Fri, Apr 27, 2018 at 07:06:56PM CEST, sridhar.samudrala@xxxxxxxxx wrote: >v9: >Select NET_FAILOVER automatically when VIRTIO_NET/HYPERV_NET >are enabled. (stephen) > >Tested live migration with virtio-net/AVF(i40evf) configured in >failover mode while running iperf in background. >Build tested netvsc module. > >The main motivation for this patch is to enable cloud service providers >to provide an accelerated datapath to virtio-net enabled VMs in a >transparent manner with no/minimal guest userspace changes. This also >enables hypervisor controlled live migration to be supported with VMs that >have direct attached SR-IOV VF devices. > >Patch 1 introduces a new feature bit VIRTIO_NET_F_STANDBY that can be >used by hypervisor to indicate that virtio_net interface should act as >a standby for another device with the same MAC address. > >Patch 2 introduces a failover module that provides a generic interface for >paravirtual drivers to listen for netdev register/unregister/link change >events from pci ethernet devices with the same MAC and takeover their >datapath. The notifier and event handling code is based on the existing >netvsc implementation. It provides 2 sets of interfaces to paravirtual >drivers to support 2-netdev(netvsc) and 3-netdev(virtio_net) models. > >Patch 3 extends virtio_net to use alternate datapath when available and >registered. When STANDBY feature is enabled, virtio_net driver creates >an additional 'failover' netdev that acts as a master device and controls >2 slave devices. The original virtio_net netdev is registered as >'standby' netdev and a passthru/vf device with the same MAC gets >registered as 'primary' netdev. Both 'standby' and 'primary' netdevs are >associated with the same 'pci' device. The user accesses the network >interface via 'failover' netdev. The 'failover' netdev chooses 'primary' >netdev as default for transmits when it is available with link up and >running. > >Patch 4 refactors netvsc to use the registration/notification framework >supported by failover module. > >As this patch series is initially focusing on usecases where hypervisor >fully controls the VM networking and the guest is not expected to directly >configure any hardware settings, it doesn't expose all the ndo/ethtool ops >that are supported by virtio_net at this time. To support additional usecases, >it should be possible to enable additional ops later by caching the state >in virtio netdev and replaying when the 'primary' netdev gets registered. > >The hypervisor needs to enable only one datapath at any time so that packets >don't get looped back to the VM over the other datapath. When a VF is >plugged, the virtio datapath link state can be marked as down. >At the time of live migration, the hypervisor needs to unplug the VF device >from the guest on the source host and reset the MAC filter of the VF to >initiate failover of datapath to virtio before starting the migration. After >the migration is completed, the destination hypervisor sets the MAC filter >on the VF and plugs it back to the guest to switch over to VF datapath. > >This patch is based on the discussion initiated by Jesse on this thread. >https://marc.info/?l=linux-virtualization&m=151189725224231&w=2 No changes in v9? > >v8: >- Made the failover managment routines more robust by updating the feature > bits/other fields in the failover netdev when slave netdevs are > registered/unregistered. (mst) >- added support for handling vlans. >- Limited the changes in netvsc to only use the notifier/event/lookups > from the failover module. The slave register/unregister/link-change > handlers are only updated to use the getbymac routine to get the > upper netdev. There is no change in their functionality. (stephen) >- renamed structs/function/file names to use net_failover prefix. (mst) > >v7 >- Rename 'bypass/active/backup' terminology with 'failover/primary/standy' > (jiri, mst) >- re-arranged dev_open() and dev_set_mtu() calls in the register routines > so that they don't get called for 2-netdev model. (stephen) >- fixed select_queue() routine to do queue selection based on VF if it is > registered as primary. (stephen) >- minor bugfixes > >v6 RFC: > Simplified virtio_net changes by moving all the ndo_ops of the > bypass_netdev and create/destroy of bypass_netdev to 'bypass' module. > avoided 2 phase registration(driver + instances). > introduced IFF_BYPASS/IFF_BYPASS_SLAVE dev->priv_flags > replaced mutex with a spinlock > >v5 RFC: > Based on Jiri's comments, moved the common functionality to a 'bypass' > module so that the same notifier and event handlers to handle child > register/unregister/link change events can be shared between virtio_net > and netvsc. > Improved error handling based on Siwei's comments. >v4: >- Based on the review comments on the v3 version of the RFC patch and > Jakub's suggestion for the naming issue with 3 netdev solution, > proposed 3 netdev in-driver bonding solution for virtio-net. >v3 RFC: >- Introduced 3 netdev model and pointed out a couple of issues with > that model and proposed 2 netdev model to avoid these issues. >- Removed broadcast/multicast optimization and only use virtio as > backup path when VF is unplugged. >v2 RFC: >- Changed VIRTIO_NET_F_MASTER to VIRTIO_NET_F_BACKUP (mst) >- made a small change to the virtio-net xmit path to only use VF datapath > for unicasts. Broadcasts/multicasts use virtio datapath. This avoids > east-west broadcasts to go over the PCI link. >- added suppport for the feature bit in qemu > >Sridhar Samudrala (4): > virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit > net: Introduce generic failover module > virtio_net: Extend virtio to use VF datapath when available > netvsc: refactor notifier/event handling code to use the failover > framework > > drivers/net/Kconfig | 1 + > drivers/net/hyperv/Kconfig | 1 + > drivers/net/hyperv/hyperv_net.h | 2 + > drivers/net/hyperv/netvsc_drv.c | 134 ++---- > drivers/net/virtio_net.c | 37 +- > include/linux/netdevice.h | 16 + > include/net/net_failover.h | 62 +++ > include/uapi/linux/virtio_net.h | 3 + > net/Kconfig | 10 + > net/core/Makefile | 1 + > net/core/net_failover.c | 892 ++++++++++++++++++++++++++++++++++++++++ > 11 files changed, 1046 insertions(+), 113 deletions(-) > create mode 100644 include/net/net_failover.h > create mode 100644 net/core/net_failover.c > >-- >2.14.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
