Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751465AbdFBTdy (ORCPT ); Fri, 2 Jun 2017 15:33:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:56018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbdFBTcB (ORCPT ); Fri, 2 Jun 2017 15:32:01 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 291A223A30 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, sstabellini@kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, Stefano Stabellini Subject: [PATCH v3 12/18] xen/pvcalls: implement poll command Date: Fri, 2 Jun 2017 12:31:49 -0700 Message-Id: <1496431915-20774-12-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1496431915-20774-1-git-send-email-sstabellini@kernel.org> References: <1496431915-20774-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3489 Lines: 116 Implement poll on passive sockets by requesting a delayed response with mappass->reqcopy, and reply back when there is data on the passive socket. Poll on active socket is unimplemented as by the spec, as the frontend should just wait for events and check the indexes on the indexes page. Only support one outstanding poll (or accept) request for every passive socket at any given time. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 75 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 73 insertions(+), 2 deletions(-) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index f1173f4..82f350d 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -344,11 +344,33 @@ static void __pvcalls_back_accept(struct work_struct *work) static void pvcalls_pass_sk_data_ready(struct sock *sock) { struct sockpass_mapping *mappass = sock->sk_user_data; + struct pvcalls_fedata *priv; + struct xen_pvcalls_response *rsp; + unsigned long flags; + int notify; if (mappass == NULL) return; - queue_work(mappass->wq, &mappass->register_work); + priv = mappass->priv; + spin_lock_irqsave(&mappass->copy_lock, flags); + if (mappass->reqcopy.cmd == PVCALLS_POLL) { + rsp = RING_GET_RESPONSE(&priv->ring, priv->ring.rsp_prod_pvt++); + rsp->req_id = mappass->reqcopy.req_id; + rsp->u.poll.id = mappass->reqcopy.u.poll.id; + rsp->cmd = mappass->reqcopy.cmd; + rsp->ret = 0; + + mappass->reqcopy.cmd = 0; + spin_unlock_irqrestore(&mappass->copy_lock, flags); + + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&priv->ring, notify); + if (notify) + notify_remote_via_irq(mappass->priv->irq); + } else { + spin_unlock_irqrestore(&mappass->copy_lock, flags); + queue_work(mappass->wq, &mappass->register_work); + } } static int pvcalls_back_bind(struct xenbus_device *dev, @@ -493,7 +515,56 @@ static int pvcalls_back_accept(struct xenbus_device *dev, static int pvcalls_back_poll(struct xenbus_device *dev, struct xen_pvcalls_request *req) { - return 0; + struct pvcalls_fedata *priv; + struct sockpass_mapping *mappass; + struct xen_pvcalls_response *rsp; + struct inet_connection_sock *icsk; + struct request_sock_queue *queue; + unsigned long flags; + int ret; + bool data; + + priv = dev_get_drvdata(&dev->dev); + + mappass = radix_tree_lookup(&priv->socketpass_mappings, req->u.poll.id); + if (mappass == NULL) + return -EINVAL; + + /* + * Limitation of the current implementation: only support one + * concurrent accept or poll call on one socket. + */ + spin_lock_irqsave(&mappass->copy_lock, flags); + if (mappass->reqcopy.cmd != 0) { + ret = -EINTR; + goto out; + } + + mappass->reqcopy = *req; + icsk = inet_csk(mappass->sock->sk); + queue = &icsk->icsk_accept_queue; + spin_lock(&queue->rskq_lock); + data = queue->rskq_accept_head != NULL; + spin_unlock(&queue->rskq_lock); + if (data) { + mappass->reqcopy.cmd = 0; + ret = 0; + goto out; + } + spin_unlock_irqrestore(&mappass->copy_lock, flags); + + /* Tell the caller we don't need to send back a notification yet */ + return -1; + +out: + spin_unlock_irqrestore(&mappass->copy_lock, flags); + + rsp = RING_GET_RESPONSE(&priv->ring, priv->ring.rsp_prod_pvt++); + rsp->req_id = req->req_id; + rsp->cmd = req->cmd; + rsp->u.poll.id = req->u.poll.id; + rsp->ret = ret; + return ret; } static int pvcalls_back_handle_cmd(struct xenbus_device *dev, -- 1.9.1