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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 9C5ADC433ED for ; Thu, 22 Apr 2021 11:42:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B5C161426 for ; Thu, 22 Apr 2021 11:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236099AbhDVLn3 (ORCPT ); Thu, 22 Apr 2021 07:43:29 -0400 Received: from mx13.kaspersky-labs.com ([91.103.66.164]:47901 "EHLO mx13.kaspersky-labs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235977AbhDVLn2 (ORCPT ); Thu, 22 Apr 2021 07:43:28 -0400 Received: from relay13.kaspersky-labs.com (unknown [127.0.0.10]) by relay13.kaspersky-labs.com (Postfix) with ESMTP id 8FCDB520CBB; Thu, 22 Apr 2021 14:41:29 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaspersky.com; s=mail202102; t=1619091689; bh=fPxpmo16E9UB1ApmTQaxclcEXs8/mubLz2lcg/RBltA=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type; b=AkdvolxTUK0V7F2tp40Scsh6XuKIy7XgCogrpyAAGa/dIFEcWbC4PWtreA88VLH8N UKNUYsd0AbLL3QnTqAVtDqsIbpsqQPqFLm3iSbrgvtZnFaJJOu+WQ/8u2ToWNw+Jtr jdQNfgJ0F4uZ6upZTg8w0gjzj1Ex+C466/cJaBW9i0nWg+IKvXbltyz+iM4oxt9zb+ mbRQCqJ+vbZVoc9fFg5ncmZ89Be+zy5qtwbYH1RXH5orfp02E7QjAbt6xNkjh3qDeS IAzJdUcjWz1f49a6BEe+QkQiDrxzDSJ0ONgmIPSlPg3zoICLbhTE7MKzuovM1K6tAA xshIzNfrr4Bgw== 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 92821520CBF; Thu, 22 Apr 2021 14:41:28 +0300 (MSK) Received: from [10.16.171.77] (10.64.68.128) 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, 22 Apr 2021 14:41:27 +0300 Subject: Re: [RFC PATCH v8 00/19] virtio/vsock: introduce SOCK_SEQPACKET support To: Stefano Garzarella CC: Stefan Hajnoczi , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Jakub Kicinski , Jorgen Hansen , Colin Ian King , Andra Paraschiv , Norbert Slusarek , Alexander Popov , "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: <20210413123954.3396314-1-arseny.krasnov@kaspersky.com> <20210421095213.25hnfi2th7gzyzt2@steredhat> <2c3d0749-0f41-e064-0153-b6130268add2@kaspersky.com> <20210422084638.bvblk33b4oi6cec6@steredhat> <20210422100217.jmpgevtrukqyukfo@steredhat> <20210422104813.e2p4wzuk2ahw7af7@steredhat> From: Arseny Krasnov Message-ID: <238339aa-83d2-694b-a73b-82c3887b6d86@kaspersky.com> Date: Thu, 22 Apr 2021 14:41:27 +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: <20210422104813.e2p4wzuk2ahw7af7@steredhat> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.64.68.128] 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: 04/22/2021 11:29:29 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 0 X-KSE-AntiSpam-Info: Lua profiles 163285 [Apr 22 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: 442 442 b985cb57763b61d2a20abb585d5d4cc10c315b09 X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: kaspersky.com:7.1.1;127.0.0.199:7.1.2;d41d8cd98f00b204e9800998ecf8427e.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: 04/22/2021 11:31:00 X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 22.04.2021 7:02:00 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: 2021/04/22 10:42:00 X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, bases: 2021/04/22 07:02:00 #16598851 X-KLMS-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 22.04.2021 13:48, Stefano Garzarella wrote: > On Thu, Apr 22, 2021 at 01:29:54PM +0300, Arseny Krasnov wrote: >> On 22.04.2021 13:02, Stefano Garzarella wrote: >>> On Thu, Apr 22, 2021 at 12:40:17PM +0300, Arseny Krasnov wrote: >>>> On 22.04.2021 11:46, Stefano Garzarella wrote: >>>>> On Wed, Apr 21, 2021 at 06:06:28PM +0300, Arseny Krasnov wrote: >>>>>> Thank You, i'll prepare next version. Main question is: does this >>>>>> approach(no SEQ_BEGIN, SEQ_END, 'msg_len' and 'msg_id') considered >>>>>> good? In this case it will be easier to prepare final version, because >>>>>> is smaller and more simple than previous logic. Also patch to spec >>>>>> will be smaller. >>>>> Yes, it's definitely much better than before. >>>>> >>>>> The only problem I see is that we add some overhead per fragment >>>>> (header). We could solve that with the mergeable buffers that Jiang is >>>>> considering for DGRAM. >>>> If we are talking about receive, i think, i can reuse merge logic for >>> Yep, for TX the guest can potentially enqueue a big buffer. >>> Maybe it's still worth keeping a maximum size and fragmenting as we do >>> now. >>> >>>> stream sockets, the only difference is that buffers are mergeable >>>> until previous EOR(e.g. previous message) bit is found in rx queue. >>>> >>> I got a little lost. >>> Can you elaborate more? >> I'm talking about 'virtio_transport_recv_enqueue()': it tries to copy >> >> data of new packet to buffer of tail packet in rx queue. In case of >> >> SEQPACKET i can reuse it, just adding logic that check EOR bit of >> >> tail packet. > This might be a good idea. > It doesn't save us the transmitted header though, but at least it saves > us from queuing it. > Even if with SEQPACKET I don't expect small packets, since it's the > driver that divides them and I think it does everything to use the > maximum available. > > Instead the mergeable buffers I was referring to are based on the > virito-net feature VIRTIO_NET_F_MRG_RXBUF. > Jiang is investigating whether we can reuse them for DGRAM. Understand, thank you > > Thanks, > Stefano > >