x86/xen: implement early init hook

Unify the HVM and PVH early setup, byt making both rely on the hypervisor
initialization hook part of identify_hypervisor().

The current initialization takes care of the hypercall page, the sahred info
page and does any fixup necessary to metadata video console information if
FreeBSD is booted as the initial domain (so the video console is handed from
Xen into FreeBSD).

Note this has the nice side effect of also allowing to use the Xen console on
HVM guests, which allows to get rid of the QEMU emulated uart and still get
a nice text console.

Sponsored by: Cloud Software Group
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D43764

x86/xen: do video console fixup as part of early initialization

When FreeBSD is running as dom0 the video console metadata provided by the
bootloader might not be accurate, as Xen has very likely taken over the console
and possibly changed the mode.

Adjust the video console information in the kernel metadata as part of early
Xen initialization.

Sponsored by: Cloud Software Group
Reviewed by: imp
Differential revision: https://reviews.freebsd.org/D43934

x86/xen: move shared page setup to early init handler

As done with the hypercall page, move the setup fo the shared info page into
the newly introduced helper, which the aim of having a single helper and call
site used by both HVM and PV in order to setup the basic Xen environment.

Sponsored by: Cloud Software Group
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D43933

x86/xen: introduce a Xen early init function

Start by moving the hyeprcall setup to such function.

The aim is to have a function that does all the required Xen early
initialization for both HVM and PVH, instead of having it scattered across
different paths.

Sponsored by: Cloud Software Group
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D43932

x86/xen: remove parameter from fixup_console()

And instead fetch the metadata inside of the function.

This is done in preparation for changing the call site of fixup_console(),
which will no longer have the kernel metedata pointer in context.

No functional change intended.

Sponsored by: Cloud Software Group
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D43931

xen: remove xen_domain_type enum/variable

The vm_guest variable readily covers all uses of xen_domain_type, so
merge them together. Since support for PV domains has been removed
hard-core xen_pv_domain() to return false.

Reviewed by: royger

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Revert "Revert "tslog: Annotate some early boot functions""

Now that <sys/tslog.h> is wrapped in #ifdef _KERNEL, it's safe to have
tslog annotations in files which might be built from userland (i.e. in
subr_boot.c, which is built as part of the boot loader).

This reverts commit 59588a546f55523d6fd37ab42eb08b719311d7d6.

Revert "tslog: Annotate some early boot functions"

The change to subr_boot.c broke the libsa build because the TSLOG
macros have their own definitions for the boot loader -- I didn't
realize that the loader code used subr_boot.c.

I'm currently testing a fix and I'll revert this revert once I'm
satisfied that everything works, but I don't want to leave the
tree broken for too long.

This reverts commit 469cfa3c30ee7a5ddeb597d0a8c3e7cac909b27a.

tslog: Annotate some early boot functions

Booting an amd64 kernel on Firecracker with 1 CPU and 128 MB of RAM,
hammer_time takes roughly 2740 us:
* 55 us in xen_pvh_parse_preload_data
* 20 us in boot_parse_cmdline_delim
* 20 us in boot_env_to_howto
* 15 us in identify_hypervisor
* 1320 us in link_elf_reloc
* 1310 us in relocate_file1 handling ef->rela
* 25 us in init_param1
* 30 us in dpcpu_init
* 355 us in initializecpu
* 255 us in initializecpu calling load_cr4
* 425 us in getmemsize
* 280 us in pmap_bootstrap
* 205 us in create_pagetables
* 10 us in init_param2
* 25 us in pci_early_quirks
* 60 us in cninit
* 90 us in kdb_init
* 105 us in msgbufinit
* 20 us in fpuinit
* 205 us elsewhere in hammer_time

Some of these are unavoidable (e.g. identify_hypervisor uses CPUID and
load_cr4 loads the CR4 register, both of which trap to the hypervisor)
but others may deserve attention.

Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D40325

spdx: The BSD-2-Clause-NetBSD identifier is obsolete, drop -NetBSD

The SPDX folks have obsoleted the BSD-2-Clause-NetBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

xen: take struct size into account for video information

The xenpf_dom0_console_t structure can grow as more data is added, and
hence we need to check that the fields we accesses have been filled by
Xen. The only extra field FreeBSD currently uses is the top 32 bits
for the frame buffer physical address.

Note that this field is present in all the versions that make the
information available from the platform hypercall interface, so the
check here is mostly cosmetic, and to remember us that newly added
fields require checking the size of the returned data.

Fixes: 6f80738b228c ('xen: fetch dom0 video console information from Xen')
Sponsored by: Citrix Systems R&D

xen: fetch dom0 video console information from Xen

It's possible for Xen to switch the video mode set by the boot loader,
so that the information passed in the kernel metadata is no longer
valid. Fetch the video mode used by Xen using an hypercall and update
the medatada for the kernel to use the correct video mode.

Sponsored by: Citrix Systems R&D

PVH: Set bootmethod to PVH

Now that we can PVH boot on a non-Xen hypervisor, we shouldn't set
machdep.bootmethod to "XEN". Instead, set it to "PVH"; there are
other ways to discern the hypervisor.

Reviewed by: royger
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D36191

PVH: support whitespace cmdline splitting

For historical reasons, Xen kernel command lines have options
separated by commas. Every other FreeBSD platform uses whitespace;
this is also necessary in PVH in order to support the Firecracker
VMM. Allow options to be separated by any combination of commas
and whitespace.

Reviewed by: imp
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D36190

x86: Distinguish Xen from non-Xen PVH boots

The PVH boot protocol, introduced by Xen, is now used by some non-Xen
platforms (e.g. the Firecracker VM) as well. In order to accommodate
these, we use CPUID to detect Xen and only perform Xen-specific setup
when running on that platform.

The "isxen" function duplicates some work done by identcpu.c later in
the boot process; but we need it here since this is the very first C
code which runs when PVH booting (even before hammer_time).

In many places the existing code had
xc_printf(...);
HYPERVISOR_shutdown(SHUTDOWN_crash);
making use of Xen functionality to print a message and shut down; in
the places where this idiom can be reached in the non-xen case, we
replace it idiom with a CRASH(...) macro which calls those in the Xen
case and halts in the non-Xen case.

Reviewed by: royger
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D35801

x86: Add support for PVH version 1 memmap

Version 0 of PVH booting uses a Xen hypercall to retrieve the system
memory map; in version 1 the memory map can be provided via the
start_info structure.

Using the memory map from the version 1 start_info structure allows
FreeBSD to use PVH booting on systems other than Xen, e.g. on the
Firecracker VM.

Reviewed by: royger
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D35800

x86/xen: stop assuming kernel memory loading order in PVH

Do not assume that start_info will always be loaded at the highest
memory address, and instead check the position of all the loaded
elements in order to find the last loaded one, and thus a likely safe
place to use as early boot allocation memory space.

Reported by: markj, cperciva
Sponsored by: Citrix Systems R&D
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D35628

xen: switch to use headers in contrib

These headers originate with the Xen project and shouldn't be mixed with
the main portion of the FreeBSD kernel. Notably they shouldn't be the
target of clean-up commits.

Switch to use the headers in sys/contrib/xen.

Reviewed by: royger

xen: plug some of set-but-not-used vars

Sponsored by: Rubicon Communications, LLC ("Netgate")

xen: Fix warning by adding KERNBASE to modlist_paddr before casting

Clang 13 produces the following warning for hammer_time_xen():

sys/x86/xen/pv.c:183:19: error: the pointer incremented by -2147483648 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements) [-Werror,-Warray-bounds]
(vm_paddr_t)start_info->modlist_paddr + KERNBASE;
^ ~~~~~~~~
sys/xen/interface/arch-x86/hvm/start_info.h:131:5: note: array 'modlist_paddr' declared here
uint64_t modlist_paddr; /* Physical address of an array of */
^

This is because the expression first casts start_info->modlist_paddr to
struct hvm_modlist_entry * (via vmpaddr_t), and *then* adds KERNBASE,
which is then interpreted as KERNBASE * sizeof(struct
hvm_modlist_entry).

