src/sys/dev/virtio/block, branch release/9.3.0

MFC r260582, r260583:

2014-05-04T00:57:38Z

- Add unmapped IO support to virtio_blk(4) - Add unmapped IO support to virtio_scsi(4)

MFC VirtIO r252702,r252703,r252704,r252706,r252707,r252708,r252709

2013-07-10T04:51:07Z

This brings in several bug fixes and better conformance with various aspects of the spec that have changed. r252702: Convert VirtIO to use ithreads instead of taskqueues r252703: Block driver bug fixes and spec changes r252704: Balloon driver improvements r252706: Minor network driver improvements r252707: Minor misc VirtIO changes r252708: PCI driver bug fixes and cleanup r252709: Fix SCSI driver lock not owned panic

MFC r247829

2013-03-08T02:38:19Z

Only set the barrier flag if the feature was negotiated Approved by: grehan (mentor)

MFC r238072,r238360,r240430,r241469,r241470,r241495,r244136,r244200

2013-02-09T06:11:45Z

Sync VirtIO with HEAD. - r238072: Do not include in the local headers. - r238360: Various VirtIO improvements - r240430: No need to leak these into the includer's namespace. - r241469: virtqueue: Fix non-indirect virtqueues - r241470: Add Virtio SCSI driver - r241495: Fix build with PAE enabled - r244136: Remove duplicated lines - r244200: Start taskqueues threads after attach cannot fail Approved by: grehan (mentor)

MFC r227652, r228301, r234270, r234349

2012-08-21T00:03:04Z

Sync Bryan Venteicher's virtio base, PCI front-end, and net/block/balloon drivers from HEAD.