Send PVCALLS_BIND to the backend. Introduce a new structure, part of
struct sock_mapping, to store information specific to passive sockets.
Introduce a status field to keep track of the status of the passive
socket.
Introduce a waitqueue for the "accept" command (see the accept command
implementation): it is used to allow only one outstanding accept
command at any given time and to implement polling on the passive
socket. Introduce a flags field to keep track of in-flight accept and
poll commands.
sock->sk->sk_send_head is not used for ip sockets: reuse the field to
store a pointer to the struct sock_mapping corresponding to the socket.
Convert the struct socket pointer into an uint64_t and use it as id for
the socket to pass to the backend.
Signed-off-by: Stefano Stabellini <stef...@aporeto.com>
CC: boris.ostrov...@oracle.com
CC: jgr...@suse.com
---
drivers/xen/pvcalls-front.c | 74 +++++++++++++++++++++++++++++++++++++++++++++
drivers/xen/pvcalls-front.h | 3 ++
2 files changed, 77 insertions(+)
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 0d305e0..71619bc 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -57,6 +57,23 @@ struct sock_mapping {
wait_queue_head_t inflight_conn_req;
} active;
+ struct {
+ /* Socket status */
+#define PVCALLS_STATUS_UNINITALIZED 0
+#define PVCALLS_STATUS_BIND 1
+#define PVCALLS_STATUS_LISTEN 2
+ uint8_t status;
+ /*
+ * Internal state-machine flags.
+ * Only one accept operation can be inflight for a socket.
+ * Only one poll operation can be inflight for a given socket.
+ */
+#define PVCALLS_FLAG_ACCEPT_INFLIGHT 0
+#define PVCALLS_FLAG_POLL_INFLIGHT 1
+#define PVCALLS_FLAG_POLL_RET 2
+ uint8_t flags;
+ wait_queue_head_t inflight_accept_req;
+ } passive;
};
};
@@ -287,6 +304,63 @@ int pvcalls_front_connect(struct socket *sock, struct
sockaddr *addr,
return ret;
}
+int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int
addr_len)
+{
+ struct pvcalls_bedata *bedata;
+ struct sock_mapping *map = NULL;
+ struct xen_pvcalls_request *req;
+ int notify, req_id, ret;
+
+ if (!pvcalls_front_dev)
+ return -ENOTCONN;
+ if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
+ return -ENOTSUPP;
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
+
+ map = kzalloc(sizeof(*map), GFP_KERNEL);
+ if (map == NULL)
+ return -ENOMEM;
+
+ 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);
+ if (RING_FULL(&bedata->ring) ||
+ READ_ONCE(bedata->rsp[req_id].req_id) != PVCALLS_INVALID_ID) {
+ kfree(map);
+ spin_unlock(&bedata->pvcallss_lock);
+ return -EAGAIN;
+ }
+ req = RING_GET_REQUEST(&bedata->ring, req_id);
+ req->req_id = req_id;
+ map->sock = sock;
+ req->cmd = PVCALLS_BIND;
+ req->u.bind.id = (uint64_t) sock;
+ memcpy(req->u.bind.addr, addr, sizeof(*addr));
+ req->u.bind.len = addr_len;
+
+ init_waitqueue_head(&map->passive.inflight_accept_req);
+
+ list_add_tail(&map->list, &bedata->socketpass_mappings);
+ WRITE_ONCE(sock->sk->sk_send_head, (void *)map);
+ map->active_socket = false;
+
+ 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_BIND;
+ 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 0;
+}
+
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 63b0417..8b0a274 100644
--- a/drivers/xen/pvcalls-front.h
+++ b/drivers/xen/pvcalls-front.h
@@ -6,5 +6,8 @@
int pvcalls_front_socket(struct socket *sock);
int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
int addr_len, int flags);
+int pvcalls_front_bind(struct socket *sock,
+ struct sockaddr *addr,
+ int addr_len);
#endif
--
1.9.1