Instead, parenthesize the addition to get the intended result, and cast
it to struct hvm_modlist_entry * afterwards. Also remove the cast to
vmpaddr_t since it is not necessary.

Reviewed by: royger
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D31711

x86/xen: further PVHv1 removal cleanup

The AP startup extern variable declarations are not longer needed,
since PVHv2 uses the native AP startup path using the lapic. Remove
the declaration and make the variables static to mp_machdep.c

Sponsored by: Citrix Systems R&D

xen: Remove leftover bits missed in commit ac3ede5371

Fixes: ac3ede5371 ("x86/xen: remove PVHv1 code")
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D30316

x86/xen: remove PVHv1 code

PVHv1 was officially removed from Xen in 4.9, so just axe the related
code from FreeBSD.

Note FreeBSD supports PVHv2, which is the replacement for PVHv1.

Sponsored by: Citrix Systems R&D
Reviewed by: kib, Elliott Mitchell
Differential Revision: https://reviews.freebsd.org/D30228

xen: remove support for PVHv1 bootpath

PVHv1 is a legacy interface supported only by Xen versions 4.4 through
4.9.

Reviewed by: royger

xen/boot: allow specifying boot method when booted from Xen

Allow setting the bootmethod variable from the Xen PVH entry point, in
order to be able to correctly set the underlying firmware mode when
booted as a dom0.

Move the bootmethod variable to be defined in x86/cpu_machdep.c
instead so it can be shared by both i386 and amd64.

Sponsored by: Citrix Systems R&D
Reviewed by: kib
Differential revision: https://reviews.freebsd.org/D28619

stand/multiboot: adjust the protocol between loader and kernel

There's a currently ad-hoc protocol to hand off the FreeBSD kernel
payload between the loader and the kernel itself when Xen is in the
middle of the picture. Such protocol wasn't very resilient to changes
to the loader itself, because it relied on moving metadata around to
package it using a certain layout. This has proven to be fragile, so
replace it with a more robust version.

The new protocol requires using a xen_header structure that will be
used to pass data between the FreeBSD loader and the FreeBSD kernel
when booting in dom0 mode. At the moment the only data conveyed is the
offset of the start of the module metadata relative to the start of the
module itself.

This is a slightly disruptive change since it also requires a change
to the kernel which is contained in this patch. In order to update
with this change the kernel must be updated before updating the
loader, as described in the handbook. Note this is only required when
booting a FreeBSD/Xen dom0. This change doesn't affect the normal
FreeBSD boot protocol.

This fixes booting FreeBSD/Xen in dom0 mode after
3630506b9daec9167a89bc4525638ea45a00769e.

Sponsored by: Citrix Systems R&D
MFC after: 3 days
Reviewed by: tsoome
Differential Revision: https://reviews.freebsd.org/D28411

x86: clean up empty lines in .c and .h files

Provide string functions for use before ifuncs get resolved.

The change is a no-op for architectures which don't ifunc memset,
memcpy nor memmove.

Convert places which need them. Xen bits by royger.

Reviewed by: kib
Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17487

xen: fix initial kenv setup for legacy PVH

When adding support for the new PVH mode the kenv handling was
switched to use a boot time allocated scratch space, however the
legacy PVH early boot code was not modified to allocate such space.

Approved by: re (gjb)
Sponsored by: Citrix Systems R&D

Eliminate kmem_malloc()'s unused arena parameter. (The arena parameter
became unused in FreeBSD 12.x as a side-effect of the NUMA-related
changes.)

Reviewed by: kib, markj
Discussed with: jeff, re@
Differential Revision: https://reviews.freebsd.org/D16825

xen: implement early init helper for PVHv2

In order to setup an initial environment and jump into the generic
hammer_time initialization function. Some of the code is shared with
PVHv1, while other code is PVHv2 specific.

