diff options
Diffstat (limited to 'drivers/vhost/net.c')
| -rw-r--r-- | drivers/vhost/net.c | 784 |
1 files changed, 522 insertions, 262 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 4b4da5b86ff..8dae2f724a3 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -10,57 +10,237 @@ #include <linux/eventfd.h> #include <linux/vhost.h> #include <linux/virtio_net.h> -#include <linux/mmu_context.h> #include <linux/miscdevice.h> #include <linux/module.h> +#include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/workqueue.h> -#include <linux/rcupdate.h> #include <linux/file.h> #include <linux/slab.h> +#include <linux/vmalloc.h> #include <linux/net.h> #include <linux/if_packet.h> #include <linux/if_arp.h> #include <linux/if_tun.h> #include <linux/if_macvlan.h> +#include <linux/if_vlan.h> #include <net/sock.h> #include "vhost.h" +static int experimental_zcopytx = 1; +module_param(experimental_zcopytx, int, 0444); +MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" + " 1 -Enable; 0 - Disable"); + /* Max number of bytes transferred before requeueing the job. * Using this limit prevents one virtqueue from starving others. */ #define VHOST_NET_WEIGHT 0x80000 +/* MAX number of TX used buffers for outstanding zerocopy */ +#define VHOST_MAX_PEND 128 +#define VHOST_GOODCOPY_LEN 256 + +/* + * For transmit, used buffer len is unused; we override it to track buffer + * status internally; used for zerocopy tx only. + */ +/* Lower device DMA failed */ +#define VHOST_DMA_FAILED_LEN 3 +/* Lower device DMA done */ +#define VHOST_DMA_DONE_LEN 2 +/* Lower device DMA in progress */ +#define VHOST_DMA_IN_PROGRESS 1 +/* Buffer unused */ +#define VHOST_DMA_CLEAR_LEN 0 + +#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN) + +enum { + VHOST_NET_FEATURES = VHOST_FEATURES | + (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | + (1ULL << VIRTIO_NET_F_MRG_RXBUF), +}; + enum { VHOST_NET_VQ_RX = 0, VHOST_NET_VQ_TX = 1, 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_net_ubuf_ref { + /* refcount follows semantics similar to kref: + * 0: object is released + * 1: no outstanding ubufs + * >1: outstanding ubufs + */ + atomic_t refcount; + 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_net_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. + /* Number of TX recently submitted. * Protected by tx vq lock. */ - enum vhost_net_poll_state tx_poll_state; + unsigned tx_packets; + /* Number of times zerocopy TX recently failed. + * Protected by tx vq lock. */ + unsigned tx_zcopy_err; + /* Flush in progress. Protected by tx vq lock. */ + bool tx_flush; }; +static unsigned vhost_net_zcopy_mask __read_mostly; + +static void vhost_net_enable_zcopy(int vq) +{ + vhost_net_zcopy_mask |= 0x1 << vq; +} + +static struct vhost_net_ubuf_ref * +vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy) +{ + struct vhost_net_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); + atomic_set(&ubufs->refcount, 1); + init_waitqueue_head(&ubufs->wait); + ubufs->vq = vq; + return ubufs; +} + +static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) +{ + int r = atomic_sub_return(1, &ubufs->refcount); + if (unlikely(!r)) + wake_up(&ubufs->wait); + return r; +} + +static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs) +{ + vhost_net_ubuf_put(ubufs); + wait_event(ubufs->wait, !atomic_read(&ubufs->refcount)); +} + +static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs) +{ + vhost_net_ubuf_put_and_wait(ubufs); + kfree(ubufs); +} + +static void vhost_net_clear_ubuf_info(struct vhost_net *n) +{ + int i; + + for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { + kfree(n->vqs[i].ubuf_info); + n->vqs[i].ubuf_info = NULL; + } +} + +static int vhost_net_set_ubuf_info(struct vhost_net *n) +{ + bool zcopy; + int i; + + for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { + zcopy = vhost_net_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: + vhost_net_clear_ubuf_info(n); + return -ENOMEM; +} + +static void vhost_net_vq_reset(struct vhost_net *n) +{ + int i; + + vhost_net_clear_ubuf_info(n); + + 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; + 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; + if (net->tx_packets < 1024) + return; + net->tx_packets = 0; + net->tx_zcopy_err = 0; +} + +static void vhost_net_tx_err(struct vhost_net *net) +{ + ++net->tx_zcopy_err; +} + +static bool vhost_net_tx_select_zcopy(struct vhost_net *net) +{ + /* TX flush waits for outstanding DMAs to be done. + * Don't start new DMAs. + */ + return !net->tx_flush && + net->tx_packets / 64 >= net->tx_zcopy_err; +} + +static bool vhost_sock_zcopy(struct socket *sock) +{ + return unlikely(experimental_zcopytx) && + sock_flag(sock->sk, SOCK_ZEROCOPY); +} + /* Pop first len bytes from iovec. Return number of segments used. */ static int move_iovec_hdr(struct iovec *from, struct iovec *to, size_t len, int iov_count) { int seg = 0; size_t size; + while (len && seg < iov_count) { size = min(from->iov_len, len); to->iov_base = from->iov_base; @@ -80,6 +260,7 @@ static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, { int seg = 0; size_t size; + while (len && seg < iovcount) { size = min(from->iov_len, len); to->iov_base = from->iov_base; @@ -91,29 +272,69 @@ 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) +/* 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 + * guest used idx. + */ +static void vhost_zerocopy_signal_used(struct vhost_net *net, + struct vhost_virtqueue *vq) { - 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; + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); + int i, add; + int j = 0; + + 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)) { + vq->heads[i].len = VHOST_DMA_CLEAR_LEN; + ++j; + } else + break; + } + while (j) { + add = min(UIO_MAXIOV - nvq->done_idx, j); + vhost_add_used_and_signal_n(vq->dev, vq, + &vq->heads[nvq->done_idx], add); + nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV; + j -= add; + } } -/* Caller must have TX VQ lock */ -static void tx_poll_start(struct vhost_net *net, struct socket *sock) +static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) { - if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED)) - return; - vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file); - net->tx_poll_state = VHOST_NET_POLL_STARTED; + struct vhost_net_ubuf_ref *ubufs = ubuf->ctx; + struct vhost_virtqueue *vq = ubufs->vq; + int cnt; + + rcu_read_lock_bh(); + + /* set len to mark this desc buffers done DMA */ + vq->heads[ubuf->desc].len = success ? + VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN; + cnt = vhost_net_ubuf_put(ubufs); + + /* + * Trigger polling thread if guest stopped submitting new buffers: + * in this case, the refcount after decrement will eventually reach 1. + * We also trigger polling periodically after each 16 packets + * (the value 16 here is more or less arbitrary, it's tuned to trigger + * less than 10% of times). + */ + if (cnt <= 1 || !(cnt % 16)) + vhost_poll_queue(&vq->poll); + + rcu_read_unlock_bh(); } /* 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) { - 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 = { @@ -125,33 +346,35 @@ 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_net_ubuf_ref *uninitialized_var(ubufs); + bool zcopy, zcopy_used; - sock = rcu_dereference_check(vq->private_data, - lockdep_is_held(&vq->mutex)); + mutex_lock(&vq->mutex); + sock = vq->private_data; 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; - } + goto out; - use_mm(net->dev.mm); - mutex_lock(&vq->mutex); - vhost_disable_notify(vq); + vhost_disable_notify(&net->dev, vq); - if (wmem < sock->sk->sk_sndbuf / 2) - tx_poll_stop(net); - hdr_size = vq->vhost_hlen; + hdr_size = nvq->vhost_hlen; + zcopy = nvq->ubufs; for (;;) { - head = vhost_get_vq_desc(&net->dev, vq, vq->iov, + /* Release DMAs done buffers first */ + if (zcopy) + vhost_zerocopy_signal_used(net, vq); + + /* If more outstanding DMAs, queue the work. + * Handle upend_idx wrap around + */ + if (unlikely((nvq->upend_idx + vq->num - VHOST_MAX_PEND) + % UIO_MAXIOV == nvq->done_idx)) + break; + + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), &out, &in, NULL, NULL); @@ -160,14 +383,8 @@ static void handle_tx(struct vhost_net *net) break; /* Nothing new? Wait for eventfd to tell us they refilled. */ if (head == vq->num) { - 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 (unlikely(vhost_enable_notify(vq))) { - vhost_disable_notify(vq); + if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_disable_notify(&net->dev, vq); continue; } break; @@ -178,48 +395,85 @@ 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 + && (nvq->upend_idx + 1) % UIO_MAXIOV != + nvq->done_idx + && vhost_net_tx_select_zcopy(net); + + /* use msg_control to pass vhost zerocopy ubuf info to skb */ + if (zcopy_used) { + struct ubuf_info *ubuf; + ubuf = nvq->ubuf_info + nvq->upend_idx; + + vq->heads[nvq->upend_idx].id = head; + vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; + ubuf->callback = vhost_zerocopy_callback; + ubuf->ctx = nvq->ubufs; + ubuf->desc = nvq->upend_idx; + msg.msg_control = ubuf; + msg.msg_controllen = sizeof(ubuf); + ubufs = nvq->ubufs; + atomic_inc(&ubufs->refcount); + nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; + } else { + msg.msg_control = NULL; + ubufs = NULL; + } /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(NULL, sock, &msg, len); if (unlikely(err < 0)) { + if (zcopy_used) { + vhost_net_ubuf_put(ubufs); + nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) + % UIO_MAXIOV; + } vhost_discard_vq_desc(vq, 1); - tx_poll_start(net, sock); break; } if (err != len) pr_debug("Truncated TX packet: " " len %d != %zd\n", err, len); - vhost_add_used_and_signal(&net->dev, vq, head, 0); + if (!zcopy_used) + vhost_add_used_and_signal(&net->dev, vq, head, 0); + else + vhost_zerocopy_signal_used(net, vq); total_len += len; + vhost_net_tx_packet(net); if (unlikely(total_len >= VHOST_NET_WEIGHT)) { vhost_poll_queue(&vq->poll); break; } } - +out: mutex_unlock(&vq->mutex); - unuse_mm(net->dev.mm); } static int peek_head_len(struct sock *sk) { struct sk_buff *head; int len = 0; + unsigned long flags; - lock_sock(sk); + spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); head = skb_peek(&sk->sk_receive_queue); - if (head) + if (likely(head)) { len = head->len; - release_sock(sk); + if (vlan_tx_tag_present(head)) + len += VLAN_HLEN; + } + + spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); return len; } @@ -230,6 +484,7 @@ static int peek_head_len(struct sock *sk) * @iovcount - returned count of io vectors we fill * @log - vhost log * @log_num - log offset + * @quota - headcount quota, 1 for big buffer * returns number of buffer heads allocated, negative on error */ static int get_rx_bufs(struct vhost_virtqueue *vq, @@ -237,7 +492,8 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, int datalen, unsigned *iovcount, struct vhost_log *log, - unsigned *log_num) + unsigned *log_num, + unsigned int quota) { unsigned int out, in; int seg = 0; @@ -245,14 +501,18 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, unsigned d; int r, nlogs = 0; - while (datalen > 0) { + while (datalen > 0 && headcount < quota) { if (unlikely(seg >= UIO_MAXIOV)) { r = -ENOBUFS; goto err; } - d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, + r = vhost_get_vq_desc(vq, vq->iov + seg, ARRAY_SIZE(vq->iov) - seg, &out, &in, log, log_num); + if (unlikely(r < 0)) + goto err; + + d = r; if (d == vq->num) { r = 0; goto err; @@ -277,6 +537,12 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, *iovcount = seg; if (unlikely(log)) *log_num = nlogs; + + /* Detect overrun */ + if (unlikely(datalen > 0)) { + r = UIO_MAXIOV + 1; + goto err; + } return headcount; err: vhost_discard_vq_desc(vq, headcount); @@ -285,120 +551,10 @@ err: /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ -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; - int head; - 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 hdr = { - .flags = 0, - .gso_type = VIRTIO_NET_HDR_GSO_NONE - }; - - size_t len, total_len = 0; - int err; - size_t hdr_size; - 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); - hdr_size = vq->vhost_hlen; - - vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? - vq->log : NULL; - - for (;;) { - head = vhost_get_vq_desc(&net->dev, vq, vq->iov, - ARRAY_SIZE(vq->iov), - &out, &in, - vq_log, &log); - /* On error, stop handling until the next kick. */ - if (unlikely(head < 0)) - break; - /* OK, now we need to know about added descriptors. */ - if (head == vq->num) { - 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 (out) { - vq_err(vq, "Unexpected descriptor format for RX: " - "out %d, int %d\n", - out, in); - break; - } - /* Skip header. TODO: support TSO/mergeable rx buffers. */ - s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in); - msg.msg_iovlen = in; - len = iov_length(vq->iov, in); - /* Sanity check */ - if (!len) { - vq_err(vq, "Unexpected header len for RX: " - "%zd expected %zd\n", - iov_length(vq->hdr, s), hdr_size); - break; - } - err = sock->ops->recvmsg(NULL, sock, &msg, - len, MSG_DONTWAIT | MSG_TRUNC); - /* TODO: Check specific error and bomb out unless EAGAIN? */ - if (err < 0) { - 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, 1); - continue; - } - len = err; - err = memcpy_toiovec(vq->hdr, (unsigned char *)&hdr, hdr_size); - if (err) { - vq_err(vq, "Unable to write vnet_hdr at addr %p: %d\n", - vq->iov->iov_base, err); - break; - } - len += hdr_size; - vhost_add_used_and_signal(&net->dev, vq, head, len); - if (unlikely(vq_log)) - vhost_log_write(vq, vq_log, log, len); - total_len += len; - if (unlikely(total_len >= VHOST_NET_WEIGHT)) { - vhost_poll_queue(&vq->poll); - break; - } - } - - mutex_unlock(&vq->mutex); - 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) +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 = { @@ -409,43 +565,53 @@ static void handle_rx_mergeable(struct vhost_net *net) .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; + int err, mergeable; + s16 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; + struct socket *sock; - use_mm(net->dev.mm); mutex_lock(&vq->mutex); - vhost_disable_notify(vq); - vhost_hlen = vq->vhost_hlen; - sock_hlen = vq->sock_hlen; + sock = vq->private_data; + if (!sock) + goto out; + vhost_disable_notify(&net->dev, vq); - vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? + vhost_hlen = nvq->vhost_hlen; + sock_hlen = nvq->sock_hlen; + + vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ? vq->log : NULL; + mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); 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); + &in, vq_log, &log, + likely(mergeable) ? UIO_MAXIOV : 1); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) break; + /* On overrun, truncate and discard */ + if (unlikely(headcount > UIO_MAXIOV)) { + msg.msg_iovlen = 1; + err = sock->ops->recvmsg(NULL, sock, &msg, + 1, MSG_DONTWAIT | MSG_TRUNC); + pr_debug("Discarded rx packet: len %zd\n", sock_len); + continue; + } /* OK, now we need to know about added descriptors. */ if (!headcount) { - if (unlikely(vhost_enable_notify(vq))) { + if (unlikely(vhost_enable_notify(&net->dev, vq))) { /* They have slipped one in as we were * doing that: check again. */ - vhost_disable_notify(vq); + vhost_disable_notify(&net->dev, vq); continue; } /* Nothing new? Wait for eventfd to tell us @@ -455,11 +621,11 @@ static void handle_rx_mergeable(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 sendmsg can modify msg_iov. */ - copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in); + * needed because recvmsg can modify msg_iov. */ + 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); @@ -473,15 +639,15 @@ static void handle_rx_mergeable(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); 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, + if (likely(mergeable) && + memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount, offsetof(typeof(hdr), num_buffers), sizeof