From patchwork Fri May 19 06:43:27 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 764444 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wTdnW3n0Lz9s3s for ; Fri, 19 May 2017 16:44:15 +1000 (AEST) Received: from localhost ([::1]:56837 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBbe1-0000X1-3L for incoming@patchwork.ozlabs.org; Fri, 19 May 2017 02:44:13 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36716) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBbdc-0000Wg-A8 for qemu-devel@nongnu.org; Fri, 19 May 2017 02:43:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBbdb-00049L-9w for qemu-devel@nongnu.org; Fri, 19 May 2017 02:43:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58096) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBbdb-00049H-0j for qemu-devel@nongnu.org; Fri, 19 May 2017 02:43:47 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DDAB87F4A3 for ; Fri, 19 May 2017 06:43:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com DDAB87F4A3 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=peterx@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com DDAB87F4A3 Received: from pxdev.xzpeter.org.com (ovpn-12-101.pek2.redhat.com [10.72.12.101]) by smtp.corp.redhat.com (Postfix) with ESMTP id C28CE17196; Fri, 19 May 2017 06:43:42 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 19 May 2017 14:43:27 +0800 Message-Id: <1495176212-14446-2-git-send-email-peterx@redhat.com> In-Reply-To: <1495176212-14446-1-git-send-email-peterx@redhat.com> References: <1495176212-14446-1-git-send-email-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 19 May 2017 06:43:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH RFC 1/6] io: only allow return path for socket typed X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Dr . David Alan Gilbert" , peterx@redhat.com, Juan Quintela Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" We don't really have a return path for the other types yet. Let's check this when .get_return_path() is called. For this, we introduce a new feature bit, and set it up only for socket typed IO channels. This will help detect earlier failure for postcopy, e.g., logically speaking postcopy cannot work with "exec:". Before this patch, when we try to migrate with "migrate -d exec:cat>out", we'll hang the system. With this patch, we'll get: (qemu) migrate -d exec:cat>out Unable to open return-path for postcopy CC: Daniel P. Berrange Signed-off-by: Peter Xu --- include/io/channel.h | 1 + io/channel-socket.c | 1 + migration/qemu-file-channel.c | 9 +++++++++ 3 files changed, 11 insertions(+) diff --git a/include/io/channel.h b/include/io/channel.h index db9bb02..7876534 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -45,6 +45,7 @@ enum QIOChannelFeature { QIO_CHANNEL_FEATURE_FD_PASS, QIO_CHANNEL_FEATURE_SHUTDOWN, QIO_CHANNEL_FEATURE_LISTEN, + QIO_CHANNEL_FEATURE_RETURN_PATH, }; diff --git a/io/channel-socket.c b/io/channel-socket.c index 53386b7..ee81b2d 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -56,6 +56,7 @@ qio_channel_socket_new(void) ioc = QIO_CHANNEL(sioc); qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN); + qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH); #ifdef WIN32 ioc->event = CreateEvent(NULL, FALSE, FALSE, NULL); diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c index 45c13f1..3bd7940 100644 --- a/migration/qemu-file-channel.c +++ b/migration/qemu-file-channel.c @@ -23,6 +23,7 @@ */ #include "qemu/osdep.h" +#include "qom/object.h" #include "migration/qemu-file.h" #include "io/channel-socket.h" #include "qemu/iov.h" @@ -139,6 +140,10 @@ static QEMUFile *channel_get_input_return_path(void *opaque) { QIOChannel *ioc = QIO_CHANNEL(opaque); + if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH)) { + return NULL; + } + return qemu_fopen_channel_output(ioc); } @@ -146,6 +151,10 @@ static QEMUFile *channel_get_output_return_path(void *opaque) { QIOChannel *ioc = QIO_CHANNEL(opaque); + if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH)) { + return NULL; + } + return qemu_fopen_channel_input(ioc); }