diff options
| -rw-r--r-- | drivers/vhost/net.c | 82 | ||||
| -rw-r--r-- | include/linux/uio.h | 3 | ||||
| -rw-r--r-- | lib/iovec.c | 26 |
3 files changed, 23 insertions, 88 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index d86cc9bb9ea4..e022cc40303d 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -84,10 +84,6 @@ struct vhost_net_ubuf_ref { 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: */ @@ -235,44 +231,6 @@ static bool vhost_sock_zcopy(struct socket *sock) 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; - to->iov_len = size; - from->iov_len -= size; - from->iov_base += size; - len -= size; - ++from; - ++to; - ++seg; - } - 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; - } -} - /* 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 @@ -570,9 +528,9 @@ static void handle_rx(struct vhost_net *net) .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, }; - struct virtio_net_hdr_mrg_rxbuf hdr = { - .hdr.flags = 0, - .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE + struct virtio_net_hdr hdr = { + .flags = 0, + .gso_type = VIRTIO_NET_HDR_GSO_NONE }; size_t total_len = 0; int err, mergeable; @@ -580,6 +538,7 @@ static void handle_rx(struct vhost_net *net) size_t vhost_hlen, sock_hlen; size_t vhost_len, sock_len; struct socket *sock; + struct iov_iter fixup; mutex_lock(&vq->mutex); sock = vq->private_data; @@ -624,14 +583,19 @@ static void handle_rx(struct vhost_net *net) break; } /* We don't need to be notified again. */ - if (unlikely((vhost_hlen))) - /* Skip header. TODO: support TSO. */ - 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, nvq->hdr, sock_hlen, in); - iov_iter_init(&msg.msg_iter, READ, vq->iov, in, sock_len); + iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len); + fixup = msg.msg_iter; + if (unlikely((vhost_hlen))) { + /* We will supply the header ourselves + * TODO: support TSO. + */ + iov_iter_advance(&msg.msg_iter, vhost_hlen); + } else { + /* It'll come from socket; we'll need to patch + * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF + */ + iov_iter_advance(&fixup, sizeof(hdr)); + } err = sock->ops->recvmsg(NULL, sock, &msg, sock_len, MSG_DONTWAIT | MSG_TRUNC); /* Userspace might have consumed the packet meanwhile: @@ -643,18 +607,18 @@ static void handle_rx(struct vhost_net *net) vhost_discard_vq_desc(vq, headcount); continue; } + /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ if (unlikely(vhost_hlen) && - memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0, - vhost_hlen)) { + copy_to_iter(&hdr, sizeof(hdr), &fixup) != sizeof(hdr)) { vq_err(vq, "Unable to write vnet_hdr at addr %p\n", vq->iov->iov_base); break; } - /* TODO: Should check and handle checksum. */ + /* Supply (or replace) ->num_buffers if VIRTIO_NET_F_MRG_RXBUF + * TODO: Should check and handle checksum. + */ if (likely(mergeable) && - memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount, - offsetof(typeof(hdr), num_buffers), - sizeof hdr.num_buffers)) { + copy_to_iter(&headcount, 2, &fixup) != 2) { vq_err(vq, "Failed num_buffers write"); vhost_discard_vq_desc(vq, headcount); break; diff --git a/include/linux/uio.h b/include/linux/uio.h index af3439f4ebf2..02bd8a92038a 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -137,7 +137,4 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct io int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, int offset, int len); -int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata, - int offset, int len); - #endif diff --git a/lib/iovec.c b/lib/iovec.c index 4a90875c64ae..d8f17a9b1ccf 100644 --- a/lib/iovec.c +++ b/lib/iovec.c @@ -3,32 +3,6 @@ #include <linux/uio.h> /* - * Copy kernel to iovec. Returns -EFAULT on error. - */ - -int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, - int offset, int len) -{ - int copy; - for (; len > 0; ++iov) { - /* Skip over the finished iovecs */ - if (unlikely(offset >= iov->iov_len)) { - offset -= iov->iov_len; - continue; - } - copy = min_t(unsigned int, iov->iov_len - offset, len); - if (copy_to_user(iov->iov_base + offset, kdata, copy)) - return -EFAULT; - offset = 0; - kdata += copy; - len -= copy; - } - - return 0; -} -EXPORT_SYMBOL(memcpy_toiovecend); - -/* * Copy iovec to kernel. Returns -EFAULT on error. */ |