From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net-next V2 1/8] vhost: move get_rx_bufs to vhost.c Date: Mon, 16 Jul 2018 11:28:04 +0800 Message-ID: <1531711691-6769-2-git-send-email-jasowang__10619.0805476674$1531711607$gmane$org@redhat.com> References: <1531711691-6769-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1531711691-6769-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: mst@redhat.com, jasowang@redhat.com Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, maxime.coquelin@redhat.com, wexu@redhat.com List-Id: virtualization@lists.linuxfoundation.org Move get_rx_bufs() to vhost.c and rename it to vhost_get_bufs(). This helps to hide vring internal layout from specific device implementation. Packed ring implementation will benefit from this. Signed-off-by: Jason Wang --- drivers/vhost/net.c | 83 ++------------------------------------------------- drivers/vhost/vhost.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/vhost/vhost.h | 7 +++++ 3 files changed, 88 insertions(+), 80 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index b224036..03dd1de 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -702,83 +702,6 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *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 - * @datalen - data length we'll be reading - * @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, - struct vring_used_elem *heads, - int datalen, - unsigned *iovcount, - struct vhost_log *log, - unsigned *log_num, - unsigned int quota) -{ - unsigned int out, in; - int seg = 0; - int headcount = 0; - unsigned d; - int r, nlogs = 0; - /* len is always initialized before use since we are always called with - * datalen > 0. - */ - u32 uninitialized_var(len); - - while (datalen > 0 && headcount < quota) { - if (unlikely(seg >= UIO_MAXIOV)) { - r = -ENOBUFS; - goto err; - } - 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; - } - if (unlikely(out || in <= 0)) { - vq_err(vq, "unexpected descriptor format for RX: " - "out %d, in %d\n", out, in); - r = -EINVAL; - goto err; - } - if (unlikely(log)) { - nlogs += *log_num; - log += *log_num; - } - heads[headcount].id = cpu_to_vhost32(vq, d); - len = iov_length(vq->iov + seg, in); - heads[headcount].len = cpu_to_vhost32(vq, len); - datalen -= len; - ++headcount; - seg += in; - } - heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); - *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); - return r; -} - /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ static void handle_rx(struct vhost_net *net) @@ -831,9 +754,9 @@ static void handle_rx(struct vhost_net *net) &busyloop_intr))) { sock_len += sock_hlen; vhost_len = sock_len + vhost_hlen; - headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx, - vhost_len, &in, vq_log, &log, - likely(mergeable) ? UIO_MAXIOV : 1); + headcount = vhost_get_bufs(vq, vq->heads + nvq->done_idx, + vhost_len, &in, vq_log, &log, + likely(mergeable) ? UIO_MAXIOV : 1); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) goto out; diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index a502f1a..8814e5b 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2104,6 +2104,84 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, } EXPORT_SYMBOL_GPL(vhost_get_vq_desc); +/* This is a multi-buffer version of vhost_get_desc, that works if + * vq has read descriptors only. + * @vq - the relevant virtqueue + * @datalen - data length we'll be reading + * @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 + */ +int vhost_get_bufs(struct vhost_virtqueue *vq, + struct vring_used_elem *heads, + int datalen, + unsigned *iovcount, + struct vhost_log *log, + unsigned *log_num, + unsigned int quota) +{ + unsigned int out, in; + int seg = 0; + int headcount = 0; + unsigned d; + int r, nlogs = 0; + /* len is always initialized before use since we are always called with + * datalen > 0. + */ + u32 uninitialized_var(len); + + while (datalen > 0 && headcount < quota) { + if (unlikely(seg >= UIO_MAXIOV)) { + r = -ENOBUFS; + goto err; + } + 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; + } + if (unlikely(out || in <= 0)) { + vq_err(vq, "unexpected descriptor format for RX: " + "out %d, in %d\n", out, in); + r = -EINVAL; + goto err; + } + if (unlikely(log)) { + nlogs += *log_num; + log += *log_num; + } + heads[headcount].id = cpu_to_vhost32(vq, d); + len = iov_length(vq->iov + seg, in); + heads[headcount].len = cpu_to_vhost32(vq, len); + datalen -= len; + ++headcount; + seg += in; + } + heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); + *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); + return r; +} +EXPORT_SYMBOL_GPL(vhost_get_bufs); + /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) { diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 6c844b9..52edd242 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -185,6 +185,13 @@ int vhost_get_vq_desc(struct vhost_virtqueue *, struct iovec iov[], unsigned int iov_count, unsigned int *out_num, unsigned int *in_num, struct vhost_log *log, unsigned int *log_num); +int vhost_get_bufs(struct vhost_virtqueue *vq, + struct vring_used_elem *heads, + int datalen, + unsigned *iovcount, + struct vhost_log *log, + unsigned *log_num, + unsigned int quota); void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); int vhost_vq_init_access(struct vhost_virtqueue *); -- 2.7.4