On Fri, Mar 2, 2018 at 8:37 AM, Samudrala, Sridhar <sridhar.samudr...@intel.com> wrote: > > > On 3/2/2018 8:20 AM, Jiri Pirko wrote: > > Fri, Mar 02, 2018 at 04:26:25PM CET, alexander.du...@gmail.com wrote: > > On Fri, Mar 2, 2018 at 12:36 AM, Jiri Pirko <j...@resnulli.us> wrote: > > Thu, Mar 01, 2018 at 09:08:43PM CET, sridhar.samudr...@intel.com wrote: > > This patch enables virtio_net to switch over to a VF datapath when a VF > netdev is present with the same MAC address. It allows live migration > of a VM with a direct attached VF without the need to setup a bond/team > between a VF and virtio net device in the guest. > > 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. 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. > > When BACKUP feature is enabled, an additional netdev(bypass netdev) is > created that acts as a master device and tracks the state of the 2 lower > netdevs. The original virtio_net netdev is marked as 'backup' netdev and a > passthru device with the same MAC is registered as 'active' netdev. > > This patch is based on the discussion initiated by Jesse on this thread. > https://marc.info/?l=linux-virtualization&m=151189725224231&w=2 > > Signed-off-by: Sridhar Samudrala <sridhar.samudr...@intel.com> > Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com> > Reviewed-by: Jesse Brandeburg <jesse.brandeb...@intel.com> > --- > drivers/net/virtio_net.c | 683 > ++++++++++++++++++++++++++++++++++++++++++++++- > > As I wrote to the discussion of the other version of this patchset, > I strongly believe you need to have a common part in net/core/ that will > be shared by both virtio_net and netvsc. There there should be explicit > limits for this in-driver bonding solution, like max 1 vf slave, etc. > > Yeah, this code essentially calls out the "shareable" code with a > comment at the start and end of the section what defines the > virtio_bypass functionality. It would just be a matter of mostly > cutting and pasting to put it into a separate driver module. > > Please put it there and unite the use of it with netvsc. > > Based on Stephen's responses, it is not clear if netvsc would be OK to move > to > the 3 netdev solution at this time. When another paravirtual driver would > like > to use this solution, we can do refactoring at that time. > > The design limits things to a 1:1 relationship since we just have the > child and backup pointers, but I don't think I am seeing exception > handling to prevent us from overwriting the child pointers so there > may be a leak there. > > > We only allow one active netdev registered as a child. There is a check to > make sure that if an active netdev is registered, another one with same MAC > is not allowed. I don't think there is a leak. > > vbi = netdev_priv(dev); > backup = (child_netdev->dev.parent == dev->dev.parent); > if (backup ? rtnl_dereference(vbi->backup_netdev) : > rtnl_dereference(vbi->active_netdev)) { > netdev_info(dev, > "%s attempting to join bypass dev when %s > already present\n", > child_netdev->name, backup ? "backup" : > "active"); > return NOTIFY_DONE; > } > > /* Avoid non pci devices as active netdev */ > if (!backup && (!child_netdev->dev.parent || > !dev_is_pci(child_netdev->dev.parent))) > return NOTIFY_DONE; > > Thanks > Sridhar
I overlooked that part. Thanks. - Alex --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
