x86/xen: attempt to inflate the memory balloon on PVH

When running as PVH or HVM Linux will use holes in the memory map as scratch
space to map grants, foreign domain pages and possibly miscellaneous other
stuff. However the usage of such memory map holes for Xen purposes can be
problematic. The request of holesby Xen happen quite early in the kernel boot
process (grant table setup already uses scratch map space), and it's possible
that by then not all devices have reclaimed their MMIO space. It's not
unlikely for chunks of Xen scratch map space to end up using PCI bridge MMIO
window memory, which (as expected) causes quite a lot of issues in the system.

At least for PVH dom0 we have the possibility of using regions marked as
UNUSABLE in the e820 memory map. Either if the region is UNUSABLE in the
native memory map, or it has been converted into UNUSABLE in order to hide RAM
regions from dom0, the second stage translation page-tables can populate those
areas without issues.

PV already has this kind of logic, where the balloon driver is inflated at
boot. Re-use the current logic in order to also inflate it when running as
PVH. onvert UNUSABLE regions up to the ratio specified in EXTRA_MEM_RATIO to
RAM, while reserving them using xen_add_extra_mem() (which is also moved so
it's no longer tied to CONFIG_PV).

[jgross: fixed build for CONFIG_PVH without CONFIG_XEN_PVH]

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20240220174341.56131-1-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>

x86: Do not include <asm/bootparam.h> in several files

Remove the include statement for <asm/bootparam.h> from several files
that don't require it and limit the exposure of those definitions within
the Linux kernel code.

[ bp: Massage commit message. ]

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-5-tzimmermann@suse.de

x86/PVH: avoid 32-bit build warning when obtaining VGA console info

In the commit referenced below I failed to pay attention to this code
also being buildable as 32-bit. Adjust the type of "ret" - there's no
real need for it to be wider than 32 bits.

Fixes: 934ef33ee75c ("x86/PVH: obtain VGA console info in Dom0")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

Link: https://lore.kernel.org/r/2d2193ff-670b-0a27-e12d-2c5c4c121c79@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

x86/PVH: obtain VGA console info in Dom0

A new platform-op was added to Xen to allow obtaining the same VGA
console information PV Dom0 is handed. Invoke the new function and have
the output data processed by xen_init_vga().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

Link: https://lore.kernel.org/r/8f315e92-7bda-c124-71cc-478ab9c5e610@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/x86: adjust data placement

Both xen_pvh and xen_start_flags get written just once early during
init. Using the respective annotation then allows the open-coded placing
in .data to go away.

Additionally the former, like the latter, wants exporting, or else
xen_pvh_domain() can't be used from modules.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/8155ed26-5a1d-c06f-42d8-596d26e75849@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/x86: hook up xen_banner() also for PVH

This was effectively lost while dropping PVHv1 code. Move the function
and arrange for it to be called the same way as done in PV mode. Clearly
this then needs re-introducing the XENFEAT_mmu_pt_update_preserve_ad
check that was recently removed, as that's a PV-only feature.

Since the string pointed at by pv_info.name describes the mode, drop
"paravirtualized" from the log message while moving the code.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/de03054d-a20d-2114-bb86-eec28e17b3b8@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/x86: generalize preferred console model from PV to PVH Dom0

Without announcing hvc0 as preferred it won't get used as long as tty0
gets registered earlier. This is particularly problematic with there not
being any screen output for PVH Dom0 when the screen is in graphics
mode, as the necessary information doesn't get conveyed yet from the
hypervisor.

Follow PV's model, but be conservative and do this for Dom0 only for
now.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/582328b6-c86c-37f3-d802-5539b7a86736@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

treewide: Convert macro and uses of __section(foo) to __section("foo")

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xen/pvh: correctly setup the PV EFI interface for dom0

This involves initializing the boot params EFI related fields and the
efi global variable.

Without this fix a PVH dom0 doesn't detect when booted from EFI, and
thus doesn't support accessing any of the EFI related data.