This allows booting FreeBSD as a PVHv2 DomU and Dom0.

Sponsored by: Citrix Systems R&D

xen: remove direct usage of HYPERVISOR_start_info

HYPERVISOR_start_info is only available to PV and PVHv1 guests, HVM
and PVHv2 guests get this data from HVM parameters that are fetched
using a hypercall.

Instead provide a set of helper functions that should be used to fetch
this data. The helper functions have different implementations
depending on whether FreeBSD is running as PVHv1 or HVM/PVHv2 guest
type.

This helps to cleanup generic Xen code by removing quite a lot of
xen_pv_domain and xen_hvm_domain macro usages.

Sponsored by: Citrix Systems R&D

Create helper functions for parsing boot args.

boot_parse_arg to parse a single arg
boot_parse_cmdline to parse a command line string
boot_parse_args to parse all the args in a vector
boot_howto_to_env Convert howto bits to env vars
boot_env_to_howto Return howto mask mased on what's set in the environment.

All these routines return an int that's the bitmask of the args
translated to RB_* flags. As a special case, the 'S' flag sets the
comconsole_speed env var. Any arg that looks like a=b will set the env
key 'a' to value 'b'. If =b is omitted, 'a' is set to '1'. This
should help us reduce the number of redundant copies of these routines
in the tree. It should also give a more uniform experience between
platforms.

Also, invent a new flag RB_PROBE that's set when 'P' is parsed. On
x86 + BIOS, this means 'probe for the keyboard, and if it's not there
set both RB_MULTIPLE and RB_SERIAL (which means show the output on
both video and serial consoles, but make serial primary). Others it
may be some similar concept of probing, but it's loader dependent
what, exactly, it means.

These routines are suitable for /boot/loader and/or the kernel,
though they may not be suitable for the tightly hand-rolled-for-space
environments like boot2.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D16205

xen/pvh: allocate dbg_stack

Or else init_secondary will hit a page fault (or write garbage
somewhere).

Sponsored by: Citrix Systems R&D

xen: fix formatting of xen_init_ops

No functional change

Sponsored by: Citrix Systems R&D

xen: fix smp boot after r328157

mce_stack was left unset leading to early crashes

sys/x86: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Remove misc NULL checks after M_WAITOK allocations.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Make the 'env' directive described in config(5) work on all architectures,
providing compiled-in static environment data that is used instead of any
data passed in from a boot loader.

Previously 'env' worked only on i386 and arm xscale systems, because it
required the MD startup code to examine the global envmode variable and
decide whether to use static_env or an environment obtained from the boot
loader, and set the global kern_envp accordingly. Most startup code wasn't
doing so. Making things even more complex, some mips startup code uses an
alternate scheme that involves calling init_static_kenv() to pass an empty
buffer and its size, then uses a series of kern_setenv() calls to populate
that buffer.

Now all MD startup code calls init_static_kenv(), and that routine provides
a single point where envmode is checked and the decision is made whether to
use the compiled-in static_kenv or the values provided by the MD code.

The routine also continues to serve its original purpose for mips; if a
non-zero buffer size is passed the routine installs the empty buffer ready
to accept kern_setenv() values. Now if the size is zero, the provided buffer
full of existing env data is installed. A NULL pointer can be passed if the
boot loader provides no env data; this allows the static env to be installed
if envmode is set to do so.

Most of the work here is a near-mechanical change to call the init function
instead of directly setting kern_envp. A notable exception is in xen/pv.c;
that code was originally installing a buffer full of preformatted env data
along with its non-zero size (like mips code does), which would have allowed
kern_setenv() calls to wipe out the preformatted data. Now it passes a zero
for the size so that the buffer of data it installs is treated as
non-writeable.

