From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759300AbdEOUi3 (ORCPT ); Mon, 15 May 2017 16:38:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:58572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934798AbdEOUgS (ORCPT ); Mon, 15 May 2017 16:36:18 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F093F23983 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 12/18] xen/pvcalls: implement poll command Date: Mon, 15 May 2017 13:36:04 -0700 Message-Id: <1494880570-14209-12-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1494880570-14209-1-git-send-email-sstabellini@kernel.org> References: <1494880570-14209-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 70 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index d8e0a60..d5b7412 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -381,11 +381,30 @@ 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_back_priv *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; + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&priv->ring, notify); + if (notify) + notify_remote_via_irq(mappass->priv->irq); + } else + queue_work(mappass->wq, &mappass->register_work); + spin_unlock_irqrestore(&mappass->copy_lock, flags); } static int pvcalls_back_bind(struct xenbus_device *dev, @@ -534,6 +553,55 @@ static int pvcalls_back_accept(struct xenbus_device *dev, static int pvcalls_back_poll(struct xenbus_device *dev, struct xen_pvcalls_request *req) { + struct pvcalls_back_priv *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; + + if (dev == NULL) + return 0; + priv = dev_get_drvdata(&dev->dev); + + mappass = radix_tree_lookup(&priv->socketpass_mappings, req->u.poll.id); + if (mappass == NULL) + return 0; + + /* + * 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; + lock_sock(mappass->sock->sk); + icsk = inet_csk(mappass->sock->sk); + queue = &icsk->icsk_accept_queue; + data = queue->rskq_accept_head != NULL; + release_sock(mappass->sock->sk); + if (data) { + mappass->reqcopy.cmd = 0; + ret = 0; + goto out; + } + + return 0; + +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 0; } -- 1.9.1