Reported-by: PGNet Dev <pgnet.dev@gmail.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org # 4.19+

xen/pvh: set xen_domain_type to HVM in xen_pvh_init

Or else xen_domain() returns false despite xen_pvh being set.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org # 4.19+

xen/pvh: Move Xen code for getting mem map via hcall out of common file

We need to refactor PVH entry code so that support for other hypervisors
like Qemu/KVM can be added more easily.

The original design for PVH entry in Xen guests relies on being able to
obtain the memory map from the hypervisor using a hypercall. When we
extend the PVH entry ABI to support other hypervisors like Qemu/KVM,
a new mechanism will be added that allows the guest to get the memory
map without needing to use hypercalls.

For Xen guests, the hypercall approach will still be supported. In
preparation for adding support for other hypervisors, we can move the
code that uses hypercalls into the Xen specific file. This will allow us
to compile kernels in the future without CONFIG_XEN that are still capable
of being booted as a Qemu/KVM guest via the PVH entry point.

Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

xen/pvh: Move Xen specific PVH VM initialization out of common file

We need to refactor PVH entry code so that support for other hypervisors
like Qemu/KVM can be added more easily.

This patch moves the small block of code used for initializing Xen PVH
virtual machines into the Xen specific file. This initialization is not
going to be needed for Qemu/KVM guests. Moving it out of the common file
is going to allow us to compile kernels in the future without CONFIG_XEN
that are still capable of being booted as a Qemu/KVM guest via the PVH
entry point.

Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

xen/pvh: Create a new file for Xen specific PVH code

We need to refactor PVH entry code so that support for other hypervisors
like Qemu/KVM can be added more easily.

The first step in that direction is to create a new file that will
eventually hold the Xen specific routines.

Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

x86/xen: Fix boot loader version reported for PVH guests

The boot loader version reported via sysfs is wrong in case of the
kernel being booted via the Xen PVH boot entry. it should be 2.12
(0x020c), but it is reported to be 2.18 (0x0212).

As the current way to set the version is error prone use the more
readable variant (2 << 8) | 12.

Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org> # 4.12
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: corbet@lwn.net
Cc: linux-doc@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181010061456.22238-2-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

xen: don't include <xen/xen.h> from <asm/io.h> and <asm/dma-mapping.h>

Nothing Xen specific in these headers, which get included from a lot
of code in the kernel. So prune the includes and move them to the
Xen-specific files that actually use them instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

xen: share start flags between PV and PVH

Use a global variable to store the start flags for both PV and PVH.
This allows the xen_initial_domain macro to work properly on PVH.

Note that ARM is also switched to use the new variable.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

x86/xen: Add pvh specific rsdp address retrieval function

Add pvh_get_root_pointer() for Xen PVH guests to communicate the
address of the RSDP table given to the kernel via Xen start info.

This makes the kernel boot again in PVH mode after on recent Xen the
RSDP was moved to higher addresses. So up to that change it was pure
luck that the legacy method to locate the RSDP was working when
running as PVH mode.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: lenb@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20180219100906.14265-4-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/virt/xen: Use guest_late_init to detect Xen PVH guest

In case we are booted via the default boot entry by a generic loader
like grub or OVMF it is necessary to distinguish between a HVM guest
with a device model supporting legacy devices and a PVH guest without
device model.

PVH guests will always have x86_platform.legacy.no_vga set and
x86_platform.legacy.rtc cleared, while both won't be true for HVM
guests.

Test for both conditions in the guest_late_init hook and set xen_pvh
to true if they are met.

Move some of the early PVH initializations to the new hook in order
to avoid duplicated code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-6-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xen/pvh: Do not fill kernel's e820 map in init_pvh_bootparams()

e820 map is updated with information from the zeropage (i.e. pvh_bootparams)
by default_machine_specific_memory_setup(). With the way things are done
now, we end up with a duplicated e820 map.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

x86/xen: split off enlighten_pvh.c

Create enlighten_pvh.c by splitting off PVH related code from enlighten.c,
put it under CONFIG_XEN_PVH.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>