MFC 309240,309242,309244,309245,309670

309240
hyperv/vmbus: Add result polling support for xact API.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8633

309242
hyperv/vmbus: Add result polling support for message Hypercall API.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8634

309244
hyperv/vmbus: Add exec cancel support for message Hypercall API.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8635

309245
hyperv/vmbus: Use poll/cancel APIs to wait for the CHOPEN response.

Since hypervisor does not respond CHOPEN to a revoked channel.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8636

309670
hyperv/vmbus: Use pause if possible.

This makes booting on Hyper-V w/ small # of vCPUs work properly.

Reported by: Hongxiong Xian <v-hoxian microsoft com>, Hongjiang Zhang <honzhan microsoft com>
Sponsored by: Microsoft

MFC 309030,309039,309080,309081,309083

309030
hyperv/vmbus: Set a mark on the revoked channel.

This will be used to fix device detach DEVMETHOD for revoked primary
channel.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8522

309039
hyperv/vmbus: Merge free/active locks.

These functions are only used by management stuffs, so there are
no needs to introduce extra complexity.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8524

309080
hyperv/vmbus: Implement orphan support for transaction API

It will be used to fix the primary channel revocation support.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8525

309081
hyperv/vmbus: Fix the primary channel revoking on vmbus side.

Drivers can now use vmbus_chan_{is_revoked,set_orphan,unset_orphan}() and
vmbus_xact_ctx_orphan() to fix their attach/detach DEVMETHODs for revoked
primary channels.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8545

309083
hyperv/vmbus: Fix the multi-channel revoking on vmbus side.

- Reference count the sub-channel when channel offer message is
processed, so that immediate rescind message on the same channel
will not race sub-channel open on driver side.
- Drop the above reference when sub-channel is closed, this closely
mimics the hypervisor's reaction when primary channel is closed
on the VM side. No drivers use sub-channel after primary channel
is closed.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8546

MFC 308906

hyperv/vmbus: Support transction result busy-wait.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8488

MFC 303945,303947-303949,303989,303992,303998,304001,304002,304109,304111

303945
hyperv/vmbus: Add macro to get channel packet data length.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7455

303947
hyperv/vmbus: Add APIs for various types of transactions.

Reviewed by: Jun Su <junsu microsoft com>
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7456

303948
hyperv/hn: Switch to vmbus xact APIs for NVS initialization

Reviewed by: Jun Su <junsu microsoft com>
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7457

303949
hyperv/vmbus: Use xact APIs to implement post message Hypercall APIs

Avoid code duplication.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7458

303989
hyperv/hn: Simplify NDIS configuration.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7466

303992
hyperv/hn: Simplify NDIS initialization.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7467

303998
hyperv/hn: Switch to vmbus xact APIs for NVS RXBUF connection.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7469

304001
hyperv/hn: Switch to vmbus xact APIs for NVS chimney buffer connection.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7470

304002
hyperv/hn: Simplify RXBUF disconnection.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7472

304109
hyperv/hn: Simplify chimney sending buffer disconnection.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7479

304111
hyperv/hn: Switch to vmbus xact APIs for sub-channel alloc request.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7480