Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Improve error message when failing to open a backing file

When bhyve cannot open a backing file, it now says explicitly which file
could not be opened

Note that the change has only be maed in block_if.c and not in
pci_virtio_block.c as the error will always be catched by the first

PR: 202321 (different patch)
Reviewed by: grehan
MFC after: 3 day
Sponsored by: Gandi.net
Differential Revision: https://reviews.freebsd.org/D6576

Cleanup unused-but-set-variable spotted by gcc-4.9.

Reviewed by: neel
Approved by: rodrigc (mentor)
Differential Revision: https://reviews.freebsd.org/D5042

Allow configuration of the sector size advertised to the guest.

The default behavior is to infer the logical and physical sector sizes from
the block device backend. However older versions of Windows only work with
specific logical/physical combinations:
- Vista and Windows 7: 512/512
- Windows 7 SP1: 512/512 or 512/4096

For this reason allow the sector size to be specified using the following
block device option: sectorsize=logical[/physical]

Reported by: Leon Dang (ldang@nahannisys.com)
Reviewed by: grehan
MFC after: 2 weeks

Workaround bhyve virtual disks operation on top of GEOM providers.

GEOM does not support scatter/gather lists in its I/Os. Such requests
are cut in pieces by physio(), that may be problematic, if those pieces
are not multiple of provider's sector size. If such case is detected,
move the data through temporary sequential buffer.

MFC after: 2 weeks

Pre-allocate one extra request per processing thread.

Processing threads call callbacks before freeing requests. As result,
new requests may arrive before old ones are freed.

MFC after: 2 weeks

Close potential race on blockif_close().

Reported by: vangyzen
MFC after: 2 weeks

Rewrite virtio block device driver to work asynchronously and use the block
I/O interface.

Asynchronous operation, based on r280026 change, allows to not block virtual
CPU during I/O processing, that on slow/busy storage can take seconds.
Use of recently improved block I/O interface allows to process multiple
requests same time, that improves random I/O performance on wide storages.

Benchmarks of virtual disk, backed by ZVOL on RAID10 pool of 4 HDDs, show
~3.5 times random read performance improvements, while no degradation on
linear I/O. Guest CPU usage during test dropped from 100% to almost zero.

MFC after: 2 weeks

Block delete capability for read-only devices.

Submitted by: neel
MFC after: 2 weeks

Give block I/O interface multiple (8) execution threads.

On parallel random I/O this allows better utilize wide storage pools.
To not confuse prefetcher on linear I/O, consecutive requests are executed
sequentially, following the same logic as was earlier implemented in CTL.

Benchmarks of virtual AHCI disk, backed by ZVOL on RAID10 pool of 4 HDDs,
show ~3.5 times random read performance improvements, while no degradation
on linear I/O.

MFC after: 2 weeks

Add DSM TRIM command support for virtual AHCI disks.

It works only for virtual disks backed by ZVOLs and raw devices supporting
BIO_DELETE. Virtual disks backed by files won't report this capability.

MFC after: 2 weeks
Relnotes: yes

Implement cache flush for ahci-hd and for virtio-blk over device.

MFC after: 2 weeks

Report logical/physical sector sizes for virtual SATA disk.

MFC after: 2 weeks

To allow a request to be submitted from within the callback routine of
a completing one increase the total by 1 but don't advertise it.

Reviewed by: grehan

Improve the ability to cancel an in-flight request by using an
interrupt, via SIGCONT, to force the read or write system call to
return prematurely.

Reviewed by: grehan

Support stopping and restarting the AHCI command list via toggling
PxCMD.ST from '1' to '0' and back. This allows the driver a chance to
recover if for instance a timeout occurred due to activity on the
host.

Reviewed by: grehan

Initialize 'bc_rdonly' to the right value.

Note that independent of this change a readonly disk file would still be
opened O_RDONLY and protected from writes by the guest.

Reviewed by: grehan

Add a call to synthesize a C/H/S value for block emulations
that require it (ahci). The algorithm used is from the VHD
specification.

Use calloc() in favor of malloc + memset.

Reviewed by: neel

Increase the block-layer backend maximum number of requests to match
the AHCI command queue depth. This allows a slew of commands issued
by a Linux guest to be absorbed without error.

Approved by: grehan (co-mentor)

Add the VM name to the process name with setproctitle().
Remove the VM name from some of the thread-naming calls
since it is now in the proc title.
Slightly modify the thread-naming for the net and block
threads.

This improves readability when using top/ps with the -a
and -H options on a system with a large number of bhyve VMs.

Requested by: Michael Dexter
Reviewed by: neel
MFC after: 4 weeks

Block-layer backend interface for bhyve block-io device emulations.

Approved by: re@ (blanket)