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=-17.3 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=unavailable 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 CD3A8C43460 for ; Wed, 21 Apr 2021 14:49:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8422A613CE for ; Wed, 21 Apr 2021 14:49:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243647AbhDUOuX (ORCPT ); Wed, 21 Apr 2021 10:50:23 -0400 Received: from mx12.kaspersky-labs.com ([91.103.66.155]:25938 "EHLO mx12.kaspersky-labs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238737AbhDUOuV (ORCPT ); Wed, 21 Apr 2021 10:50:21 -0400 Received: from relay12.kaspersky-labs.com (unknown [127.0.0.10]) by relay12.kaspersky-labs.com (Postfix) with ESMTP id 0E9F075F59; Wed, 21 Apr 2021 17:49:46 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaspersky.com; s=mail202102; t=1619016586; bh=uGLbHQ8wicSj1pcDH06ehK7pFuDpyXZSs5atyDJdx+Y=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type; b=O2MM7z6XCp8u92hXxTYLpwYZj6lJuBDwmUYS/ctZ2EU81sZRWhyskGczTegxi+Ywj uRmDMSDzxvwpyN2QZ2FJYBBB715d3b0sRRs0InPVrQZ50B+5f5V6buLPQu+6EJEFPJ BZuA8CuZC2FHpzU4pneLnUh5KAqWIDpt86VWhXz1lRGJVjLYU2TgQmAbHfkOIw1cZg PrnJOO7hgUWKjZywBHCkUrUOdt+I12LioucSTKLwcNhscMGCw3vMjbYa+LXoHZJrBQ 4mQxPaTXA/mdQxvzqYBwA63kfAcXGIWb6c2Bg1wIH5UCCV8coHHNU39Xslsz0tu3xX gPALXIqYo3ukw== 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 mailhub12.kaspersky-labs.com (Postfix) with ESMTPS id 16D3275F35; Wed, 21 Apr 2021 17:49:45 +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; Wed, 21 Apr 2021 17:49:44 +0300 Subject: Re: [RFC PATCH v8 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 , Jeff Vander Stoep , Alexander Popov , kvm , Linux Virtualization , netdev , kernel list , stsp , Krasnov Arseniy References: <20210413123954.3396314-1-arseny.krasnov@kaspersky.com> <20210413124443.3403382-1-arseny.krasnov@kaspersky.com> From: Arseny Krasnov Message-ID: <51549e2a-f549-e860-67f4-dd06b8922c5c@kaspersky.com> Date: Wed, 21 Apr 2021 17:49:44 +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: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.64.68.128] X-ClientProxiedBy: hqmailmbx2.avp.ru (10.64.67.242) 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: 04/21/2021 14:29:29 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 0 X-KSE-AntiSpam-Info: Lua profiles 163270 [Apr 21 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: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;kaspersky.com:7.1.1;127.0.0.199:7.1.2 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: 04/21/2021 14:32:00 X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 21.04.2021 11:31:00 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: 2021/04/21 13:40:00 X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, bases: 2021/04/21 11:31:00 #16604789 X-KLMS-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21.04.2021 11:56, Stefano Garzarella wrote: > On Tue, Apr 13, 2021 at 03:44:40PM +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 >> --- >> v7 -> v8: >> - Things like SEQ_BEGIN, SEQ_END, 'msg_len' and 'msg_id' now removed. >> This callback fetches and copies RW packets to user's buffer, until >> last packet of message found(this packet is marked in 'flags' field >> of header). >> >> include/linux/virtio_vsock.h | 5 ++ >> net/vmw_vsock/virtio_transport_common.c | 73 +++++++++++++++++++++++++ >> 2 files changed, 78 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 833104b71a1c..8492b8bd5df5 100644 >> --- a/net/vmw_vsock/virtio_transport_common.c >> +++ b/net/vmw_vsock/virtio_transport_common.c >> @@ -393,6 +393,67 @@ 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) { >> + pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list); >> + >> + if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RW) { > Is this check still necessary, should they all be RW? Ack > >> + size_t bytes_to_copy; >> + size_t pkt_len; >> + >> + pkt_len = (size_t)le32_to_cpu(pkt->hdr.len); >> + bytes_to_copy = min(user_buf_len, pkt_len); >> + > If bytes_to_copy == 0, we can avoid the next steps (release the lock try > to copy 0 bytes, reacquire the lock) Ack > >> + /* 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; > Here we should reacquire the lock or prevent it from being released out > of cycle. Ack > >> + break; >> + } >> + >> + spin_lock_bh(&vvs->rx_lock); >> + > As mentioned before, I think we could move this part into the core and > here always return the real dimension. Ack > >> + /* If user sets 'MSG_TRUNC' we return real >> length >> + * of message. >> + */ >> + if (flags & MSG_TRUNC) >> + err += pkt_len; >> + else >> + err += bytes_to_copy; >> + >> + user_buf_len -= bytes_to_copy; >> + >> + if (pkt->hdr.flags & VIRTIO_VSOCK_SEQ_EOR) > ^ > We should use le32_to_cpu() to read the flags. > Ack >> + *msg_ready = true; >> + } >> + >> + virtio_transport_dec_rx_pkt(vvs, pkt); >> + list_del(&pkt->list); >> + virtio_transport_free_pkt(pkt); >> + } >> + >> + spin_unlock_bh(&vvs->rx_lock); >> + >> + virtio_transport_send_credit_update(vsk); >> + >> + return err; >> +} >> + >> ssize_t >> virtio_transport_stream_dequeue(struct vsock_sock *vsk, >> struct msghdr *msg, >> @@ -405,6 +466,18 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk, >> } >> EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue); >> >> +ssize_t >> +virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, >> + struct msghdr *msg, >> + int flags, bool *msg_ready) >> +{ >> + if (flags & MSG_PEEK) >> + return -EOPNOTSUPP; >> + >> + return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags, >> msg_ready); >> +} >> +EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue); >> + >> int >> virtio_transport_dgram_dequeue(struct vsock_sock *vsk, >> struct msghdr *msg, >> -- >> 2.25.1 >> >