Re: [PATCH v1 06/13] xen/pvcalls: implement listen command
From: Juergen Gross
Date: Mon Jul 24 2017 - 15:44:24 EST
On 22/07/17 02:11, Stefano Stabellini wrote:
> Send PVCALLS_LISTEN to the backend.
>
> Signed-off-by: Stefano Stabellini <stefano@xxxxxxxxxxx>
> CC: boris.ostrovsky@xxxxxxxxxx
> CC: jgross@xxxxxxxx
> ---
> drivers/xen/pvcalls-front.c | 49 +++++++++++++++++++++++++++++++++++++++++++++
> drivers/xen/pvcalls-front.h | 1 +
> 2 files changed, 50 insertions(+)
>
> diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
> index 71619bc..80fd5fb 100644
> --- a/drivers/xen/pvcalls-front.c
> +++ b/drivers/xen/pvcalls-front.c
> @@ -361,6 +361,55 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> return 0;
> }
>
> +int pvcalls_front_listen(struct socket *sock, int backlog)
> +{
> + struct pvcalls_bedata *bedata;
> + struct sock_mapping *map;
> + struct xen_pvcalls_request *req;
> + int notify, req_id, ret;
> +
> + if (!pvcalls_front_dev)
> + return -ENOTCONN;
> + bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> +
> + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head);
> + if (!map)
> + return -ENOTSOCK;
> +
> + if (map->passive.status != PVCALLS_STATUS_BIND)
> + return -EOPNOTSUPP;
> +
> + spin_lock(&bedata->pvcallss_lock);
> + req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
> + BUG_ON(req_id >= PVCALLS_NR_REQ_PER_RING);
BUG_ON() again!
Juergen
> + if (RING_FULL(&bedata->ring) ||
> + bedata->rsp[req_id].req_id != PVCALLS_INVALID_ID) {
> + spin_unlock(&bedata->pvcallss_lock);
> + return -EAGAIN;
> + }
> + req = RING_GET_REQUEST(&bedata->ring, req_id);
> + req->req_id = req_id;
> + req->cmd = PVCALLS_LISTEN;
> + req->u.listen.id = (uint64_t) sock;
> + req->u.listen.backlog = backlog;
> +
> + bedata->ring.req_prod_pvt++;
> + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
> + spin_unlock(&bedata->pvcallss_lock);
> + if (notify)
> + notify_remote_via_irq(bedata->irq);
> +
> + wait_event(bedata->inflight_req,
> + READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
> +
> + map->passive.status = PVCALLS_STATUS_LISTEN;
> + ret = bedata->rsp[req_id].ret;
> + /* read ret, then set this rsp slot to be reused */
> + smp_mb();
> + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID);
> + return ret;
> +}
> +
> static const struct xenbus_device_id pvcalls_front_ids[] = {
> { "pvcalls" },
> { "" }
> diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h
> index 8b0a274..aa8fe10 100644
> --- a/drivers/xen/pvcalls-front.h
> +++ b/drivers/xen/pvcalls-front.h
> @@ -9,5 +9,6 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
> int pvcalls_front_bind(struct socket *sock,
> struct sockaddr *addr,
> int addr_len);
> +int pvcalls_front_listen(struct socket *sock, int backlog);
>
> #endif
>