From patchwork Mon Oct 30 22:41:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 10033425 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 28AB26039A for ; Mon, 30 Oct 2017 22:43:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1AFD128650 for ; Mon, 30 Oct 2017 22:43:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0FCA028981; Mon, 30 Oct 2017 22:43:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7E9BF28650 for ; Mon, 30 Oct 2017 22:43:29 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e9Ik4-00055y-UR; Mon, 30 Oct 2017 22:41:12 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e9Ik3-00052o-Fc for xen-devel@lists.xen.org; Mon, 30 Oct 2017 22:41:11 +0000 Received: from [85.158.139.211] by server-2.bemta-5.messagelabs.com id 8A/E4-23269-68AA7F95; Mon, 30 Oct 2017 22:41:10 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmplkeJIrShJLcpLzFFi42I5NlE2Wbdt1fd Igz83mCyWfFzM4sDocXT3b6YAxijWzLyk/IoE1owzl7+wFOxUrljy+zt7A+N12S5GLg4hgXVM EtfOtrN1MXJwsAg4SPycngRiMgrESDz4Yd3FyAlkhklMvryEFcRmEzCU+PtkExuILSIgLXHt8 2VGkDHMApMZJV6/+8UMkhAWsJCYuL6RHWKkqsT+tdwgYV4Bd4nlzW/YQWwJATmJk8cmg83kBI r/eLmWCeKcNkaJzbOPME9g5F3AyLCKUaM4tagstUjX0EgvqSgzPaMkNzEzR9fQwFQvN7W4ODE 9NScxqVgvOT93EyMwGBiAYAdj3yznQ4ySHExKorw7Hb9HCvEl5adUZiQWZ8QXleakFh9ilOHg UJLgrVwJlBMsSk1PrUjLzAGGJUxagoNHSYT3ygqgNG9xQWJucWY6ROoUoyXHsU2X/zBxdNy8C ySfzXzdwCzEkpeflyolzhsIMk8ApCGjNA9uHCx2LjHKSgnzMgIdKMRTkFqUm1mCKv+KUZyDUU mYNwpkCk9mXgnc1ldABzEBHaQh+QXkoJJEhJRUAyPD1QWBjyL3rJ8ifT1vzpJXy6YfOL+CqzL ARkD/SmTmjebDUuq7HqWur/7eyVGo8V1XNMPuxm+xsukWtb4/S362BK10C7sfLOfLKyUll/F4 QeJe9dWPLjDmSqUHfz2W1nrunrGBWZQO77N6JkGF09WavPxJalNmSbqwCX8Jtr29VqxI3mvhJ yWW4oxEQy3mouJEAMZIdoKYAgAA X-Env-Sender: sstabellini@kernel.org X-Msg-Ref: server-6.tower-206.messagelabs.com!1509403268!106527100!1 X-Originating-IP: [198.145.29.99] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.4.45; banners=-,-,- X-VirusChecked: Checked Received: (qmail 53615 invoked from network); 30 Oct 2017 22:41:09 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.99) by server-6.tower-206.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 30 Oct 2017 22:41:09 -0000 Received: from localhost.localdomain (162-198-228-33.lightspeed.wlfrct.sbcglobal.net [162.198.228.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4493B21958; Mon, 30 Oct 2017 22:41:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4493B21958 From: Stefano Stabellini To: xen-devel@lists.xen.org Date: Mon, 30 Oct 2017 15:41:00 -0700 Message-Id: <1509403263-15414-10-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1509403263-15414-1-git-send-email-sstabellini@kernel.org> References: <1509403263-15414-1-git-send-email-sstabellini@kernel.org> Cc: jgross@suse.com, Stefano Stabellini , boris.ostrovsky@oracle.com, sstabellini@kernel.org, linux-kernel@vger.kernel.org Subject: [Xen-devel] [PATCH v8 10/13] xen/pvcalls: implement recvmsg X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Implement recvmsg by copying data from the "in" ring. If not enough data is available and the recvmsg call is blocking, then wait on the inflight_conn_req waitqueue. Take the active socket in_mutex so that only one function can access the ring at any given time. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-front.c | 111 ++++++++++++++++++++++++++++++++++++++++++++ drivers/xen/pvcalls-front.h | 4 ++ 2 files changed, 115 insertions(+) diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 7672578..24ffdc9 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -117,6 +117,20 @@ static bool pvcalls_front_write_todo(struct sock_mapping *map) return !!(size - pvcalls_queued(prod, cons, size)); } +static bool pvcalls_front_read_todo(struct sock_mapping *map) +{ + struct pvcalls_data_intf *intf = map->active.ring; + RING_IDX cons, prod; + int32_t error; + + cons = intf->in_cons; + prod = intf->in_prod; + error = intf->in_error; + return (error != 0 || + pvcalls_queued(prod, cons, + XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0); +} + static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) { struct xenbus_device *dev = dev_id; @@ -484,6 +498,103 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, return tot_sent; } +static int __read_ring(struct pvcalls_data_intf *intf, + struct pvcalls_data *data, + struct iov_iter *msg_iter, + size_t len, int flags) +{ + RING_IDX cons, prod, size, masked_prod, masked_cons; + RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + cons = intf->in_cons; + prod = intf->in_prod; + error = intf->in_error; + /* get pointers before reading from the ring */ + virt_rmb(); + if (error < 0) + return error; + + size = pvcalls_queued(prod, cons, array_size); + masked_prod = pvcalls_mask(prod, array_size); + masked_cons = pvcalls_mask(cons, array_size); + + if (size == 0) + return 0; + + if (len > size) + len = size; + + if (masked_prod > masked_cons) { + len = copy_to_iter(data->in + masked_cons, len, msg_iter); + } else { + if (len > (array_size - masked_cons)) { + int ret = copy_to_iter(data->in + masked_cons, + array_size - masked_cons, msg_iter); + if (ret != array_size - masked_cons) { + len = ret; + goto out; + } + len = ret + copy_to_iter(data->in, len - ret, msg_iter); + } else { + len = copy_to_iter(data->in + masked_cons, len, msg_iter); + } + } +out: + /* read data from the ring before increasing the index */ + virt_mb(); + if (!(flags & MSG_PEEK)) + intf->in_cons += len; + + return len; +} + +int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, + int flags) +{ + struct pvcalls_bedata *bedata; + int ret; + struct sock_mapping *map; + + if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC)) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + mutex_lock(&map->active.in_mutex); + if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) + len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + + while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) { + wait_event_interruptible(map->active.inflight_conn_req, + pvcalls_front_read_todo(map)); + } + ret = __read_ring(map->active.ring, &map->active.data, + &msg->msg_iter, len, flags); + + if (ret > 0) + notify_remote_via_irq(map->active.irq); + if (ret == 0) + ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0; + if (ret == -ENOTCONN) + ret = 0; + + mutex_unlock(&map->active.in_mutex); + pvcalls_exit(); + return ret; +} + int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len) { struct pvcalls_bedata *bedata; diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h index d937c24..de24041 100644 --- a/drivers/xen/pvcalls-front.h +++ b/drivers/xen/pvcalls-front.h @@ -16,5 +16,9 @@ int pvcalls_front_accept(struct socket *sock, int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, size_t len); +int pvcalls_front_recvmsg(struct socket *sock, + struct msghdr *msg, + size_t len, + int flags); #endif