VHOST_NET_VQ_MAX = 2,
};
-enum vhost_net_poll_state {
- VHOST_NET_POLL_DISABLED = 0,
- VHOST_NET_POLL_STARTED = 1,
- VHOST_NET_POLL_STOPPED = 2,
+struct vhost_ubuf_ref {
+ struct kref kref;
+ wait_queue_head_t wait;
+ struct vhost_virtqueue *vq;
+};
+
+struct vhost_net_virtqueue {
+ struct vhost_virtqueue vq;
+ /* hdr is used to store the virtio header.
+ * Since each iovec has >= 1 byte length, we never need more than
+ * header length entries to store the header. */
+ struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
+ size_t vhost_hlen;
+ size_t sock_hlen;
+ /* vhost zerocopy support fields below: */
+ /* last used idx for outstanding DMA zerocopy buffers */
+ int upend_idx;
+ /* first used idx for DMA done zerocopy buffers */
+ int done_idx;
+ /* an array of userspace buffers info */
+ struct ubuf_info *ubuf_info;
+ /* Reference counting for outstanding ubufs.
+ * Protected by vq mutex. Writers must also take device mutex. */
+ struct vhost_ubuf_ref *ubufs;
};
struct vhost_net {
struct vhost_dev dev;
- struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
+ struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
struct vhost_poll poll[VHOST_NET_VQ_MAX];
- /* Tells us whether we are polling a socket for TX.
- * We only do this when socket buffer fills up.
- * Protected by tx vq lock. */
- enum vhost_net_poll_state tx_poll_state;
/* Number of TX recently submitted.
* Protected by tx vq lock. */
unsigned tx_packets;
bool tx_flush;
};
+static unsigned vhost_zcopy_mask __read_mostly;
+
+void vhost_enable_zcopy(int vq)
+{
+ vhost_zcopy_mask |= 0x1 << vq;
+}
+
+static void vhost_zerocopy_done_signal(struct kref *kref)
+{
+ struct vhost_ubuf_ref *ubufs = container_of(kref, struct vhost_ubuf_ref,
+ kref);
+ wake_up(&ubufs->wait);
+}
+
+struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *vq,
+ bool zcopy)
+{
+ struct vhost_ubuf_ref *ubufs;
+ /* No zero copy backend? Nothing to count. */
+ if (!zcopy)
+ return NULL;
+ ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
+ if (!ubufs)
+ return ERR_PTR(-ENOMEM);
+ kref_init(&ubufs->kref);
+ init_waitqueue_head(&ubufs->wait);
+ ubufs->vq = vq;
+ return ubufs;
+}
+
+void vhost_ubuf_put(struct vhost_ubuf_ref *ubufs)
+{
+ kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+}
+
+void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs)
+{
+ kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+ wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
+ kfree(ubufs);
+}
+
+int vhost_net_set_ubuf_info(struct vhost_net *n)
+{
+ bool zcopy;
+ int i;
+
+ for (i = 0; i < n->dev.nvqs; ++i) {
+ zcopy = vhost_zcopy_mask & (0x1 << i);
+ if (!zcopy)
+ continue;
+ n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
+ UIO_MAXIOV, GFP_KERNEL);
+ if (!n->vqs[i].ubuf_info)
+ goto err;
+ }
+ return 0;
+
+err:
+ while (i--) {
+ zcopy = vhost_zcopy_mask & (0x1 << i);
+ if (!zcopy)
+ continue;
+ kfree(n->vqs[i].ubuf_info);
+ }
+ return -ENOMEM;
+}
+
+void vhost_net_vq_reset(struct vhost_net *n)
+{
+ int i;
+
+ for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
+ n->vqs[i].done_idx = 0;
+ n->vqs[i].upend_idx = 0;
+ n->vqs[i].ubufs = NULL;
+ kfree(n->vqs[i].ubuf_info);
+ n->vqs[i].ubuf_info = NULL;
+ n->vqs[i].vhost_hlen = 0;
+ n->vqs[i].sock_hlen = 0;
+ }
+
+}
+
static void vhost_net_tx_packet(struct vhost_net *net)
{
++net->tx_packets;
}
}
-/* Caller must have TX VQ lock */
-static void tx_poll_stop(struct vhost_net *net)
-{
- if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
- return;
- vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
- net->tx_poll_state = VHOST_NET_POLL_STOPPED;
-}
-
-/* Caller must have TX VQ lock */
-static int tx_poll_start(struct vhost_net *net, struct socket *sock)
-{
- int ret;
-
- if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
- return 0;
- ret = vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
- if (!ret)
- net->tx_poll_state = VHOST_NET_POLL_STARTED;
- return ret;
-}
-
/* In case of DMA done not in order in lower device driver for some reason.
