From 5db4d286a8ef88a04247a005df9cdd4bce3c7673 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Thu, 6 Jul 2017 11:01:06 -0700 Subject: [PATCH] xen/pvcalls: implement connect command 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. Allocate a workqueue and a work_struct, called ioworker, to perform reads and writes to the socket. 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 and pvcalls_back_ioworker will be implemented later. [ boris: fixed whitespaces ] Signed-off-by: Stefano Stabellini Reviewed-by: Juergen Gross CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky --- drivers/xen/pvcalls-back.c | 179 +++++++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index 8f436e51053a..c0fc774221ca 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -54,6 +54,39 @@ struct pvcalls_fedata { struct semaphore socket_lock; }; +struct pvcalls_ioworker { + struct work_struct register_work; + struct workqueue_struct *wq; +}; + +struct sock_mapping { + struct list_head list; + struct pvcalls_fedata *fedata; + struct socket *sock; + 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 io; + atomic_t release; + void (*saved_data_ready)(struct sock *sk); + struct pvcalls_ioworker ioworker; +}; + +static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map); +static int pvcalls_back_release_active(struct xenbus_device *dev, + struct pvcalls_fedata *fedata, + struct sock_mapping *map); + +static void pvcalls_back_ioworker(struct work_struct *work) +{ +} + static int pvcalls_back_socket(struct xenbus_device *dev, struct xen_pvcalls_request *req) { @@ -82,8 +115,149 @@ static int pvcalls_back_socket(struct xenbus_device *dev, return 0; } +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 struct sock_mapping *pvcalls_new_active_socket( + struct pvcalls_fedata *fedata, + uint64_t id, + grant_ref_t ref, + uint32_t evtchn, + struct socket *sock) +{ + int ret; + struct sock_mapping *map; + void *page; + + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (map == NULL) + return NULL; + + map->fedata = fedata; + map->sock = sock; + map->id = id; + map->ref = ref; + + ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page); + if (ret < 0) + goto out; + map->ring = page; + map->ring_order = map->ring->ring_order; + /* first read the order, then map the data ring */ + virt_rmb(); + if (map->ring_order > MAX_RING_ORDER) { + pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n", + __func__, map->ring_order, MAX_RING_ORDER); + goto out; + } + ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref, + (1 << map->ring_order), &page); + if (ret < 0) + goto out; + map->bytes = page; + + ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id, + evtchn, + pvcalls_back_conn_event, + 0, + "pvcalls-backend", + map); + if (ret < 0) + goto out; + map->irq = ret; + + map->data.in = map->bytes; + map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order); + + map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1); + if (!map->ioworker.wq) + goto out; + atomic_set(&map->io, 1); + INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker); + + down(&fedata->socket_lock); + list_add_tail(&map->list, &fedata->socket_mappings); + up(&fedata->socket_lock); + + write_lock_bh(&map->sock->sk->sk_callback_lock); + map->saved_data_ready = map->sock->sk->sk_data_ready; + map->sock->sk->sk_user_data = map; + map->sock->sk->sk_data_ready = pvcalls_sk_data_ready; + map->sock->sk->sk_state_change = pvcalls_sk_state_change; + write_unlock_bh(&map->sock->sk->sk_callback_lock); + + return map; +out: + down(&fedata->socket_lock); + list_del(&map->list); + pvcalls_back_release_active(fedata->dev, fedata, map); + up(&fedata->socket_lock); + return NULL; +} + static int pvcalls_back_connect(struct xenbus_device *dev, struct xen_pvcalls_request *req) +{ + struct pvcalls_fedata *fedata; + int ret = -EINVAL; + struct socket *sock; + struct sock_mapping *map; + struct xen_pvcalls_response *rsp; + struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr; + + fedata = dev_get_drvdata(&dev->dev); + + if (req->u.connect.len < sizeof(sa->sa_family) || + req->u.connect.len > sizeof(req->u.connect.addr) || + sa->sa_family != AF_INET) + goto out; + + ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock); + if (ret < 0) + goto out; + ret = inet_stream_connect(sock, sa, req->u.connect.len, 0); + if (ret < 0) { + sock_release(sock); + goto out; + } + + map = pvcalls_new_active_socket(fedata, + req->u.connect.id, + req->u.connect.ref, + req->u.connect.evtchn, + sock); + if (!map) { + ret = -EFAULT; + sock_release(map->sock); + } + +out: + rsp = RING_GET_RESPONSE(&fedata->ring, fedata->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 0; +} + +static int pvcalls_back_release_active(struct xenbus_device *dev, + struct pvcalls_fedata *fedata, + struct sock_mapping *map) { return 0; } @@ -206,6 +380,11 @@ 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; -- 2.20.1