From patchwork Wed Jun 8 18:18:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Leonardo Bras X-Patchwork-Id: 12874474 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 15B5AC433EF for ; Wed, 8 Jun 2022 18:20:59 +0000 (UTC) Received: from localhost ([::1]:50518 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nz0Ib-0001pp-Q4 for qemu-devel@archiver.kernel.org; Wed, 08 Jun 2022 14:20:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55978) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nz0Gl-0000Ia-QD for qemu-devel@nongnu.org; Wed, 08 Jun 2022 14:19:05 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:30026) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nz0Gj-00054H-0B for qemu-devel@nongnu.org; Wed, 08 Jun 2022 14:19:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654712339; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ykVQD5k8eD9v6FvsSP1QkaBPJ4u6IdVy7bvsBWVCQv4=; b=XlktQWQfony8XrLY9HITspJ1RO77pnnkTfp00xjwVHeszRu3P5Q8NQ4asg0hfqOMGufuLA +Qsh+PVV0K715229po900SIb/zCWpSw7smVT/sOmMtR+MEYr7REPMpftJU9QnYFyH5+qPV yhrrw140Fe/vnH5tNmwS3fT9iRxiRjw= Received: from mail-ot1-f72.google.com (mail-ot1-f72.google.com [209.85.210.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-486-X4meat9IOgObOUYrfFetqw-1; Wed, 08 Jun 2022 14:18:56 -0400 X-MC-Unique: X4meat9IOgObOUYrfFetqw-1 Received: by mail-ot1-f72.google.com with SMTP id n18-20020a9d7112000000b0060bdd3bad6fso6083225otj.12 for ; Wed, 08 Jun 2022 11:18:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ykVQD5k8eD9v6FvsSP1QkaBPJ4u6IdVy7bvsBWVCQv4=; b=uHQ6uyqv301u6KUbj2CdhJG5zpvxhSuRR8OZ5e9YaLmVAdne5YK5UxKboNKwQILOnf IxeZcjknKPqRPU4j4XFJdpVD4qhGtK2+1KNlah2QRAa1CLNehV24e21ot8HiamGUW8f6 hZ5f5CBmD9ykeTeovDaUIU1O5iQaKTisvt+HSKx2SWCeE3wolHGESw/2itwGh4LKTZX/ Nfo/mWKpbW96x/Wid3U0F1mJXiv+skNcvbXMzvqsSQykeh/6vV7HKMetweIzGTtWlP4U CzoVC2rUWLGyb4E/yw1m2zO4Gf7lvdZM4kPedyxdOjDS2HD3b1vtCwHeWQ1hx2O/6i5p jh1w== X-Gm-Message-State: AOAM5307eqyx9DlMp5lPmwtl07PymvcuvVK48QtkBn4IaPyBFrpCPKfd Xw698mEtKmktRuMRGb5JTLKuPgaioWVXgSM2ydB+8wUI3uzfI+geY2QzA0C+h3nlYCu+xoeyBe4 j99t2Z2TTriZLkzw= X-Received: by 2002:a05:6808:1453:b0:32b:93a7:effa with SMTP id x19-20020a056808145300b0032b93a7effamr3089253oiv.27.1654712335502; Wed, 08 Jun 2022 11:18:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz5NizU7z2eWOXVDUP+aacB5Y2qokRBiq5MuJDz9npImL3n+E1LGzyocUZ27K07Oqs0krRQoQ== X-Received: by 2002:a05:6808:1453:b0:32b:93a7:effa with SMTP id x19-20020a056808145300b0032b93a7effamr3089242oiv.27.1654712335284; Wed, 08 Jun 2022 11:18:55 -0700 (PDT) Received: from localhost.localdomain ([2804:431:c7f1:d1b1:8b15:218b:6b0e:5260]) by smtp.gmail.com with ESMTPSA id s42-20020a05683043aa00b0060613c844adsm10847656otv.10.2022.06.08.11.18.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jun 2022 11:18:54 -0700 (PDT) From: Leonardo Bras To: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= Cc: Leonardo Bras , qemu-devel@nongnu.org, Peter Xu , =?utf-8?b?5b6Q6Zev?= Subject: [PATCH v1 1/1] QIOChannelSocket: Fix zero-copy send so socket flush works Date: Wed, 8 Jun 2022 15:18:09 -0300 Message-Id: <20220608181808.79364-1-leobras@redhat.com> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 Received-SPF: pass client-ip=170.10.133.124; envelope-from=leobras@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Somewhere between v6 and v7 the of the zero-copy-send patchset a crucial part of the flushing mechanism got missing: incrementing zero_copy_queued. Without that, the flushing interface becomes a no-op, and there is no garantee the buffer is really sent. This can go as bad as causing a corruption in RAM during migration. Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX") Reported-by: 徐闯 Signed-off-by: Leonardo Bras --- io/channel-socket.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/io/channel-socket.c b/io/channel-socket.c index dc9c165de1..ca4cae930f 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -554,6 +554,7 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, size_t fdsize = sizeof(int) * nfds; struct cmsghdr *cmsg; int sflags = 0; + bool zero_copy_enabled = false; memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)); @@ -581,6 +582,7 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, #ifdef QEMU_MSG_ZEROCOPY if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { sflags = MSG_ZEROCOPY; + zero_copy_enabled = true; } #endif @@ -592,21 +594,24 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, return QIO_CHANNEL_ERR_BLOCK; case EINTR: goto retry; -#ifdef QEMU_MSG_ZEROCOPY case ENOBUFS: - if (sflags & MSG_ZEROCOPY) { + if (zero_copy_enabled) { error_setg_errno(errp, errno, "Process can't lock enough memory for using MSG_ZEROCOPY"); return -1; } break; -#endif } error_setg_errno(errp, errno, "Unable to write to socket"); return -1; } + + if (zero_copy_enabled) { + sioc->zero_copy_queued++; + } + return ret; } #else /* WIN32 */