* upend_idx is used to track end of used idx, done_idx is used to track head
* of used idx. Once lower device DMA done contiguously, we will signal KVM
static int vhost_zerocopy_signal_used(struct vhost_net *net,
struct vhost_virtqueue *vq)
{
+ struct vhost_net_virtqueue *nvq =
+ container_of(vq, struct vhost_net_virtqueue, vq);
int i;
int j = 0;
- for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
+ for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
vhost_net_tx_err(net);
if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
break;
}
if (j)
- vq->done_idx = i;
+ nvq->done_idx = i;
return j;
}
* read-size critical section for our kind of RCU. */
static void handle_tx(struct vhost_net *net)
{
- struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
+ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
+ struct vhost_virtqueue *vq = &nvq->vq;
unsigned out, in, s;
int head;
struct msghdr msg = {
.msg_flags = MSG_DONTWAIT,
};
size_t len, total_len = 0;
- int err, wmem;
+ int err;
size_t hdr_size;
struct socket *sock;
struct vhost_ubuf_ref *uninitialized_var(ubufs);
if (!sock)
return;
- wmem = atomic_read(&sock->sk->sk_wmem_alloc);
- if (wmem >= sock->sk->sk_sndbuf) {
- mutex_lock(&vq->mutex);
- tx_poll_start(net, sock);
- mutex_unlock(&vq->mutex);
- return;
- }
-
mutex_lock(&vq->mutex);
vhost_disable_notify(&net->dev, vq);
- if (wmem < sock->sk->sk_sndbuf / 2)
- tx_poll_stop(net);
- hdr_size = vq->vhost_hlen;
- zcopy = vq->ubufs;
+ hdr_size = nvq->vhost_hlen;
+ zcopy = nvq->ubufs;
for (;;) {
/* Release DMAs done buffers first */
if (head == vq->num) {
int num_pends;
- wmem = atomic_read(&sock->sk->sk_wmem_alloc);
- if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
- tx_poll_start(net, sock);
- set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
- break;
- }
/* If more outstanding DMAs, queue the work.
* Handle upend_idx wrap around
*/
- num_pends = likely(vq->upend_idx >= vq->done_idx) ?
- (vq->upend_idx - vq->done_idx) :
- (vq->upend_idx + UIO_MAXIOV - vq->done_idx);
- if (unlikely(num_pends > VHOST_MAX_PEND)) {
- tx_poll_start(net, sock);
- set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
+ num_pends = likely(nvq->upend_idx >= nvq->done_idx) ?
