diff options
Diffstat (limited to 'drivers/vhost/net.c')
| -rw-r--r-- | drivers/vhost/net.c | 213 |
1 files changed, 168 insertions, 45 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 3c6ca66cb819..307c9d45ec48 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -67,7 +67,8 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" enum { VHOST_NET_FEATURES = VHOST_FEATURES | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | - (1ULL << VIRTIO_NET_F_MRG_RXBUF) + (1ULL << VIRTIO_NET_F_MRG_RXBUF) | + (1ULL << VIRTIO_F_IOMMU_PLATFORM) }; enum { @@ -293,6 +294,69 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) rcu_read_unlock_bh(); } +static inline unsigned long busy_clock(void) +{ + return local_clock() >> 10; +} + +static bool vhost_can_busy_poll(struct vhost_dev *dev, + unsigned long endtime) +{ + return likely(!need_resched()) && + likely(!time_after(busy_clock(), endtime)) && + likely(!signal_pending(current)) && + !vhost_has_work(dev); +} + +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; + 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; + + sock = vq->private_data; + if (!sock) + return 0; + + return vhost_poll_start(poll, sock->file); +} + +static int vhost_net_tx_get_vq_desc(struct vhost_net *net, + struct vhost_virtqueue *vq, + struct iovec iov[], unsigned int iov_size, + unsigned int *out_num, unsigned int *in_num) +{ + unsigned long uninitialized_var(endtime); + int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), + out_num, in_num, NULL, NULL); + + if (r == vq->num && vq->busyloop_timeout) { + preempt_disable(); + endtime = busy_clock() + vq->busyloop_timeout; + while (vhost_can_busy_poll(vq->dev, endtime) && + vhost_vq_avail_empty(vq->dev, vq)) + cpu_relax_lowlatency(); + preempt_enable(); + r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), + out_num, in_num, NULL, NULL); + } + + return r; +} + /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ static void handle_tx(struct vhost_net *net) @@ -322,6 +386,9 @@ static void handle_tx(struct vhost_net *net) if (!sock) goto out; + if (!vq_iotlb_prefetch(vq)) + goto out; + vhost_disable_notify(&net->dev, vq); hdr_size = nvq->vhost_hlen; @@ -339,10 +406,9 @@ static void handle_tx(struct vhost_net *net) % UIO_MAXIOV == nvq->done_idx)) break; - head = vhost_get_vq_desc(vq, vq->iov, - ARRAY_SIZE(vq->iov), - &out, &in, - NULL, NULL); + head = vhost_net_tx_get_vq_desc(net, vq, vq->iov, + ARRAY_SIZE(vq->iov), + &out, &in); /* On error, stop handling until the next kick. */ if (unlikely(head < 0)) break; @@ -438,6 +504,43 @@ static int peek_head_len(struct sock *sk) return len; } +static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) +{ + struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; + struct vhost_virtqueue *vq = &nvq->vq; + unsigned long uninitialized_var(endtime); + int len = peek_head_len(sk); + + if (!len && vq->busyloop_timeout) { + /* Both tx vq and rx socket were polled here */ + mutex_lock_nested(&vq->mutex, 1); + vhost_disable_notify(&net->dev, vq); + + preempt_disable(); + endtime = busy_clock() + vq->busyloop_timeout; + + while (vhost_can_busy_poll(&net->dev, endtime) && + skb_queue_empty(&sk->sk_receive_queue) && + vhost_vq_avail_empty(&net->dev, vq)) + cpu_relax_lowlatency(); + + preempt_enable(); + + if (!vhost_vq_avail_empty(&net->dev, vq)) + vhost_poll_queue(&vq->poll); + else if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_disable_notify(&net->dev, vq); + vhost_poll_queue(&vq->poll); + } + + mutex_unlock(&vq->mutex); + + len = peek_head_len(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 @@ -544,11 +647,16 @@ static void handle_rx(struct vhost_net *net) __virtio16 num_buffers; int recv_pkts = 0; - mutex_lock(&vq->mutex); + mutex_lock_nested(&vq->mutex, 0); sock = vq->private_data; if (!sock) goto out; + + if (!vq_iotlb_prefetch(vq)) + goto out; + vhost_disable_notify(&net->dev, vq); + vhost_net_disable_vq(net, vq); vhost_hlen = nvq->vhost_hlen; sock_hlen = nvq->sock_hlen; @@ -558,7 +666,7 @@ static void handle_rx(struct vhost_net *net) mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); do { - sock_len = peek_head_len(sock->sk); + sock_len = vhost_net_rx_peek_head_len(net, sock->sk); if (!sock_len) break; sock_len += sock_hlen; @@ -568,7 +676,7 @@ static void handle_rx(struct vhost_net *net) likely(mergeable) ? UIO_MAXIOV : 1); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) - break; + goto out; /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); @@ -587,7 +695,7 @@ static void handle_rx(struct vhost_net *net) } /* Nothing new? Wait for eventfd to tell us * they refilled. */ - break; + goto out; } /* We don't need to be notified again. */ iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len); @@ -615,7 +723,7 @@ static void handle_rx(struct vhost_net *net) &fixup) != sizeof(hdr)) { vq_err(vq, "Unable to write vnet_hdr " "at addr %p\n", vq->iov->iov_base); - break; + goto out; } } else { /* Header came from socket; we'll need to patch @@ -631,7 +739,7 @@ static void handle_rx(struct vhost_net *net) &fixup) != sizeof num_buffers) { vq_err(vq, "Failed num_buffers write"); vhost_discard_vq_desc(vq, headcount); - break; + goto out; } vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, headcount); @@ -640,6 +748,8 @@ static void handle_rx(struct vhost_net *net) total_len += vhost_len; } while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len))); + vhost_net_enable_vq(net, vq); + out: mutex_unlock(&vq->mutex); } @@ -719,32 +829,6 @@ static int vhost_net_open(struct inode *inode, struct file *f) return 0; } -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; - 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; - - sock = vq->private_data; - if (!sock) - return 0; - - return vhost_poll_start(poll, sock->file); -} - static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct vhost_virtqueue *vq) { @@ -913,7 +997,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) vhost_net_disable_vq(n, vq); vq->private_data = sock; - r = vhost_init_used(vq); + r = vhost_vq_init_access(vq); if (r) goto err_used; r = vhost_net_enable_vq(n, vq); @@ -965,21 +1049,21 @@ 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; + struct vhost_umem *umem; mutex_lock(&n->dev.mutex); err = vhost_dev_check_owner(&n->dev); if (err) goto done; - memory = vhost_dev_reset_owner_prepare(); - if (!memory) { + umem = vhost_dev_reset_owner_prepare(); + if (!umem) { err = -ENOMEM; goto done; } vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_stop(&n->dev); - vhost_dev_reset_owner(&n->dev, memory); + vhost_dev_reset_owner(&n->dev, umem); vhost_net_vq_reset(n); done: mutex_unlock(&n->dev.mutex); @@ -1010,10 +1094,14 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) } mutex_lock(&n->dev.mutex); if ((features & (1 << VHOST_F_LOG_ALL)) && - !vhost_log_access_ok(&n->dev)) { - mutex_unlock(&n->dev.mutex); - return -EFAULT; + !vhost_log_access_ok(&n->dev)) + goto out_unlock; + + if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) { + if (vhost_init_device_iotlb(&n->dev, true)) + goto out_unlock; } + for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { mutex_lock(&n->vqs[i].vq.mutex); n->vqs[i].vq.acked_features = features; @@ -1023,6 +1111,10 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) } mutex_unlock(&n->dev.mutex); return 0; + +out_unlock: + mutex_unlock(&n->dev.mutex); + return -EFAULT; } static long vhost_net_set_owner(struct vhost_net *n) @@ -1096,9 +1188,40 @@ static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, } #endif +static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + int noblock = file->f_flags & O_NONBLOCK; + + return vhost_chr_read_iter(dev, to, noblock); +} + +static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb, + struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + + return vhost_chr_write_iter(dev, from); +} + +static unsigned int vhost_net_chr_poll(struct file *file, poll_table *wait) +{ + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + + return vhost_chr_poll(file, dev, wait); +} + static const struct file_operations vhost_net_fops = { .owner = THIS_MODULE, .release = vhost_net_release, + .read_iter = vhost_net_chr_read_iter, + .write_iter = vhost_net_chr_write_iter, + .poll = vhost_net_chr_poll, .unlocked_ioctl = vhost_net_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = vhost_net_compat_ioctl, |