MFC: 312687, 312688

MFC: 312687, 312688

Approved by:	sephe (mentor)

r312687
    ifnet: introduce event handlers for ifup/ifdown events

    Hyper-V's NIC SR-IOV implementation needs a Hyper-V synthetic NIC and
    a VF NIC to work together, mainly to support seamless live migration.

    When the VF device becomes UP (or DOWN), the synthetic NIC driver needs
    to switch the data path from the synthetic NIC to the VF (or the opposite).

    So the synthetic NIC driver needs to know when a VF device is becoming
    UP or DOWN and hence the patch is made.

    Reviewed by:	sephe
    Approved by:	sephe (mentor)
    Sponsored by:	Microsoft
    Differential Revision:	https://reviews.freebsd.org/D8963

r312688
    hyperv/hn: add the support for VF drivers (SR-IOV)

    Hyper-V's NIC SR-IOV implementation needs a Hyper-V synthetic NIC and
    a VF NIC to work together (both NICs have the same MAC address), mainly to
    support seamless live migration.

    When the VF device becomes UP (or DOWN), the synthetic NIC driver needs
    to switch the data path from the synthetic NIC to the VF (or the opposite).

    Note: multicast/broadcast packets are still received through the synthetic
    NIC and we need to inject the packets through the VF interface (if the VF is
    UP), even if the synthetic NIC is DOWN (so we need to force the rxfilter
    to be NDIS_PACKET_TYPE_PROMISCUOUS, when the VF is UP).

    Reviewed by:	sephe
    Approved by:	sephe (mentor)
    Sponsored by:	Microsoft
    Differential Revision:	https://reviews.freebsd.org/D8964