+ (nvq->upend_idx - nvq->done_idx) :
+ (nvq->upend_idx + UIO_MAXIOV -
+ nvq->done_idx);
+ if (unlikely(num_pends > VHOST_MAX_PEND))
break;
- }
if (unlikely(vhost_enable_notify(&net->dev, vq))) {
vhost_disable_notify(&net->dev, vq);
continue;
break;
}
/* Skip header. TODO: support TSO. */
- s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
+ s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out);
msg.msg_iovlen = out;
len = iov_length(vq->iov, out);
/* Sanity check */
if (!len) {
vq_err(vq, "Unexpected header len for TX: "
"%zd expected %zd\n",
- iov_length(vq->hdr, s), hdr_size);
+ iov_length(nvq->hdr, s), hdr_size);
break;
}
zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
- vq->upend_idx != vq->done_idx);
+ nvq->upend_idx != nvq->done_idx);
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
- vq->heads[vq->upend_idx].id = head;
+ vq->heads[nvq->upend_idx].id = head;
if (!vhost_net_tx_select_zcopy(net) ||
len < VHOST_GOODCOPY_LEN) {
/* copy don't need to wait for DMA done */
- vq->heads[vq->upend_idx].len =
+ vq->heads[nvq->upend_idx].len =
VHOST_DMA_DONE_LEN;
msg.msg_control = NULL;
msg.msg_controllen = 0;
ubufs = NULL;
} else {
struct ubuf_info *ubuf;
- ubuf = vq->ubuf_info + vq->upend_idx;
+ ubuf = nvq->ubuf_info + nvq->upend_idx;
- vq->heads[vq->upend_idx].len =
+ vq->heads[nvq->upend_idx].len =
VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
- ubuf->ctx = vq->ubufs;
- ubuf->desc = vq->upend_idx;
+ ubuf->ctx = nvq->ubufs;
+ ubuf->desc = nvq->upend_idx;
msg.msg_control = ubuf;
msg.msg_controllen = sizeof(ubuf);
- ubufs = vq->ubufs;
+ ubufs = nvq->ubufs;
kref_get(&ubufs->kref);
}
- vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
+ nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
}
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(NULL, sock, &msg, len);
if (zcopy_used) {
if (ubufs)
vhost_ubuf_put(ubufs);
- vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
- UIO_MAXIOV;
+ nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
+ % UIO_MAXIOV;
}
vhost_discard_vq_desc(vq, 1);
- if (err == -EAGAIN || err == -ENOBUFS)
- tx_poll_start(net, sock);
break;
}
if (err != len)
* read-size critical section for our kind of RCU. */
static void handle_rx(struct vhost_net *net)
{
- struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+ struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
+ struct vhost_virtqueue *vq = &nvq->vq;
unsigned uninitialized_var(in), log;
struct vhost_log *vq_log;
struct msghdr msg = {
mutex_lock(&vq->mutex);
vhost_disable_notify(&net->dev, vq);
- vhost_hlen = vq->vhost_hlen;
- sock_hlen = vq->sock_hlen;
+ vhost_hlen = nvq->vhost_hlen;
+ sock_hlen = nvq->sock_hlen;
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
/* 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);
+ move_iovec_hdr(vq->iov, nvq->hdr, vhost_hlen, in);
else
/* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
* needed because recvmsg can modify msg_iov. */
- copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
+ copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in);
msg.msg_iovlen = in;
err = sock->ops->recvmsg(NULL, sock, &msg,
sock_len, MSG_DONTWAIT | MSG_TRUNC);
continue;
}
if (unlikely(vhost_hlen) &&
- memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
+ memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0,
vhost_hlen)) {
vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
vq->iov->iov_base);
}
/* TODO: Should check and handle checksum. */
if (likely(mergeable) &&
- memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
+ memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount,
offsetof(typeof(hdr), num_buffers),
sizeof hdr.num_buffers)) {
vq_err(vq, "Failed num_buffers write");
{
struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
struct vhost_dev *dev;
- int r;
+ struct vhost_virtqueue **vqs;
+ int r, i;
if (!n)
return -ENOMEM;
+ vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
+ if (!vqs) {
+ kfree(n);
+ return -ENOMEM;
+ }
dev = &n->dev;
- n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
- n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
- r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
+ vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
+ vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
+ n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
+ n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
+ for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
+ n->vqs[i].ubufs = NULL;