Remove redundant declarations in sys/x86/xen which are now handled in other sys/x86
headers

Differential Revision: https://reviews.freebsd.org/D4685
X-MFC with: r291949
Sponsored by: EMC / Isilon Storage Division

Make kstack_pages a tunable on arm, x86, and powepc. On i386, the
initial thread stack is not adjusted by the tunable, the stack is
allocated too early to get access to the kernel environment. See
TD0_KSTACK_PAGES for the thread0 stack sizing on i386.

The tunable was tested on x86 only. From the visual inspection, it
seems that it might work on arm and powerpc. The arm
USPACE_SVC_STACK_TOP and powerpc USPACE macros seems to be already
incorrect for the threads with non-default kstack size. I only
changed the macros to use variable instead of constant, since I cannot
test.

On arm64, mips and sparc64, some static data structures are sized by
KSTACK_PAGES, so the tunable is disabled.

Sponsored by: The FreeBSD Foundation
MFC after: 2 week

Fix KSTACK_PAGES issue when the default value was changed in KERNCONF

If KSTACK_PAGES was changed to anything alse than the default,
the value from param.h was taken instead in some places and
the value from KENRCONF in some others. This resulted in
inconsistency which caused corruption in SMP envorinment.

Ensure all places where KSTACK_PAGES are used the opt_kstack_pages.h
is included.

The file opt_kstack_pages.h could not be included in param.h
because was breaking the toolchain compilation.

Reviewed by: kib
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3094

loader: fix the size of MODINFOMD_MODULEP

The data in MODINFOMD_MODULEP is packed by the loader as a 4 byte type, but
the amd64 kernel expects a vm_paddr_t, which is of size 8 bytes. Fix this by
saving it as 8 bytes in the loader and retrieving it using the proper type
in the kernel.

Sponsored by: Citrix Systems R&D

loader: implement multiboot support for Xen Dom0

Implement a subset of the multiboot specification in order to boot Xen
and a FreeBSD Dom0 from the FreeBSD bootloader. This multiboot
implementation is tailored to boot Xen and FreeBSD Dom0, and it will
most surely fail to boot any other multiboot compilant kernel.

In order to detect and boot the Xen microkernel, two new file formats
are added to the bootloader, multiboot and multiboot_obj. Multiboot
support must be tested before regular ELF support, since Xen is a
multiboot kernel that also uses ELF. After a multiboot kernel is
detected, all the other loaded kernels/modules are parsed by the
multiboot_obj format.

The layout of the loaded objects in memory is the following; first the
Xen kernel is loaded as a 32bit ELF into memory (Xen will switch to
long mode by itself), after that the FreeBSD kernel is loaded as a RAW
file (Xen will parse and load it using it's internal ELF loader), and
finally the metadata and the modules are loaded using the native
FreeBSD way. After everything is loaded we jump into Xen's entry point
using a small trampoline. The order of the multiboot modules passed to
Xen is the following, the first module is the RAW FreeBSD kernel, and
the second module is the metadata and the FreeBSD modules.

Since Xen will relocate the memory position of the second
multiboot module (the one that contains the metadata and native
FreeBSD modules), we need to stash the original modulep address inside
of the metadata itself in order to recalculate its position once
booted. This also means the metadata must come before the loaded
modules, so after loading the FreeBSD kernel a portion of memory is
reserved in order to place the metadata before booting.

In order to tell the loader to boot Xen and then the FreeBSD kernel the
following has to be added to the /boot/loader.conf file:

xen_cmdline="dom0_mem=1024M dom0_max_vcpus=2 dom0pvh=1 console=com1,vga"
xen_kernel="/boot/xen"

The first argument contains the command line that will be passed to the Xen
kernel, while the second argument is the path to the Xen kernel itself. This
can also be done manually from the loader command line, by for example
typing the following set of commands:

OK unload
OK load /boot/xen dom0_mem=1024M dom0_max_vcpus=2 dom0pvh=1 console=com1,vga
OK load kernel
OK load zfs
OK load if_tap
OK load ...
OK boot

Sponsored by: Citrix Systems R&D
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D517

For the Forth bits:
Submitted by: Julien Grall <julien.grall AT citrix.com>

xen: fix usage of kern_getenv in PVH code

The value returned by kern_getenv should be freed using freeenv.

