From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36685) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d4sby-0005Qb-EK for qemu-devel@nongnu.org; Sun, 30 Apr 2017 13:26:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d4sbw-0005wP-Ou for qemu-devel@nongnu.org; Sun, 30 Apr 2017 13:26:18 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36325 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d4sbw-0005vX-IK for qemu-devel@nongnu.org; Sun, 30 Apr 2017 13:26:16 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3UHNpEj075927 for ; Sun, 30 Apr 2017 13:26:15 -0400 Received: from e24smtp04.br.ibm.com (e24smtp04.br.ibm.com [32.104.18.25]) by mx0a-001b2d01.pphosted.com with ESMTP id 2a5ja9bc4u-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 30 Apr 2017 13:26:15 -0400 Received: from localhost by e24smtp04.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 30 Apr 2017 14:26:14 -0300 From: Daniel Henrique Barboza Date: Sun, 30 Apr 2017 14:25:46 -0300 In-Reply-To: <20170430172547.13415-1-danielhb@linux.vnet.ibm.com> References: <20170430172547.13415-1-danielhb@linux.vnet.ibm.com> Message-Id: <20170430172547.13415-5-danielhb@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 4/5] migration: spapr: migrate ccs_list in spapr state List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, david@gibson.dropbear.id.au From: Jianjun Duan ccs_list in spapr state maintains the device tree related information on the rtas side for hotplugged devices. In racing situations between hotplug events and migration operation, a rtas hotplug event could be migrated from the source guest to target guest, or the source guest could have not yet finished fetching the device tree when migration is started, the target will try to finish fetching the device tree. By migrating ccs_list, the target can fetch the device tree properly. In theory there would be other alternatives besides migrating the css_list to fix this. For example, we could add a flag that indicates whether a device is in the middle of the configure_connector during the migration process, in the post_load we can detect if this flag is active and then return an error informing the guest to restart the hotplug process. However, the DRC state can still be modified outside of hotplug. Using: drmgr -c pci -s -r drmgr -c pci -s -a it is possible to return a device to firmware and then later take it back and reconfigure it. This is not a common case but it's not prohibited, and performing a migration between these 2 operations would fail because the default coldplug state on target assumes a configured state in the source*. Migrating ccs_list is one solution that cover this case as well. ccs_list is put in a subsection in the spapr state VMSD to make sure migration across different versions is not broken. * see http://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg01763.html for more information on this discussion. Signed-off-by: Jianjun Duan Signed-off-by: Daniel Henrique Barboza --- hw/ppc/spapr.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 8b9a6cf..cb3f0e8 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -1437,6 +1437,37 @@ static bool version_before_3(void *opaque, int version_id) return version_id < 3; } +static bool spapr_ccs_list_needed(void *opaque) +{ + sPAPRMachineState *spapr = (sPAPRMachineState *)opaque; + return !QTAILQ_EMPTY(&spapr->ccs_list); +} + +static const VMStateDescription vmstate_spapr_ccs = { + .name = "spapr_configure_connector_state", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(drc_index, sPAPRConfigureConnectorState), + VMSTATE_INT32(fdt_offset, sPAPRConfigureConnectorState), + VMSTATE_INT32(fdt_depth, sPAPRConfigureConnectorState), + VMSTATE_END_OF_LIST() + }, +}; + +static const VMStateDescription vmstate_spapr_ccs_list = { + .name = "spapr_ccs_list", + .version_id = 1, + .minimum_version_id = 1, + .needed = spapr_ccs_list_needed, + .fields = (VMStateField[]) { + VMSTATE_QTAILQ_V(ccs_list, sPAPRMachineState, 1, + vmstate_spapr_ccs, sPAPRConfigureConnectorState, + next), + VMSTATE_END_OF_LIST() + }, +}; + static bool spapr_ov5_cas_needed(void *opaque) { sPAPRMachineState *spapr = opaque; @@ -1535,6 +1566,7 @@ static const VMStateDescription vmstate_spapr = { .subsections = (const VMStateDescription*[]) { &vmstate_spapr_ov5_cas, &vmstate_spapr_patb_entry, + &vmstate_spapr_ccs_list, NULL } }; -- 2.9.3