• Sridhar Samudrala's avatar
    virtio_net: Extend virtio to use VF datapath when available · ba5e4426
    Sridhar Samudrala authored
    This patch enables virtio_net to switch over to a VF datapath when STANDBY
    feature is enabled and 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.
    
    It uses the API that is exported by the net_failover driver to create and
    and destroy a master failover netdev. When STANDBY feature is enabled, an
    additional netdev(failover 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 'standby' netdev and a passthru device with the same MAC is
    registered as 'primary' netdev.
    
    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=2Signed-off-by: Sridhar Samudrala's avatarSridhar Samudrala <sridhar.samudrala@intel.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    ba5e4426
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