diff options
Diffstat (limited to 'drivers/vhost/net.c')
-rw-r--r-- | drivers/vhost/net.c | 321 |
1 files changed, 206 insertions, 115 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index ec6fb3fa59bb..a3645bd163d8 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -64,20 +64,36 @@ enum { 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; @@ -88,6 +104,90 @@ struct vhost_net { 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; @@ -155,28 +255,6 @@ static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, } } -/* 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 @@ -185,10 +263,12 @@ static int tx_poll_start(struct vhost_net *net, struct socket *sock) 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)) { @@ -200,7 +280,7 @@ static int vhost_zerocopy_signal_used(struct vhost_net *net, break; } if (j) - vq->done_idx = i; + nvq->done_idx = i; return j; } @@ -230,7 +310,8 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) * 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 = { @@ -242,7 +323,7 @@ static void handle_tx(struct vhost_net *net) .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); @@ -253,21 +334,11 @@ static void handle_tx(struct vhost_net *net) 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 */ @@ -285,23 +356,15 @@ static void handle_tx(struct vhost_net *net) 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; @@ -314,45 +377,45 @@ static void handle_tx(struct vhost_net *net) 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); @@ -360,12 +423,10 @@ static void handle_tx(struct vhost_net *net) 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) @@ -470,7 +531,8 @@ err: * 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 = { @@ -498,8 +560,8 @@ static void handle_rx(struct vhost_net *net) 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; @@ -529,11 +591,11 @@ static void handle_rx(struct vhost_net *net) /* 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); @@ -547,7 +609,7 @@ static void handle_rx(struct vhost_net *net) 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); @@ -555,7 +617,7 @@ static void handle_rx(struct vhost_net *net) } /* 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"); @@ -612,23 +674,39 @@ static int vhost_net_open(struct inode *inode, struct file *f) { 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; @@ -638,32 +716,28 @@ static int vhost_net_open(struct inode *inode, struct file *f) 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, @@ -683,30 +757,30 @@ 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); } } @@ -720,6 +794,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) 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) @@ -727,6 +802,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) /* 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; } @@ -800,6 +876,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) { struct socket *sock, *oldsock; struct vhost_virtqueue *vq; + struct vhost_net_virtqueue *nvq; struct vhost_ubuf_ref *ubufs, *oldubufs = NULL; int r; @@ -812,7 +889,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) 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. */ @@ -845,8 +923,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) 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; @@ -889,14 +967,21 @@ static long vhost_net_reset_owner(struct vhost_net *n) struct socket *tx_sock = NULL; struct socket *rx_sock = NULL; long err; + struct vhost_memory *memory; mutex_lock(&n->dev.mutex); err = vhost_dev_check_owner(&n->dev); if (err) goto done; + memory = vhost_dev_reset_owner_prepare(); + if (!memory) { + err = -ENOMEM; + goto done; + } vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); - err = vhost_dev_reset_owner(&n->dev); + vhost_dev_reset_owner(&n->dev, memory); + vhost_net_vq_reset(n); done: mutex_unlock(&n->dev.mutex); if (tx_sock) @@ -932,10 +1017,10 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) 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); @@ -972,11 +1057,17 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, 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; } |