From patchwork Sat Oct 7 00:30:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 9990903 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 977E460364 for ; Sat, 7 Oct 2017 00:33:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8947428DF7 for ; Sat, 7 Oct 2017 00:33:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E30828E2B; Sat, 7 Oct 2017 00:33:01 +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 EB7A128DF7 for ; Sat, 7 Oct 2017 00:33:00 +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 1e0d0o-0003Dq-57; Sat, 07 Oct 2017 00:30:38 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e0d0m-00039k-6o for xen-devel@lists.xen.org; Sat, 07 Oct 2017 00:30:36 +0000 Received: from [85.158.137.68] by server-4.bemta-3.messagelabs.com id E2/B5-02227-B2028D95; Sat, 07 Oct 2017 00:30:35 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgkeJIrShJLcpLzFFi42I5NlE2WVdT4Ua kwee9phZLPi5mcWD0OLr7N1MAYxRrZl5SfkUCa8bxfw4F91UrVjy9ydrAeE++i5GLQ0hgHZPE xH+T2LsYOTlYBBwkpi38ytTFyMHBKBAj8eCHNUiYUSBMYvLlJawgNpuAocTfJ5vYQGwRAWmJa 58vM4LMYRaYzCjx+t0vZpCEsICFxP+5IAmQmaoSR+fPB2vgFXCT6Hy7F6xGQkBO4uSxyWBDOQ XcJQ4t/MQEcVAbo8SlcxtYJzDyLmBkWMWoUZxaVJZapGtkoJdUlJmeUZKbmJmja2hgrJebWly cmJ6ak5hUrJecn7uJERgO9QwMjDsYm0/4HWKU5GBSEuV1krsRKcSXlJ9SmZFYnBFfVJqTWnyI UYaDQ0mCt1MeKCdYlJqeWpGWmQMMTJi0BAePkgjvX5BW3uKCxNzizHSI1ClGY45jmy7/YeLou Hn3D5MQS15+XqqUOG8SyCQBkNKM0jy4QbCIucQoKyXMy8jAwCDEU5BalJtZgir/ilGcg1FJmP cGyEKezLwSuH2vgE5hAjplTtMVkFNKEhFSUg2MwpJvP2Yxr9M4bM7CeyPF+t/dpMfuHQd1rzD d6jPWqHgt5BsperPor2egT5HP1UeRq6/c+bwt63tDqWyN90PVpe8DBKbz8z+LCdLoEViocmvR m6k9FrPmfF2s/sp+x8kr4SWbP7wJl/4Yy+HU23LhkmLxAV3ppu7kS3d1GroOpmZM7tK6njpDi aU4I9FQi7moOBEAX6O4SpMCAAA= X-Env-Sender: sstabellini@kernel.org X-Msg-Ref: server-4.tower-31.messagelabs.com!1507336232!51083418!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 8857 invoked from network); 7 Oct 2017 00:30:33 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.99) by server-4.tower-31.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 7 Oct 2017 00:30:33 -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 0600D2190E; Sat, 7 Oct 2017 00:30:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0600D2190E From: Stefano Stabellini To: xen-devel@lists.xen.org Date: Fri, 6 Oct 2017 17:30:23 -0700 Message-Id: <1507336227-20477-9-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1507336227-20477-1-git-send-email-sstabellini@kernel.org> References: <1507336227-20477-1-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 v5 09/13] xen/pvcalls: implement sendmsg 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 Send data to an active socket by copying data to the "out" ring. Take the active socket out_mutex so that only one function can access the ring at any given time. If not enough room is available on the ring, rather than returning immediately or sleep-waiting, spin for up to 5000 cycles. This small optimization turns out to improve performance significantly. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-front.c | 118 ++++++++++++++++++++++++++++++++++++++++++++ drivers/xen/pvcalls-front.h | 3 ++ 2 files changed, 121 insertions(+) diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 8958e74..c13c40a 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -29,6 +29,7 @@ #define PVCALLS_INVALID_ID UINT_MAX #define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER #define PVCALLS_NR_REQ_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) +#define PVCALLS_FRONT_MAX_SPIN 5000 struct pvcalls_bedata { struct xen_pvcalls_front_ring ring; @@ -100,6 +101,23 @@ static inline int get_request(struct pvcalls_bedata *bedata, int *req_id) return 0; } +static bool pvcalls_front_write_todo(struct sock_mapping *map) +{ + struct pvcalls_data_intf *intf = map->active.ring; + RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + error = intf->out_error; + if (error == -ENOTCONN) + return false; + if (error != 0) + return true; + + cons = intf->out_cons; + prod = intf->out_prod; + return !!(size - pvcalls_queued(prod, cons, size)); +} + static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) { struct xenbus_device *dev = dev_id; @@ -364,6 +382,106 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, return ret; } +static int __write_ring(struct pvcalls_data_intf *intf, + struct pvcalls_data *data, + struct iov_iter *msg_iter, + int len) +{ + RING_IDX cons, prod, size, masked_prod, masked_cons; + RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + error = intf->out_error; + if (error < 0) + return error; + cons = intf->out_cons; + prod = intf->out_prod; + /* read indexes before continuing */ + virt_mb(); + + size = pvcalls_queued(prod, cons, array_size); + if (size >= array_size) + return 0; + if (len > array_size - size) + len = array_size - size; + + masked_prod = pvcalls_mask(prod, array_size); + masked_cons = pvcalls_mask(cons, array_size); + + if (masked_prod < masked_cons) { + copy_from_iter(data->out + masked_prod, len, msg_iter); + } else { + if (len > array_size - masked_prod) { + copy_from_iter(data->out + masked_prod, + array_size - masked_prod, msg_iter); + copy_from_iter(data->out, + len - (array_size - masked_prod), + msg_iter); + } else { + copy_from_iter(data->out + masked_prod, len, msg_iter); + } + } + /* write to ring before updating pointer */ + virt_wmb(); + intf->out_prod += len; + + return len; +} + +int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, + size_t len) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + int sent, tot_sent = 0; + int count = 0, flags; + + flags = msg->msg_flags; + if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB)) + 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.out_mutex); + if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) { + mutex_unlock(&map->active.out_mutex); + pvcalls_exit(); + return -EAGAIN; + } + if (len > INT_MAX) + len = INT_MAX; + +again: + count++; + sent = __write_ring(map->active.ring, + &map->active.data, &msg->msg_iter, + len); + if (sent > 0) { + len -= sent; + tot_sent += sent; + notify_remote_via_irq(map->active.irq); + } + if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN) + goto again; + if (sent < 0) + tot_sent = sent; + + mutex_unlock(&map->active.out_mutex); + pvcalls_exit(); + return tot_sent; +} + 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 ab4f1da..d937c24 100644 --- a/drivers/xen/pvcalls-front.h +++ b/drivers/xen/pvcalls-front.h @@ -13,5 +13,8 @@ int pvcalls_front_bind(struct socket *sock, int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags); +int pvcalls_front_sendmsg(struct socket *sock, + struct msghdr *msg, + size_t len); #endif