Hi! CRIU currently do not support checkpoint/restore of OVS configurations, but there was several requests for it. For example, https://github.com/lxc/lxc/issues/2909
The main problem is ifindexes of newly created interfaces. We realy need to preserve them after restore. Current openvswitch API does not allow to specify ifindex. Most of the time we can just create an interface via generic netlink requests and plug it into ovs but datapaths (generally any OVS_VPORT_TYPE_INTERNAL) can only be created via openvswitch requests which do not support selecting ifindex. This patch allows to do so. For new datapaths I decided to use dp_infindex in header as infindex because it control ifindex for other requests too. For internal vports I reused OVS_VPORT_ATTR_IFINDEX. The only concern I have is that previously dp_ifindex was not used for OVS_DP_VMD_NEW requests and some software may not set it to zero. However we have been running this patch at Virtuozzo for 2 years and have not encountered this problem. Not sure if it is worth to add new ovs_datapath_attr instead. As a broader solution, another generic approach is possible: modify __dev_change_net_namespace() to allow changing ifindexes within the same netns. Yet we will still need to ignore NETIF_F_NETNS_LOCAL and I am not sure that all its users are ready for ifindex change. This will be indeed better for CRIU so we won't need to change every SDN module to be able to checkpoint/restore it. And probably avoid some bloat. What do you think of this? Andrey Zhadchenko (1): openvswitch: allow specifying ifindex of new interfaces include/uapi/linux/openvswitch.h | 4 ++++ net/openvswitch/datapath.c | 16 ++++++++++++++-- net/openvswitch/vport-internal_dev.c | 1 + net/openvswitch/vport.h | 2 ++ 4 files changed, 21 insertions(+), 2 deletions(-) -- 2.31.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