Reported by: Coverity
CID: 1248852
Sponsored by: Citrix Systems R&D

Follow up to r225617. In order to maximize the re-usability of kernel code
in userland rename in-kernel getenv()/setenv() to kern_setenv()/kern_getenv().
This fixes a namespace collision with libc symbols.

Submitted by: kmacy
Tested by: make universe

msi: add Xen MSI implementation

This patch adds support for MSI interrupts when running on Xen. Apart
from adding the Xen related code needed in order to register MSI
interrupts this patch also makes the msi_init function a hook in
init_ops, so different MSI implementations can have different
initialization functions.

Sponsored by: Citrix Systems R&D

xen/interface/physdev.h:
- Add the MAP_PIRQ_TYPE_MULTI_MSI to map multi-vector MSI to the Xen
public interface.

x86/include/init.h:
- Add a hook for setting custom msi_init methods.

amd64/amd64/machdep.c:
i386/i386/machdep.c:
- Set the default msi_init hook to point to the native MSI
initialization method.

x86/xen/pv.c:
- Set the Xen MSI init hook when running as a Xen guest.

x86/x86/local_apic.c:
- Call the msi_init hook instead of directly calling msi_init.

xen/xen_intr.h:
x86/xen/xen_intr.c:
- Introduce support for registering/releasing MSI interrupts with
Xen.
- The MSI interrupts will use the same PIC as the IO APIC interrupts.

xen/xen_msi.h:
x86/xen/xen_msi.c:
- Introduce a Xen MSI implementation.

x86/xen/xen_nexus.c:
- Overwrite the default MSI hooks in the Xen Nexus to use the Xen MSI
implementation.

x86/xen/xen_pci.c:
- Introduce a Xen specific PCI bus that inherits from the ACPI PCI
bus and overwrites the native MSI methods.
- This is needed because when running under Xen the MSI messages used
to configure MSI interrupts on PCI devices are written by Xen
itself.

dev/acpica/acpi_pci.c:
- Lower the quality of the ACPI PCI bus so the newly introduced Xen
PCI bus can take over when needed.

conf/files.i386:
conf/files.amd64:
- Add the newly created files to the build process.

xen: add proper copyright attribution

Noted by: jmallett

ddb: allow specifying the exact address of the symtab and strtab

When the FreeBSD kernel is loaded from Xen the symtab and strtab are
not loaded the same way as the native boot loader. This patch adds
three new global variables to ddb that can be used to specify the
exact position and size of those tables, so they can be directly used
as parameters to db_add_symbol_table. A new helper is introduced, so callers
that used to set ksym_start and ksym_end can use this helper to set the new
variables.

It also adds support for loading them from the Xen PVH port, that was
previously missing those tables.

Sponsored by: Citrix Systems R&D
Reviewed by: kib

ddb/db_main.c:
- Add three new global variables: ksymtab, kstrtab, ksymtab_size that
can be used to specify the position and size of the symtab and
strtab.
- Use those new variables in db_init in order to call db_add_symbol_table.
- Move the logic in db_init to db_fetch_symtab in order to set ksymtab,
kstrtab, ksymtab_size from ksym_start and ksym_end.

ddb/ddb.h:
- Add prototype for db_fetch_ksymtab.
- Declate the extern variables ksymtab, kstrtab and ksymtab_size.

x86/xen/pv.c:
- Add support for finding the symtab and strtab when booted as a Xen
PVH guest. Since Xen loads the symtab and strtab as NetBSD expects
to find them we have to adapt and use the same method.

amd64/amd64/machdep.c:
arm/arm/machdep.c:
i386/i386/machdep.c:
mips/mips/machdep.c:
pc98/pc98/machdep.c:
powerpc/aim/machdep.c:
powerpc/booke/machdep.c:
sparc64/sparc64/machdep.c:
- Use the newly introduced db_fetch_ksymtab in order to set ksymtab,
kstrtab and ksymtab_size.

