From nobody Fri May 3 14:38:41 2024 Delivered-To: importer@patchew.org Received-SPF: temperror (zoho.com: Error in retrieving data from DNS) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=temperror (zoho.com: Error in retrieving data from DNS) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1510846035744198.0989966843813; Thu, 16 Nov 2017 07:27:15 -0800 (PST) Received: from localhost ([::1]:41394 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFM4B-0006cZ-Bw for importer@patchew.org; Thu, 16 Nov 2017 10:26:59 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35544) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFM3K-0006Dt-TF for qemu-devel@nongnu.org; Thu, 16 Nov 2017 10:26:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFM3F-00036m-PQ for qemu-devel@nongnu.org; Thu, 16 Nov 2017 10:26:06 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:65248) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1eFM3F-00030o-I4 for qemu-devel@nongnu.org; Thu, 16 Nov 2017 10:26:01 -0500 X-IronPort-AV: E=Sophos;i="5.44,404,1505779200"; d="scan'208";a="459650547" From: Anthony PERARD To: Date: Thu, 16 Nov 2017 15:14:19 +0000 Message-ID: <20171116151419.694-1-anthony.perard@citrix.com> X-Mailer: git-send-email 2.15.0 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 66.165.176.63 Subject: [Qemu-devel] [PATCH v2 for-2.11] migration, xen: Fix block image lock issue on live migration 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: Kevin Wolf , Stefano Stabellini , Wei Liu , Juan Quintela , Ian Jackson , "Dr. David Alan Gilbert" , Markus Armbruster , Anthony PERARD Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_6 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When doing a live migration of a Xen guest with libxl, the images for block devices are locked by the original QEMU process, and this prevent the QEMU at the destination to take the lock and the migration fail. From QEMU point of view, once the RAM of a domain is migrated, there is two QMP commands, "stop" then "xen-save-devices-state", at which point a new QEMU is spawned at the destination. Release locks in "xen-save-devices-state" so the destination can takes them, if it's a live migration. This patch add the "live" parameter to "xen-save-devices-state" which default to true so older version of libxenlight can work with newer version of QEMU. Signed-off-by: Anthony PERARD Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela --- Changes in V2: - add the live parameter CC: Kevin Wolf also CCing libxl maintainers: CC: Ian Jackson CC: Wei Liu --- migration/savevm.c | 23 ++++++++++++++++++++++- qapi/migration.json | 6 +++++- 2 files changed, 27 insertions(+), 2 deletions(-) diff --git a/migration/savevm.c b/migration/savevm.c index 4a88228614..7bc4e23e65 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2242,13 +2242,20 @@ int save_snapshot(const char *name, Error **errp) return ret; } =20 -void qmp_xen_save_devices_state(const char *filename, Error **errp) +void qmp_xen_save_devices_state(const char *filename, bool has_live, bool = live, + Error **errp) { QEMUFile *f; QIOChannelFile *ioc; int saved_vm_running; int ret; =20 + if (!has_live) { + /* live default to true so old version of Xen tool stack can have a + * successfull live migration */ + live =3D true; + } + saved_vm_running =3D runstate_is_running(); vm_stop(RUN_STATE_SAVE_VM); global_state_store_running(); @@ -2263,6 +2270,20 @@ void qmp_xen_save_devices_state(const char *filename= , Error **errp) qemu_fclose(f); if (ret < 0) { error_setg(errp, QERR_IO_ERROR); + } else { + /* libxl calls the QMP command "stop" before calling + * "xen-save-devices-state" and in case of migration failure, libxl + * would call "cont". + * So call bdrv_inactivate_all (release locks) here to let the oth= er + * side of the migration take controle of the images. + */ + if (live && !saved_vm_running) { + ret =3D bdrv_inactivate_all(); + if (ret) { + error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)", + __func__, ret); + } + } } =20 the_end: diff --git a/qapi/migration.json b/qapi/migration.json index bbc4671ded..03f57c9616 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -1075,6 +1075,9 @@ # data. See xen-save-devices-state.txt for a description of the binary # format. # +# @live: Optional argument to ask QEMU to treat this command as part of a = live +# migration. Default to true. (since 2.11) +# # Returns: Nothing on success # # Since: 1.1 @@ -1086,7 +1089,8 @@ # <- { "return": {} } # ## -{ 'command': 'xen-save-devices-state', 'data': {'filename': 'str'} } +{ 'command': 'xen-save-devices-state', + 'data': {'filename': 'str', '*live':'bool' } } =20 ## # @xen-set-replication: --=20 Anthony PERARD