lkml.org 
[lkml]   [2017]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 08/18] xen/pvcalls: implement connect command
From
Date


On 05/15/2017 04:36 PM, Stefano Stabellini wrote:
> Allocate a socket. Keep track of socket <-> ring mappings with a new data
> structure, called sock_mapping. Implement the connect command by calling
> inet_stream_connect, and mapping the new indexes page and data ring.
> Associate the socket to an ioworker randomly.
>
> When an active socket is closed (sk_state_change), set in_error to
> -ENOTCONN and notify the other end, as specified by the protocol.
>
> sk_data_ready will be implemented later.
>
> Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
> CC: boris.ostrovsky@oracle.com
> CC: jgross@suse.com
> ---
> drivers/xen/pvcalls-back.c | 145 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 145 insertions(+)
>
> diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
> index 2eae096..9ac1cf2 100644
> --- a/drivers/xen/pvcalls-back.c
> +++ b/drivers/xen/pvcalls-back.c
> @@ -63,6 +63,29 @@ struct pvcalls_back_priv {
> struct work_struct register_work;
> };
>
> +struct sock_mapping {
> + struct list_head list;
> + struct list_head queue;

Since you have two lists it would be helpful if names were a bit more
descriptive.

(and comments for at least some fields would be welcome too)

> + struct pvcalls_back_priv *priv;
> + struct socket *sock;
> + int data_worker;
> + uint64_t id;
> + grant_ref_t ref;
> + struct pvcalls_data_intf *ring;
> + void *bytes;
> + struct pvcalls_data data;
> + uint32_t ring_order;
> + int irq;
> + atomic_t read;
> + atomic_t write;
> + atomic_t release;
> + void (*saved_data_ready)(struct sock *sk);
> +};
> +
> +static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map);
> +static int pvcalls_back_release_active(struct xenbus_device *dev,
> + struct pvcalls_back_priv *priv,
> + struct sock_mapping *map);
> static void pvcalls_back_ioworker(struct work_struct *work)
> {
> }
> @@ -97,9 +120,126 @@ static int pvcalls_back_socket(struct xenbus_device *dev,
> return 1;
> }
>
> +static void pvcalls_sk_state_change(struct sock *sock)
> +{
> + struct sock_mapping *map = sock->sk_user_data;
> + struct pvcalls_data_intf *intf;
> +
> + if (map == NULL)
> + return;
> +
> + intf = map->ring;
> + intf->in_error = -ENOTCONN;
> + notify_remote_via_irq(map->irq);
> +}
> +
> +static void pvcalls_sk_data_ready(struct sock *sock)
> +{
> +}
> +
> static int pvcalls_back_connect(struct xenbus_device *dev,
> struct xen_pvcalls_request *req)
> {
> + struct pvcalls_back_priv *priv;
> + int ret;
> + struct socket *sock;
> + struct sock_mapping *map = NULL;
> + void *page;
> + struct xen_pvcalls_response *rsp;
> +
> + if (dev == NULL)
> + return 0;
> + priv = dev_get_drvdata(&dev->dev);
> +
> + map = kzalloc(sizeof(*map), GFP_KERNEL);
> + if (map == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
> + if (ret < 0) {
> + kfree(map);
> + goto out;
> + }
> + INIT_LIST_HEAD(&map->queue);
> + map->data_worker = get_random_int() % pvcalls_back_global.nr_ioworkers;
> +
> + map->priv = priv;
> + map->sock = sock;
> + map->id = req->u.connect.id;
> + map->ref = req->u.connect.ref;
> +
> + ret = xenbus_map_ring_valloc(dev, &req->u.connect.ref, 1, &page);
> + if (ret < 0) {
> + sock_release(map->sock);
> + kfree(map);
> + goto out;
> + }
> + map->ring = page;
> + map->ring_order = map->ring->ring_order;
> + /* first read the order, then map the data ring */
> + virt_rmb();


Not sure I understand what the barrier is for here. I don't think
compiler will reorder ring_order access with the call.


> + if (map->ring_order > MAX_RING_ORDER) {
> + ret = -EFAULT;
> + goto out;
> + }

If the barrier is indeed needed this check belongs before it.

-boris


> + ret = xenbus_map_ring_valloc(dev, map->ring->ref,
> + (1 << map->ring_order), &page);
> + if (ret < 0) {
> + sock_release(map->sock);
> + xenbus_unmap_ring_vfree(dev, map->ring);
> + kfree(map);
> + goto out;
> + }
> + map->bytes = page;
> +
> + ret = bind_interdomain_evtchn_to_irqhandler(priv->dev->otherend_id,
> + req->u.connect.evtchn,
> + pvcalls_back_conn_event,
> + 0,
> + "pvcalls-backend",
> + map);
> + if (ret < 0) {
> + sock_release(map->sock);
> + kfree(map);
> + goto out;
> + }
> + map->irq = ret;
> +
> + map->data.in = map->bytes;
> + map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order);
> +
> + down_write(&priv->pvcallss_lock);
> + list_add_tail(&map->list, &priv->socket_mappings);
> + up_write(&priv->pvcallss_lock);
> +
> + ret = inet_stream_connect(sock, (struct sockaddr *)&req->u.connect.addr,
> + req->u.connect.len, req->u.connect.flags);
> + if (ret < 0) {
> + pvcalls_back_release_active(dev, priv, map);
> + } else {
> + lock_sock(sock->sk);
> + map->saved_data_ready = sock->sk->sk_data_ready;
> + sock->sk->sk_user_data = map;
> + sock->sk->sk_data_ready = pvcalls_sk_data_ready;
> + sock->sk->sk_state_change = pvcalls_sk_state_change;
> + release_sock(sock->sk);
> + }
> +
> +out:
> + rsp = RING_GET_RESPONSE(&priv->ring, priv->ring.rsp_prod_pvt++);
> + rsp->req_id = req->req_id;
> + rsp->cmd = req->cmd;
> + rsp->u.connect.id = req->u.connect.id;
> + rsp->ret = ret;
> +
> + return 1;
> +}
> +
> +static int pvcalls_back_release_active(struct xenbus_device *dev,
> + struct pvcalls_back_priv *priv,
> + struct sock_mapping *map)
> +{
> return 0;
> }
>
> @@ -215,6 +355,11 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
> +{
> + return IRQ_HANDLED;
> +}
> +
> static int backend_connect(struct xenbus_device *dev)
> {
> int err, evtchn;
>

\
 
 \ /
  Last update: 2017-05-16 04:50    [W:0.172 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site