On Mon, Apr 23, 2018 at 01:34:53PM +0800, Jason Wang wrote:
> Move get_rx_bufs() to vhost.c and rename it to
> vhost_get_rx_bufs(). This helps to hide vring internal layout from
A small typo. Based on the code change in this patch, it
seems that this function is renamed to vhost_get_bufs().
Thanks
> specific device implementation. Packed ring implementation will
> benefit from this.
>
> Signed-off-by: Jason Wang <jasow...@redhat.com>
> ---
> 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 986058a..762aa81 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -664,83 +664,6 @@ 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)
> @@ -790,9 +713,9 @@ static void handle_rx(struct vhost_net *net)
> while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
> sock_len += sock_hlen;
> vhost_len = sock_len + vhost_hlen;
> - headcount = get_rx_bufs(vq, vq->heads + nheads, vhost_len,
> - &in, vq_log, &log,
> - likely(mergeable) ? UIO_MAXIOV : 1);
> + headcount = vhost_get_bufs(vq, vq->heads + nheads, 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 f3bd8e9..6b455f6 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -2097,6 +2097,84 @@ 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
>
