vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
+ headcount);
+ if (unlikely(vq_log))
+ vhost_log_write(vq, vq_log, log, vhost_len);
+ total_len += vhost_len;
+ if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
+ vhost_poll_queue(&vq->poll);
+ break;
+ }
+ }
+
+ mutex_unlock(&vq->mutex);
+ unuse_mm(net->dev.mm);
+}
+
+static void handle_rx(struct vhost_net *net)
+{
+ if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF))
+ handle_rx_mergeable(net);
+ else
+ handle_rx_big(net);
+}
+
static void handle_tx_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
@@ -577,9 +783,21 @@ done:
static int vhost_net_set_features(struct vhost_net *n, u64 features)
{
- size_t hdr_size = features & (1 << VHOST_NET_F_VIRTIO_NET_HDR) ?
- sizeof(struct virtio_net_hdr) : 0;
+ size_t vhost_hlen, sock_hlen, hdr_len;
int i;
+
+ hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
+ sizeof(struct virtio_net_hdr_mrg_rxbuf) :
+ sizeof(struct virtio_net_hdr);
+ if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
+ /* vhost provides vnet_hdr */
+ vhost_hlen = hdr_len;
+ sock_hlen = 0;
+ } else {
+ /* socket provides vnet_hdr */
+ vhost_hlen = 0;
+ sock_hlen = hdr_len;
+ }
mutex_lock(&n->dev.mutex);
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&n->dev)) {
@@ -590,7 +808,8 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
smp_wmb();
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
mutex_lock(&n->vqs[i].mutex);
- n->vqs[i].hdr_size = hdr_size;
+ n->vqs[i].vhost_hlen = vhost_hlen;
+ n->vqs[i].sock_hlen = sock_hlen;
mutex_unlock(&n->vqs[i].mutex);
}
vhost_net_flush(n);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-29 00:08:45 +0000