Those are superseded by the ones in sys/contrib/xen and no longer
used.

Sponsored by: Citrix Systems R&D

Should have never been there in the first place.

This is a verbatim copy of the public headers from Xen 4.14.1.

No functional change intended.

Sponsored by: Citrix Systems R&D

The PVHv2 entry point is fairly similar to the multiboot1 one. The
kernel is started in protected mode with paging disabled. More
information about the exact BSP state can be found in the pvh.markdown
document on the Xen tree.

This entry point is going to be joined with the native entry point at
hammer_time, and in order to do so the BSP needs to be bootstrapped
into long mode with the same set of page tables as used on bare metal.

Sponsored by:	Citrix Systems R&D

This is a license change only commit, which can be found upstream in the Xen
tree as 937324f032f4f77866e80e39de0d697fa5131df1.

Sponsored by: Citrix Systems R&D

(one manual change to fix grammar)

Confirmed With: db
Approved by: secteam (not really, but this is a comment typo fix)

Pull the latest headers for Xen which allow us to add support for ARM and
use new features in FreeBSD.

This is a verbatim copy of the xen/include/public so every headers which
don't exits anymore in the Xen repositories have been dropped.

Note the interface version hasn't been bumped, it will be done in a
follow-up. Although, it requires fix in the code to get it compiled:

 - sys/xen/xen_intr.h: evtchn_port_t is already defined in the headers so
   drop it.

 - {amd64,i386}/include/intr_machdep.h: NR_EVENT_CHANNELS now depends on
   xen/interface/event_channel.h, so include it.

 - {amd64,i386}/{amd64,i386}/support.S: It's not neccessary to include
   machine/intr_machdep.h. This is also fixing build compilation with the
   new headers.

 - dev/xen/blkfront/blkfront.c: The typedef for blkif_request_segmenthas
   been dropped. So directly use struct blkif_request_segment

Finally, modify xen/interface/xen-compat.h to throw a preprocessing error if
__XEN_INTERFACE_VERSION__ is not set. This is allow us to catch any file
where xen/xen-os.h is not correctly included.

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3805
Sponsored by:		Citrix Systems R&D

the blkfront driver to perform I/Os of up to 2 MB, subject to support from
the blkback to which it is connected and the initiation of such large I/Os
by the rest of the kernel.  In practice, the I/O size is increased from 40 kB
to 128 kB.

The changes to xen/interface/io/blkif.h consist merely of merging updates
from the upstream Xen repository.

In dev/xen/blkfront/block.h we add some convenience macros and structure
fields used for indirect-page I/Os: The device records its negotiated limit
on the number of indirect pages used, while each I/O command structure gains
permanently allocated page(s) for indirect page references and the Xen grant
references for those pages.

In dev/xen/blkfront/blkfront.c we now check in xbd_queue_cb whether a request
is small enough to handle without an indirection page, and either follow the
previous behaviour or use new code for issuing an indirect segment I/O.  In
xbd_connect we read the size of indirect segment I/Os supported by the backend
and select the maximum size we will use; then allocate the pages and Xen grant
references for each I/O command structure.  In xbd_free those grants and pages
are released.

A new loader tunable, hw.xbd.xbd_enable_indirect, can be set to 0 in order to
disable this functionality; it works by pretending that the backend does not
support this feature.  Some backends exhibit a loss of performance with large
I/Os, so users may wish to test with and without this functionality enabled.

Reviewed by:	royger
MFC after:	3 days
Relnotes:	yes