From patchwork Sat Jul 1 06:39:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arseniy Krasnov X-Patchwork-Id: 13298933 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C72DEB64DC for ; Sat, 1 Jul 2023 06:52:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230297AbjGAGwm (ORCPT ); Sat, 1 Jul 2023 02:52:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230028AbjGAGvb (ORCPT ); Sat, 1 Jul 2023 02:51:31 -0400 Received: from mx1.sberdevices.ru (mx2.sberdevices.ru [45.89.224.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2EE5729A; Fri, 30 Jun 2023 23:45:20 -0700 (PDT) Received: from p-infra-ksmg-sc-msk02 (localhost [127.0.0.1]) by mx1.sberdevices.ru (Postfix) with ESMTP id 401DD120003; Sat, 1 Jul 2023 09:45:03 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.sberdevices.ru 401DD120003 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sberdevices.ru; s=mail; t=1688193903; bh=KtR+snAmemDx/QdrmLGfvVQlJ5kcP+i64AE/km7ksjQ=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=hskLGhZ32n+AarXCk6+GzLEK5viAJVyZaGEe7NDk2wndlrNWqCUrTYg4KcUPxyF/+ dZyaN1vWct8n2T5/IOgwcxciL0bl79MG7KcvyvcQRO2yXD2KEQOaMQP65u8gfPgBUy ffpfA6WreuslxdS01EVv0mwk0vurbz7w7FMsnQOR7oV2wPpN5+/mU6fMCiU7wJ6kgp 3fLmanZVQSKZRFqY9YSR3Jto/kaj0iKfMqRIYzWkOhBQJsRd3rRRrkK/PtRIjksXA1 AaEx5//LYoMiGjZg3euinFs28pU83Ryuyts51pfhHvzpkx1gb4qRqY0WIdR5OdiAZD bH05C3wCMA26w== Received: from p-i-exch-sc-m01.sberdevices.ru (p-i-exch-sc-m01.sberdevices.ru [172.16.192.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.sberdevices.ru (Postfix) with ESMTPS; Sat, 1 Jul 2023 09:45:02 +0300 (MSK) Received: from localhost.localdomain (100.64.160.123) by p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.30; Sat, 1 Jul 2023 09:44:43 +0300 From: Arseniy Krasnov To: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Jason Wang , Bobby Eshleman CC: , , , , , , , Arseniy Krasnov Subject: [RFC PATCH v5 01/17] vsock/virtio: read data from non-linear skb Date: Sat, 1 Jul 2023 09:39:31 +0300 Message-ID: <20230701063947.3422088-2-AVKrasnov@sberdevices.ru> X-Mailer: git-send-email 2.35.0 In-Reply-To: <20230701063947.3422088-1-AVKrasnov@sberdevices.ru> References: <20230701063947.3422088-1-AVKrasnov@sberdevices.ru> MIME-Version: 1.0 X-Originating-IP: [100.64.160.123] X-ClientProxiedBy: p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) To p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) X-KSMG-Rule-ID: 10 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 178380 [Jun 30 2023] X-KSMG-AntiSpam-Version: 5.9.59.0 X-KSMG-AntiSpam-Envelope-From: AVKrasnov@sberdevices.ru X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 517 517 b0056c19d8e10afbb16cb7aad7258dedb0179a79, {Tracking_from_domain_doesnt_match_to}, sberdevices.ru:7.1.1,5.0.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;100.64.160.123:7.1.2;p-i-exch-sc-m01.sberdevices.ru:7.1.1,5.0.1, FromAlignment: s, {Tracking_white_helo}, ApMailHostAddress: 100.64.160.123 X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean X-KSMG-LinksScanning: Clean X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2023/07/01 04:02:00 #21597763 X-KSMG-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This is preparation patch for non-linear skbuff handling. It replaces direct calls of 'memcpy_to_msg()' with 'skb_copy_datagram_iter()'. Main advantage of the second one is that is can handle paged part of the skb by using 'kmap()' on each page, but if there are no pages in the skb, it behaves like simple copying to iov iterator. This patch also adds new field to the control block of skb - this value shows current offset in the skb to read next portion of data (it doesn't matter linear it or not). Idea is that 'skb_copy_datagram_iter()' handles both types of skb internally - it just needs an offset from which to copy data from the given skb. This offset is incremented on each read from skb. This approach allows to avoid special handling of non-linear skbs: 1) We can't call 'skb_pull()' on it, because it updates 'data' pointer. 2) We need to update 'data_len' also on each read from this skb. Signed-off-by: Arseniy Krasnov --- Changelog: v4 -> v5: * Use local variable for 'frag_off' in stream dequeue calback. * R-b from Bobby Eshleman removed due to patch update. include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport_common.c | 30 ++++++++++++++++++------- 2 files changed, 23 insertions(+), 8 deletions(-) diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index c58453699ee9..17dbb7176e37 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -12,6 +12,7 @@ struct virtio_vsock_skb_cb { bool reply; bool tap_delivered; + u32 frag_off; }; #define VIRTIO_VSOCK_SKB_CB(skb) ((struct virtio_vsock_skb_cb *)((skb)->cb)) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index b769fc258931..e5683af23e60 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -355,7 +355,7 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk, spin_lock_bh(&vvs->rx_lock); skb_queue_walk_safe(&vvs->rx_queue, skb, tmp) { - off = 0; + off = VIRTIO_VSOCK_SKB_CB(skb)->frag_off; if (total == len) break; @@ -370,7 +370,10 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk, */ spin_unlock_bh(&vvs->rx_lock); - err = memcpy_to_msg(msg, skb->data + off, bytes); + err = skb_copy_datagram_iter(skb, off, + &msg->msg_iter, + bytes); + if (err) goto out; @@ -411,27 +414,35 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, } while (total < len && !skb_queue_empty(&vvs->rx_queue)) { + u32 skb_rest_len; + skb = skb_peek(&vvs->rx_queue); bytes = len - total; - if (bytes > skb->len) - bytes = skb->len; + skb_rest_len = skb->len - VIRTIO_VSOCK_SKB_CB(skb)->frag_off; + + if (bytes > skb_rest_len) + bytes = skb_rest_len; /* sk_lock is held by caller so no one else can dequeue. * Unlock rx_lock since memcpy_to_msg() may sleep. */ spin_unlock_bh(&vvs->rx_lock); - err = memcpy_to_msg(msg, skb->data, bytes); + err = skb_copy_datagram_iter(skb, + VIRTIO_VSOCK_SKB_CB(skb)->frag_off, + &msg->msg_iter, bytes); + if (err) goto out; spin_lock_bh(&vvs->rx_lock); total += bytes; - skb_pull(skb, bytes); - if (skb->len == 0) { + VIRTIO_VSOCK_SKB_CB(skb)->frag_off += bytes; + + if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->frag_off) { u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len); virtio_transport_dec_rx_pkt(vvs, pkt_len); @@ -503,7 +514,10 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, */ spin_unlock_bh(&vvs->rx_lock); - err = memcpy_to_msg(msg, skb->data, bytes_to_copy); + err = skb_copy_datagram_iter(skb, 0, + &msg->msg_iter, + bytes_to_copy); + if (err) { /* Copy of message failed. Rest of * fragments will be freed without copy.