xen: xenstore changes to support PVH

For PVH guests the xenstore parameters are fetched from the start_info
struct, just like on PV.

Sponsored by: Citrix Systems R&D
Approved by: gibbs

xen/xenstore/xenstore.c:
 - Fetch xenstore event channel port from start_info.
xen: init gnttab from xenpv

Currently the grant table is initialized from xenstore, but a better
place to do this would be xenpv, so move grant table initialization
there.

Sponsored by: Citrix Systems R&D
Approved by: gibbs

x86/xen/xenpv.c:
 - Add gnttab initialization.

xen/xenstore/xenstore.c:
 - Remove gnttab initialization.
xen: unify gnttab initialization for PVHVM and PVH

Switch the initialization of gnttab to use an unused physical memory
range for both PVHVM and PVH.

In the past PVHVM was using the xenpci BAR, but there's no reason to
do that, and in fact FreeBSD was probably doing it because it was the
way it was done in Windows, were drivers cannot probably request for
unused physical memory ranges, but it was never enforced in the
hypervisor.

Sponsored by: Citrix Systems R&D
Approved by: gibbs

xen/gnttab.c:
 - Allocate contiguous physical memory for grant table frames for both
   PVHVM and PVH.
 - Since gnttab is not a device, use the xenpv device in order to
   request for this allocation.

dev/xen/xenpci/xenpcivar.h:
dev/xen/xenpci/xenpci.c:
 - Remove the now unused xenpci_alloc_space and xenpci_alloc_space_int
   functions.

xen/gnttab.h:
 - Change the prototype of gnttab_init and gnttab_resume, that now
   takes a device_t parameter.

dev/xen/control/control.c:
x86/xen/xenpv.c:
 - Changes to accomodate the new prototype of gnttab_init and
   gnttab_resume.
isa: allow ISA bus to attach to xenpv bus

This is needed because syscons depends on ISA.

Sponsored by: Citrix Systems R&D
Approved by: gibbs

x86/isa/isa.c:
 - Allow the ISA bus to attach to xenpv.
xen: add missing files

Commit missing files that actually belong to previous commits.

Sponsored by: Citrix Systems R&D
Approved by: gibbs
Add support for VERIFY(10/12/16) and COMPARE AND WRITE SCSI commands.

Make data_submit backends method support not only read and write requests,
but also two new ones: verify and compare.  Verify just checks readability
of the data in specified location without transferring them outside.
Compare reads the specified data and compares them to received data,
returning error if they are different.

VERIFY(10/12/16) commands request either verify or compare from backend,
depending on BYTCHK CDB field.  COMPARE AND WRITE command executed in two
stages: first it requests compare, and then, if succeesed, requests write.
Atomicity of operation is guarantied by CTL request ordering code.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
Fix destruction of character devices by passing correct pointer to
kernel in IOCTL request.

Submitted by:	Andrey Zholos <aaz@q-fu.com>
Update license to strptime(3) implementation.

Our strptime(3) implementation was the base for the illumos
implementation and after contacting the author, Kevin Rudy
stated the code is under a 2-Clause BSD License [1]

After reviewing our local changes to the file in question,
the FreeBSD Foundation has agreed that their contributions
to this file are not required to carry clause 3 or 4 so
the file can be relicensed as in Illumos [2].

References:

[1] https://www.illumos.org/issues/357
[2] Illumos Revision:		13222:02526851ba75

Approved:	core (jhb)
Approved:	FreeBSD Foundation (emaste)
MFC after:	4 days
Tidy up the early parts of vm_map_insert(), in particular, simplify one
of the assertions and eliminate a comment that has grown stale.

Reviewed by:	kib
MFC after:	1 week
Add LUN-associated name to VPD, to make Hyper-V Failover Cluster happy.

Sponsored by:	The FreeBSD Foundation
- Modify vm_page_unwire() and vm_page_enqueue() to directly accept
  the queue where to enqueue pages that are going to be unwired.
- Add stronger checks to the enqueue/dequeue for the pagequeues when
  adding and removing pages to them.

Of course, for unmanaged pages the queue parameter of vm_page_unwire() will
be ignored, just as the active parameter today.
This makes adding new pagequeues quicker.

This change effectively modifies the KPI.  __FreeBSD_version will be,
however, bumped just when the full cache of free pages will be
evicted.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc
Tested by:	pho
Add comment explaining a potential problem with just added LUN ID.

Reminded by:	mav@
Sponsored by:	The FreeBSD Foundation
Document r267536, Xen PVH DomU support for amd64.

Submitted by:	royger
Sponsored by:	The FreeBSD Foundation
Add &citrix; and &citrix.rd; macros.

Sponsored by:	The FreeBSD Foundation
Bring an overly enthusiastic KASSERT inline with the Intel SDM.

Reviewed by:	neel
Support for multiple disks and tap devices.

This allows you to give a bhyve instance multiple network devices
and disk devices easily by specifying additional "-d " and "-t "
options.

Reviewed by: neel
Sponsored by: Norse
Add MLINKS for macros decribed in queue.3 manpage.
Revert r266925 as it can lead to instant panic at fexecve():

To allow to run the interpreter itself add a new ELF branding type.

Pointed out by:	kib, mjg
In msdosfs_setattr(), add a check for result of the utimes(2)
permissions test, forgotten in r164033.

Refactor the permission checks for utimes(2) into vnode helper
function vn_utimes_perm(9), and simplify its code comparing with the
UFS origin, by writing the call to VOP_ACCESSX only once.  Use the
helper for UFS(5), tmpfs(5), devfs(5) and msdosfs(5).

Reported by:	bde
Reviewed by:	bde, trasz
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

illumos/illumos-dist@5d7b4d438c4a51eccc95e77a83a437b4d48380eb