+ n->vqs[i].ubuf_info = NULL;
+ n->vqs[i].upend_idx = 0;
+ n->vqs[i].done_idx = 0;
+ n->vqs[i].vhost_hlen = 0;
+ n->vqs[i].sock_hlen = 0;
+ }
+ r = vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
if (r < 0) {
kfree(n);
+ kfree(vqs);
return r;
}
vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
- n->tx_poll_state = VHOST_NET_POLL_DISABLED;
f->private_data = n;
static void vhost_net_disable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
+ struct vhost_net_virtqueue *nvq =
+ container_of(vq, struct vhost_net_virtqueue, vq);
+ struct vhost_poll *poll = n->poll + (nvq - n->vqs);
if (!vq->private_data)
return;
- if (vq == n->vqs + VHOST_NET_VQ_TX) {
- tx_poll_stop(n);
- n->tx_poll_state = VHOST_NET_POLL_DISABLED;
- } else
- vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
+ vhost_poll_stop(poll);
}
static int vhost_net_enable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
+ struct vhost_net_virtqueue *nvq =
+ container_of(vq, struct vhost_net_virtqueue, vq);
+ struct vhost_poll *poll = n->poll + (nvq - n->vqs);
struct socket *sock;
- int ret;
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (!sock)
return 0;
- if (vq == n->vqs + VHOST_NET_VQ_TX) {
- n->tx_poll_state = VHOST_NET_POLL_STOPPED;
- ret = tx_poll_start(n, sock);
- } else
- ret = vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
- return ret;
+ return vhost_poll_start(poll, sock->file);
}
static struct socket *vhost_net_stop_vq(struct vhost_net *n,
static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
struct socket **rx_sock)
{
- *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
- *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
+ *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
+ *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
}
static void vhost_net_flush_vq(struct vhost_net *n, int index)
{
vhost_poll_flush(n->poll + index);
- vhost_poll_flush(&n->dev.vqs[index].poll);
+ vhost_poll_flush(&n->vqs[index].vq.poll);
}
static void vhost_net_flush(struct vhost_net *n)
{
vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
- if (n->dev.vqs[VHOST_NET_VQ_TX].ubufs) {
- mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
+ mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
n->tx_flush = true;
- mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
/* Wait for all lower device DMAs done. */
- vhost_ubuf_put_and_wait(n->dev.vqs[VHOST_NET_VQ_TX].ubufs);
- mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ vhost_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
+ mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
n->tx_flush = false;
- kref_init(&n->dev.vqs[VHOST_NET_VQ_TX].ubufs->kref);
- mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+ kref_init(&n->vqs[VHOST_NET_VQ_TX].ubufs->kref);
+ mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
}
}
vhost_net_flush(n);
vhost_dev_stop(&n->dev);
vhost_dev_cleanup(&n->dev, false);
+ vhost_net_vq_reset(n);
if (tx_sock)
fput(tx_sock->file);
if (rx_sock)
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
+ kfree(n->dev.vqs);
kfree(n);
return 0;
}
{
struct socket *sock, *oldsock;
struct vhost_virtqueue *vq;
+ struct vhost_net_virtqueue *nvq;
struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
int r;
r = -ENOBUFS;
goto err;
}
- vq = n->vqs + index;
+ vq = &n->vqs[index].vq;
+ nvq = &n->vqs[index];
mutex_lock(&vq->mutex);
/* Verify that ring has been setup correctly. */
if (r)
goto err_used;
- oldubufs = vq->ubufs;
- vq->ubufs = ubufs;
+ oldubufs = nvq->ubufs;
+ nvq->ubufs = ubufs;
n->tx_packets = 0;
n->tx_zcopy_err = 0;
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
err = vhost_dev_reset_owner(&n->dev);
+ vhost_net_vq_reset(n);
done:
mutex_unlock(&n->dev.mutex);
if (tx_sock)
n->dev.acked_features = features;
smp_wmb();
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
- mutex_lock(&n->vqs[i].mutex);
+ mutex_lock(&n->vqs[i].vq.mutex);
n->vqs[i].vhost_hlen = vhost_hlen;
n->vqs[i].sock_hlen = sock_hlen;
- mutex_unlock(&n->vqs[i].mutex);
+ mutex_unlock(&n->vqs[i].vq.mutex);
}
vhost_net_flush(n);
mutex_unlock(&n->dev.mutex);
return vhost_net_reset_owner(n);
default:
mutex_lock(&n->dev.mutex);
+ if (ioctl == VHOST_SET_OWNER) {
+ r = vhost_net_set_ubuf_info(n);
+ if (r)
+ goto out;
+ }
r = vhost_dev_ioctl(&n->dev, ioctl, argp);
if (r == -ENOIOCTLCMD)
r = vhost_vring_ioctl(&n->dev, ioctl, argp);
else
vhost_net_flush(n);
+out:
mutex_unlock(&n->dev.mutex);
return r;
}
projects / ~andy / linux / blobdiff