MFC 295743,295744,295745,295746,295747

MFC 295743,295744,295745,295746,295747

295743
    hyperv/hn: Change global tunable prefix to hw.hn

    And use SYSCTL+CTLFLAG_RDTUN for them.

    Suggested by:       adrian
    Reviewed by:        adrian, Hongjiang Zhang <honzhan microsoft com>
    Approved by:        adrian (mentor)
    MFC after:  1 week
    Sponsored by:       Microsoft OSTC
    Differential Revision:      https://reviews.freebsd.org/D5274

295744
    hyperv/hn: Split RX ring data structure out of softc

    This paves the way for upcoming vRSS stuffs and eases more code cleanup.

    Reviewed by:        adrian
    Approved by:        adrian (mentor)
    MFC after:  1 week
    Sponsored by:       Microsoft OSTC
    Differential Revision:      https://reviews.freebsd.org/D5275

295745
    hyperv/hn: Use taskqueue_enqueue()

    This also eases experiment on the non-fast taskqueue.

    Reviewed by:        adrian, Jun Su <junsu microsoft com>
    Approved by:        adrian (mentor)
    MFC after:  1 week
    Sponsored by:       Microsoft OSTC
    Differential Revision:      https://reviews.freebsd.org/D5276

295746
    hyperv/hn: Use non-fast taskqueue for transmission

    Performance stays same; so no need to use fast taskqueue here.

295747
    hyperv/hn: Split TX ring data structure out of softc

    This paves the way for upcoming vRSS stuffs and eases more code cleanup.

    Reviewed by:        adrian
    Approved by:        adrian (mentor)
    MFC after:  1 week
    Sponsored by:       Microsoft OSTC
    Differential Revision:      https://reviews.freebsd.org/D5283

git-svn-id: svn://svn.freebsd.org/base/stable/10@301861 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f