From patchwork Thu Jun 23 16:53:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 12892962 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 896FCC433EF for ; Thu, 23 Jun 2022 16:57:35 +0000 (UTC) Received: from localhost ([::1]:51772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o4Q98-00028c-Ic for qemu-devel@archiver.kernel.org; Thu, 23 Jun 2022 12:57:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5q-0005r4-5n for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:23637) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5o-0005wG-4e for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656003247; 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: in-reply-to:in-reply-to:references:references; bh=rZS2Qj8OGgQg6pZYnLbW8umeBCQiTi5i+/MP8qAvgLE=; b=SZG31PAhd59Q0sJyID7G2uK1dcpVlJsBOtPBJlwtKpk8eANb42XxsGV/R3MvVqyfcCoD/p tDD0oEFxwEDgul2dJ9pUFiCeFLl1FbDdSfN0dyRjDz1bO4+blBUeBeDfeqqv8JkW/sB8Lh VM386TyTyQW94FpbfA8QGkCIOrfto5c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-402-MnRnrhiPOBWoOzh8yoPuUg-1; Thu, 23 Jun 2022 12:54:04 -0400 X-MC-Unique: MnRnrhiPOBWoOzh8yoPuUg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0A09D3806709; Thu, 23 Jun 2022 16:54:04 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.33.36.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0FF6F2026614; Thu, 23 Jun 2022 16:54:02 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, berrange@redhat.com, huangy81@chinatelecom.cn, quintela@redhat.com, leobras@redhat.com, peterx@redhat.com Cc: jdenemar@redhat.com Subject: [PULL 03/25] QIOChannelSocket: Fix zero-copy send so socket flush works Date: Thu, 23 Jun 2022 17:53:32 +0100 Message-Id: <20220623165354.197792-4-dgilbert@redhat.com> In-Reply-To: <20220623165354.197792-1-dgilbert@redhat.com> References: <20220623165354.197792-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 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_LOW=-0.7, 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" From: Leonardo Bras 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 guarantee 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 Reviewed-by: Daniel P. Berrangé Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela Signed-off-by: Dr. David Alan Gilbert --- io/channel-socket.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/io/channel-socket.c b/io/channel-socket.c index b8c13dba7c..4466bb1cd4 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -611,6 +611,11 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, "Unable to write to socket"); return -1; } + + if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { + sioc->zero_copy_queued++; + } + return ret; } #else /* WIN32 */