Fix build with SMP disabled.

CR: https://phabric.freebsd.org/D407
Reviewed by: royger

xen: add hooks for Xen PV APIC

Create the necessary hooks in order to provide a Xen PV APIC
implementation that can be used on PVH. Most of the lapic ops
shouldn't be called on Xen, since we trap those operations at a higher
layer.

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

x86/xen/hvm.c:
x86/xen/xen_apic.c:
- Move IPI related code to xen_apic.c

x86/xen/xen_apic.c:
- Introduce Xen PV APIC implementation, most of the functions of the
lapic interface should never be called when running as PV(H) guest,
so make sure FreeBSD panics when trying to use one of those.
- Define the Xen APIC implementation in xen_apic_ops.

xen/xen_pv.h:
- Extern declaration of the xen_apic struct.

x86/xen/pv.c:
- Use xen_apic_ops as apic_ops when running as PVH guest.

conf/files.amd64:
conf/files.i386:
- Include the xen_apic.c file in the build of i386/amd64 kernels
using XENHVM.

xen: fix style in pv.c

Fix the lenght of some comments, and also add proper indentation to
xen_init_ops

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

Make this compile with gcc.

Submitted by: royger@

xen: add a hook to perform AP startup

AP startup on PVH follows the PV method, so we need to add a hook in
order to diverge from bare metal.

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

amd64/amd64/machdep.c:
- Add hook for start_all_aps on native (using native_start_all_aps
defined in mp_machdep).

amd64/amd64/mp_machdep.c:
- Make some variables global because they will also be used by the
Xen PVH AP startup code.
- Use the start_all_aps hook to start APs.
- Rename start_all_aps to native_start_all_aps.

amd64/include/smp.h:
- Add declaration for native_start_all_aps.

x86/include/init.h:
- Declare start_all_aps hook in init_ops.

x86/xen/pv.c:
- Pick external declarations from mp_machdep.
- Introduce Xen PV code to start APs on PVH.
- Set start_all_aps init hook to use the Xen PVH implementation.

xen: implement hook to fetch and parse e820 memory map

e820 memory map is fetched using a hypercall under Xen PVH, so add a
hook to init_ops in oder to diverge from bare metal and implement a
Xen variant.

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

x86/include/init.h:
- Add a parse_memmap hook to init_ops, that will be called to fetch
and parse the memory map.

amd64/amd64/machdep.c:
- Decouple the fetch and the parse of the memmap, so the parse
function can be shared with Xen code.
- Move code around in order to implement the parse_memmap hook.

amd64/include/pc/bios.h:
- Declare bios_add_smap_entries (implemented in machdep.c).

x86/xen/pv.c:
- Implement fetching of e820 memmap when running as a PVH guest by
using the XENMEM_memory_map hypercall.

xen: implement an early timer for Xen PVH

When running as a PVH guest, there's no emulated i8254, so we need to
use the Xen PV timer as the early source for DELAY. This change allows
for different implementations of the early DELAY function and
implements a Xen variant for it.

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

dev/xen/timer/timer.c:
dev/xen/timer/timer.h:
- Implement Xen early delay functions using the PV timer and declare
them.

x86/include/init.h:
- Add hooks for early clock source initialization and early delay
functions.

i386/i386/machdep.c:
pc98/pc98/machdep.c:
amd64/amd64/machdep.c:
- Set early delay hooks to use the i8254 on bare metal.
- Use clock_init (that will in turn make use of init_ops) to
initialize the early clock source.

amd64/include/clock.h:
i386/include/clock.h:
- Declare i8254_delay and clock_init.

i386/xen/clock.c:
- Rename DELAY to i8254_delay.

x86/isa/clock.c:
- Introduce clock_init that will take care of initializing the early
clock by making use of the init_ops hooks.
- Move non ISA related delay functions to the newly introduced delay
file.

x86/x86/delay.c:
- Add moved delay related functions.
- Implement generic DELAY function that will use the init_ops hooks.

x86/xen/pv.c:
- Set PVH hooks for the early delay related functions in init_ops.

conf/files.amd64:
conf/files.i386:
conf/files.pc98:
- Add delay.c to the kernel build.

amd64: introduce hook for custom preload metadata parsers

Add hooks to amd64 in order to have diverging implementations, since
on Xen PV the metadata is passed to the kernel in a different form.