hdr.num_buffers)) { vq_err(vq, "Failed num_buffers write"); @@ -498,17 +664,8 @@ static void handle_rx_mergeable(struct vhost_net *net) break; } } - +out: 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) @@ -545,25 +702,40 @@ static void handle_rx_net(struct vhost_work *work) static int vhost_net_open(struct inode *inode, struct file *f) { - struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); + struct vhost_net *n; struct vhost_dev *dev; - int r; + struct vhost_virtqueue **vqs; + int i; - if (!n) + n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); + if (!n) { + n = vmalloc(sizeof *n); + if (!n) + return -ENOMEM; + } + vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL); + if (!vqs) { + kvfree(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); - if (r < 0) { - kfree(n); - return r; + 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; } + vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); 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; @@ -573,29 +745,27 @@ 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 void vhost_net_enable_vq(struct vhost_net *n, +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 = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + sock = vq->private_data; if (!sock) - return; - if (vq == n->vqs + VHOST_NET_VQ_TX) { - n->tx_poll_state = VHOST_NET_POLL_STOPPED; - tx_poll_start(n, sock); - } else - vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file); + return 0; + + return vhost_poll_start(poll, sock->file); } static struct socket *vhost_net_stop_vq(struct vhost_net *n, @@ -604,10 +774,9 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct socket *sock; mutex_lock(&vq->mutex); - sock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + sock = vq->private_data; vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, NULL); + vq->private_data = NULL; mutex_unlock(&vq->mutex); return sock; } @@ -615,20 +784,31 @@ 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->vqs[VHOST_NET_VQ_TX].ubufs) { + mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); + n->tx_flush = true; + mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); + /* Wait for all lower device DMAs done. */ + vhost_net_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; + atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1); + mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); + } } static int vhost_net_release(struct inode *inode, struct file *f) @@ -639,15 +819,20 @@ static int vhost_net_release(struct inode *inode, struct file *f) vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); - vhost_dev_cleanup(&n->dev); + vhost_dev_stop(&n->dev); + vhost_dev_cleanup(&n->dev, false); + vhost_net_vq_reset(n); if (tx_sock) - fput(tx_sock->file); + sockfd_put(tx_sock); if (rx_sock) - fput(rx_sock->file); + sockfd_put(rx_sock); + /* Make sure no callbacks are outstanding */ + synchronize_rcu_bh(); /* We do an extra flush before freeing memory, * since jobs can re-queue themselves. */ vhost_net_flush(n); - kfree(n); + kfree(n->dev.vqs); + kvfree(n); return 0; } @@ -659,6 +844,7 @@ static struct socket *get_raw_socket(int fd) } uaddr; int uaddr_len = sizeof uaddr, r; struct socket *sock = sockfd_lookup(fd, &r); + if (!sock) return ERR_PTR(-ENOTSOCK); @@ -679,7 +865,7 @@ static struct socket *get_raw_socket(int fd) } return sock; err: - fput(sock->file); + sockfd_put(sock); return ERR_PTR(r); } @@ -687,6 +873,7 @@ static struct socket *get_tap_socket(int fd) { struct file *file = fget(fd); struct socket *sock; + if (!file) return ERR_PTR(-EBADF); sock = tun_get_socket(file); @@ -701,6 +888,7 @@ static struct socket *get_tap_socket(int fd) static struct socket *get_socket(int fd) { struct socket *sock; + /* special case to disable backend */ if (fd == -1) return NULL; @@ -717,6 +905,8 @@ 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_net_ubuf_ref *ubufs, *oldubufs = NULL; int r; mutex_lock(&n->dev.mutex); @@ -728,7 +918,8 @@ 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. */ @@ -743,24 +934,56 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } /* start polling new socket */ - oldsock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + oldsock = vq->private_data; if (sock != oldsock) { - vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, sock); - vhost_net_enable_vq(n, vq); + ubufs = vhost_net_ubuf_alloc(vq, + sock && vhost_sock_zcopy(sock)); + if (IS_ERR(ubufs)) { + r = PTR_ERR(ubufs); + goto err_ubufs; + } + + vhost_net_disable_vq(n, vq); + vq->private_data = sock; + r = vhost_init_used(vq); + if (r) + goto err_used; + r = vhost_net_enable_vq(n, vq); + if (r) + goto err_used; + + oldubufs = nvq->ubufs; + nvq->ubufs = ubufs; + + n->tx_packets = 0; + n->tx_zcopy_err = 0; + n->tx_flush = false; } mutex_unlock(&vq->mutex); + if (oldubufs) { + vhost_net_ubuf_put_wait_and_free(oldubufs); + mutex_lock(&vq->mutex); + vhost_zerocopy_signal_used(n, vq); + mutex_unlock(&vq->mutex); + } + if (oldsock) { vhost_net_flush_vq(n, index); - fput(oldsock->file); + sockfd_put(oldsock); } mutex_unlock(&n->dev.mutex); return 0; +err_used: + vq->private_data = oldsock; + vhost_net_enable_vq(n, vq); + if (ubufs) + vhost_net_ubuf_put_wait_and_free(ubufs); +err_ubufs: + sockfd_put(sock); err_vq: mutex_unlock(&vq->mutex); err: @@ -773,19 +996,27 @@ 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) - fput(tx_sock->file); + sockfd_put(tx_sock); if (rx_sock) - fput(rx_sock->file); + sockfd_put(rx_sock); return err; } @@ -812,19 +1043,38 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) mutex_unlock(&n->dev.mutex); return -EFAULT; } - 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].vq.acked_features = features; 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 0; } +static long vhost_net_set_owner(struct vhost_net *n) +{ + int r; + + mutex_lock(&n->dev.mutex); + if (vhost_dev_has_owner(&n->dev)) { + r = -EBUSY; + goto out; + } + r = vhost_net_set_ubuf_info(n); + if (r) + goto out; + r = vhost_dev_set_owner(&n->dev); + if (r) + vhost_net_clear_ubuf_info(n); + vhost_net_flush(n); +out: + mutex_unlock(&n->dev.mutex); + return r; +} + static long vhost_net_ioctl(struct file *f, unsigned int ioctl, unsigned long arg) { @@ -834,28 +1084,34 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, struct vhost_vring_file backend; u64 features; int r; + switch (ioctl) { case VHOST_NET_SET_BACKEND: if (copy_from_user(&backend, argp, sizeof backend)) return -EFAULT; return vhost_net_set_backend(n, backend.index, backend.fd); case VHOST_GET_FEATURES: - features = VHOST_FEATURES; + features = VHOST_NET_FEATURES; if (copy_to_user(featurep, &features, sizeof features)) return -EFAULT; return 0; case VHOST_SET_FEATURES: if (copy_from_user(&features, featurep, sizeof features)) return -EFAULT; - if (features & ~VHOST_FEATURES) + if (features & ~VHOST_NET_FEATURES) return -EOPNOTSUPP; return vhost_net_set_features(n, features); case VHOST_RESET_OWNER: return vhost_net_reset_owner(n); + case VHOST_SET_OWNER: + return vhost_net_set_owner(n); default: mutex_lock(&n->dev.mutex); - r = vhost_dev_ioctl(&n->dev, ioctl, arg); - vhost_net_flush(n); + r = vhost_dev_ioctl(&n->dev, ioctl, argp); + if (r == -ENOIOCTLCMD) + r = vhost_vring_ioctl(&n->dev, ioctl, argp); + else + vhost_net_flush(n); mutex_unlock(&n->dev.mutex); return r; } @@ -881,13 +1137,15 @@ static const struct file_operations vhost_net_fops = { }; static struct miscdevice vhost_net_misc = { - MISC_DYNAMIC_MINOR, - "vhost-net", - &vhost_net_fops, + .minor = VHOST_NET_MINOR, + .name = "vhost-net", + .fops = &vhost_net_fops, }; static int vhost_net_init(void) { + if (experimental_zcopytx) + vhost_net_enable_zcopy(VHOST_NET_VQ_TX); return misc_register(&vhost_net_misc); } module_init(vhost_net_init); @@ -902,3 +1160,5 @@ MODULE_VERSION("0.0.1"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Michael S. Tsirkin"); MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); +MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR); +MODULE_ALIAS("devname:vhost-net"); |