From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17F48C433ED for ; Thu, 13 May 2021 14:43:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E53D36135A for ; Thu, 13 May 2021 14:43:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234595AbhEMOpC (ORCPT ); Thu, 13 May 2021 10:45:02 -0400 Received: from mx13.kaspersky-labs.com ([91.103.66.164]:14889 "EHLO mx13.kaspersky-labs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234630AbhEMOoQ (ORCPT ); Thu, 13 May 2021 10:44:16 -0400 Received: from relay13.kaspersky-labs.com (unknown [127.0.0.10]) by relay13.kaspersky-labs.com (Postfix) with ESMTP id DD6D6521A48; Thu, 13 May 2021 17:42:59 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaspersky.com; s=mail202102; t=1620916980; bh=rrC7pB7ZvT9skg01jvxfGXAPzON2vylog2KME9ggwAg=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type; b=3QmIv7jjqLWHvcOfz6Q/41DWnTUmZ9uSF0AatbmEyFstDkU19KygWZUgF1BAhYwYl nJ8Qa3E/8Ut21rTQd3bYVv6Rg2zn71ZBu3BPRSwEmFCljAVMU4pJU01IxRYfHRXYIe iZOcwjsRJoBT464miKHP/vztNreeXn1l5Ob0RRES6is43frG1VRcXsTn+yE1Ura0q6 DdxTK2pFdmWoJ+g1F56rfFc5r+eAIAgTzWaVkSUxnRTijNIIic1ecMMCITiG/jCnU7 F19d6SaG7wBrkyVLx1MVGNhxaekqPC7+/W6hhpf0oun89eXcXNwIm5u6Y9BLeYs30V 8+ylbZ+el9s3w== Received: from mail-hq2.kaspersky.com (unknown [91.103.66.206]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client CN "mail-hq2.kaspersky.com", Issuer "Kaspersky MailRelays CA G3" (verified OK)) by mailhub13.kaspersky-labs.com (Postfix) with ESMTPS id 44D5752196F; Thu, 13 May 2021 17:42:57 +0300 (MSK) Received: from [10.16.171.77] (10.64.68.129) by hqmailmbx3.avp.ru (10.64.67.243) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 13 May 2021 17:42:48 +0300 Subject: Re: [RFC PATCH v9 11/19] virtio/vsock: dequeue callback for SOCK_SEQPACKET To: Stefano Garzarella CC: Stefan Hajnoczi , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Jakub Kicinski , Jorgen Hansen , Andra Paraschiv , Colin Ian King , Norbert Slusarek , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stsp2@yandex.ru" , "oxffffaa@gmail.com" References: <20210508163027.3430238-1-arseny.krasnov@kaspersky.com> <20210508163523.3431999-1-arseny.krasnov@kaspersky.com> <20210513115816.332nfej4jyra7vrh@steredhat> From: Arseny Krasnov Message-ID: Date: Thu, 13 May 2021 17:42:47 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210513115816.332nfej4jyra7vrh@steredhat> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.64.68.129] X-ClientProxiedBy: hqmailmbx1.avp.ru (10.64.67.241) To hqmailmbx3.avp.ru (10.64.67.243) X-KSE-ServerInfo: hqmailmbx3.avp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 5.9.20, Database issued on: 05/13/2021 14:30:02 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 0 X-KSE-AntiSpam-Info: Lua profiles 163644 [May 13 2021] X-KSE-AntiSpam-Info: Version: 5.9.20.0 X-KSE-AntiSpam-Info: Envelope from: arseny.krasnov@kaspersky.com X-KSE-AntiSpam-Info: LuaCore: 445 445 d5f7ae5578b0f01c45f955a2a751ac25953290c9 X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;kaspersky.com:7.1.1 X-KSE-AntiSpam-Info: Rate: 0 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Deterministic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 05/13/2021 14:33:00 X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 13.05.2021 13:39:00 X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-KLMS-Rule-ID: 52 X-KLMS-Message-Action: clean X-KLMS-AntiSpam-Status: not scanned, disabled by settings X-KLMS-AntiSpam-Interceptor-Info: not scanned X-KLMS-AntiPhishing: Clean, bases: 2021/05/13 13:03:00 X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, bases: 2021/05/13 10:44:00 #16575454 X-KLMS-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 13.05.2021 14:58, Stefano Garzarella wrote: > On Sat, May 08, 2021 at 07:35:20PM +0300, Arseny Krasnov wrote: >> This adds transport callback and it's logic for SEQPACKET dequeue. >> Callback fetches RW packets from rx queue of socket until whole record >> is copied(if user's buffer is full, user is not woken up). This is done >> to not stall sender, because if we wake up user and it leaves syscall, >> nobody will send credit update for rest of record, and sender will wait >> for next enter of read syscall at receiver's side. So if user buffer is >> full, we just send credit update and drop data. >> >> Signed-off-by: Arseny Krasnov >> --- >> v8 -> v9: >> 1) Check for RW packet type is removed from loop(all packet now >> considered RW). >> 2) Locking in loop is fixed. >> 3) cpu_to_le32()/le32_to_cpu() now used. >> 4) MSG_TRUNC handling removed from transport. >> >> include/linux/virtio_vsock.h | 5 ++ >> net/vmw_vsock/virtio_transport_common.c | 64 +++++++++++++++++++++++++ >> 2 files changed, 69 insertions(+) >> >> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >> index dc636b727179..02acf6e9ae04 100644 >> --- a/include/linux/virtio_vsock.h >> +++ b/include/linux/virtio_vsock.h >> @@ -80,6 +80,11 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk, >> struct msghdr *msg, >> size_t len, int flags); >> >> +ssize_t >> +virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, >> + struct msghdr *msg, >> + int flags, >> + bool *msg_ready); >> s64 virtio_transport_stream_has_data(struct vsock_sock *vsk); >> s64 virtio_transport_stream_has_space(struct vsock_sock *vsk); >> >> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c >> index ad0d34d41444..f649a21dd23b 100644 >> --- a/net/vmw_vsock/virtio_transport_common.c >> +++ b/net/vmw_vsock/virtio_transport_common.c >> @@ -393,6 +393,58 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, >> return err; >> } >> >> +static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, >> + struct msghdr *msg, >> + int flags, >> + bool *msg_ready) >> +{ >> + struct virtio_vsock_sock *vvs = vsk->trans; >> + struct virtio_vsock_pkt *pkt; >> + int err = 0; >> + size_t user_buf_len = msg->msg_iter.count; >> + >> + *msg_ready = false; >> + spin_lock_bh(&vvs->rx_lock); >> + >> + while (!*msg_ready && !list_empty(&vvs->rx_queue) && err >= 0) { >> + size_t bytes_to_copy; >> + size_t pkt_len; >> + >> + pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list); >> + pkt_len = (size_t)le32_to_cpu(pkt->hdr.len); >> + bytes_to_copy = min(user_buf_len, pkt_len); >> + >> + if (bytes_to_copy) { >> + /* 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); >> + >> + if (memcpy_to_msg(msg, pkt->buf, bytes_to_copy)) >> { >> + err = -EINVAL; >> + } else { >> + err += pkt_len; > If `bytes_to_copy == 0` we are not increasing the real length. > > Anyway is a bit confusing increase a variable called `err`, I think is > better to have another variable to store this information that we return > if there aren't errors. Ack > >