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

amd64/amd64/machdep.c:
- Define init_ops for native.
- Put native code inside of native_parse_preload_data hook.
- Call the parse_preload_data in order to fill the metadata info.

x86/include/init.h:
- Declare the init_ops struct.

x86/xen/pv.c:
- Declare xen_init_ops that contains the Xen PV implementation of
init_ops.
- Implement the parse_preload_data for Xen PVH, the info is fetched
from HYPERVISOR_start_info->cmd_line as provided by Xen.

howto_names: unify declaration

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

boot/i386/efi/bootinfo.c:
boot/i386/libi386/bootinfo.c:
boot/ia64/common/bootinfo.c:
boot/powerpc/ofw/metadata.c:
boot/powerpc/ps3/metadata.c:
boot/sparc64/loader/metadata.c:
boot/uboot/common/metadata.c:
boot/userboot/userboot/bootinfo.c:
i386/xen/xen_machdep.c:
- Include sys/boot.h
- Remove custom definition of howto_names.

sys/boot.h:
- Define howto_names.

x86/xen/pv.c:
- Include sys/boot.h

xen: add and enable Xen console for PVH guests

This adds and enables the PV console used on XEN kernels to
GENERIC/XENHVM kernels in order for it to be used on PVH.

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

dev/xen/console/console.c:
- Define console_page.
- Move xc_printf debug function from i386 XEN code to generic console
code.
- Rework xc_printf.
- Use xen_initial_domain instead of open-coded checks for Dom0.
- Gate the attach of the PV console to PV(H) guests.

dev/xen/console/xencons_ring.c:
- Allow the PV Xen console to output earlier by directly signaling
the event channel in start_info if the event channel is not yet
initialized.
- Use HYPERVISOR_start_info instead of xen_start_info.

i386/include/xen/xen-os.h:
- Remove prototype for xc_printf since it's now declared in global
xen-os.h

i386/xen/xen_machdep.c:
- Remove previous version of xc_printf.
- Remove definition of console_page (now it's defined in the console
itself).
- Fix some printf formatting errors.

x86/xen/pv.c:
- Add some early boot debug messages using xc_printf.
- Set console_page based on the value passed in start_info.

xen/xen-os.h:
- Declare console_page and add prototype for xc_printf.

xen: add PV/PVH kernel entry point

Add the PV/PVH entry point and the low level functions for PVH
early initialization.

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

amd64/amd64/genassym.c:
- Add __FreeBSD_version define to assym.s so it can be used for the
Xen notes.

amd64/amd64/locore.S:
- Make bootstack global so it can be used from Xen kernel entry
point.

amd64/amd64/xen-locore.S:
- Add Xen notes to the kernel.
- Add the Xen PV entry point, that is going to call hammer_time_xen.

amd64/include/asmacros.h:
- Add ELFNOTE macros.

i386/xen/xen_machdep.c:
- Define HYPERVISOR_start_info for the XEN i386 PV port, which is
going to be used in some shared code between PV and PVH.

x86/xen/hvm.c:
- Define HYPERVISOR_start_info for the PVH port.

x86/xen/pv.c:
- Introduce hammer_time_xen which is going to perform early setup for
Xen PVH:
- Setup shared Xen variables start_info, shared_info and
xen_store.
- Set guest type.
- Create initial page tables as FreeBSD expects to find them.
- Call into native init function (hammer_time).

xen/xen-os.h:
- Declare HYPERVISOR_start_info.

conf/files.amd64:
- Add amd64/amd64/locore.S and x86/xen/pv.c to the list of files.