xfs_file_write_zero_eof is the only caller of xfs_zero_range that does
not take XFS_MMAPLOCK_EXCL (aka the invalidate lock).  Currently that
is actually the right thing, as an error in the iomap zeroing code will
also take the invalidate_lock to clean up, but to fix that deadlock we
need a consistent locking pattern first.

The only extra thing that XFS_MMAPLOCK_EXCL will lock out are read
pagefaults, which isn't really needed here, but also not actively
harmful.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Split a helper from xfs_file_write_checks that just deal with the
post-EOF zeroing to keep the code readable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

XFS (which currently is the only user of iomap_write_delalloc_release)
already holds invalidate_lock for most zeroing operations.  To be able
to avoid a deadlock it needs to stop taking the lock, but doing so
in iomap would leak XFS locking details into iomap.

To avoid this require the caller to hold invalidate_lock when calling
iomap_write_delalloc_release instead of taking it there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Currently iomap_file_buffered_write_punch_delalloc can be called from
XFS either with the invalidate lock held or not.  To fix this while
keeping the locking in the file system and not the iomap library
code we'll need to life the locking up into the file system.

To prepare for that, open code iomap_file_buffered_write_punch_delalloc
in the only caller, and instead export iomap_write_delalloc_release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Split out a pice of logic from iomap_file_buffered_write_punch_delalloc
that is useful for all iomap_end implementations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

The variable declaration in this function predates the merge of the
nrext64 (aka 64-bit extent counters) feature, which means that the
variable declaration type is insufficient to avoid an integer overflow.
Fix that by redeclaring the variable to be xfs_extnum_t.

Coverity-id: 1630958
Fixes: 8f71bede ("xfs: repair inode fork block mapping data structures")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Fix a typo in comments.
Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

fallocate unshare mode explicitly breaks extent sharing. When a
command completes, it checks the data fork for any remaining shared
extents to determine whether the reflink inode flag and COW fork
preallocation can be removed. This logic doesn't consider in-core
pagecache and I/O state, however, which means we can unsafely remove
COW fork blocks that are still needed under certain conditions.

For example, consider the following command sequence:

xfs_io -fc "pwrite 0 1k" -c "reflink <file> 0 256k 1k" \
	-c "pwrite 0 32k" -c "funshare 0 1k" <file>

This allocates a data block at offset 0, shares it, and then
overwrites it with a larger buffered write. The overwrite triggers
COW fork preallocation, 32 blocks by default, which maps the entire
32k write to delalloc in the COW fork. All but the shared block at
offset 0 remains hole mapped in the data fork. The unshare command
redirties and flushes the folio at offset 0, removing the only
shared extent from the inode. Since the inode no longer maps shared
extents, unshare purges the COW fork before the remaining 28k may
have written back.

This leaves dirty pagecache backed by holes, which writeback quietly
skips, thus leaving clean, non-zeroed pagecache over holes in the
file. To verify, fiemap shows holes in the first 32k of the file and
reads return different data across a remount:

$ xfs_io -c "fiemap -v" <file>
<file>:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   ...
   1: [8..511]:        hole               504
   ...
$ xfs_io -c "pread -v 4k 8" <file>
00001000:  cd cd cd cd cd cd cd cd  ........
$ umount <mnt>; mount <dev> <mnt>
$ xfs_io -c "pread -v 4k 8" <file>
00001000:  00 00 00 00 00 00 00 00  ........

To avoid this problem, make unshare follow the same rules used for
background cowblock scanning and never purge the COW fork for inodes
with dirty pagecache or in-flight I/O.

Fixes: 46afb062 ("xfs: only flush the unshared range in xfs_reflink_unshare")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

The background blockgc scanner runs on a 5m interval by default and
trims preallocation (post-eof and cow fork) from inodes that are
otherwise idle. Idle effectively means that iolock can be acquired
without blocking and that the inode has no dirty pagecache or I/O in
flight.

This simple mechanism and heuristic has worked fairly well for
post-eof speculative preallocations. Support for reflink and COW
fork preallocations came sometime later and plugged into the same
mechanism, with similar heuristics. Some recent testing has shown
that COW fork preallocation may be notably more sensitive to blockgc
processing than post-eof preallocation, however.

For example, consider an 8GB reflinked file with a COW extent size
hint of 1MB. A worst case fully randomized overwrite of this file
results in ~8k extents of an average size of ~1MB. If the same
workload is interrupted a couple times for blockgc processing
(assuming the file goes idle), the resulting extent count explodes
to over 100k extents with an average size <100kB. This is
significantly worse than ideal and essentially defeats the COW
extent size hint mechanism.

While this particular test is instrumented, it reflects a fairly
reasonable pattern in practice where random I/Os might spread out
over a large period of time with varying periods of (in)activity.
For example, consider a cloned disk image file for a VM or container
with long uptime and variable and bursty usage. A background blockgc
scan that races and processes the image file when it happens to be
clean and idle can have a significant effect on the future
fragmentation level of the file, even when still in use.

To help combat this, update the heuristic to skip cowblocks inodes
that are currently opened for write access during non-sync blockgc
scans. This allows COW fork preallocations to persist for as long as
possible unless otherwise needed for functional purposes (i.e. a
sync scan), the file is idle and closed, or the inode is being
evicted from cache. While here, update the comments to help
distinguish performance oriented heuristics from the logic that
exists to maintain functional correctness.
Suggested-by: Darrick Wong <djwong@kernel.org>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Currently the debug-only xfs_bmap_exact_minlen_extent_alloc allocation
variant fails to drop into the lowmode last resort allocator, and
thus can sometimes fail allocations for which the caller has a
transaction block reservation.

Fix this by using xfs_bmap_btalloc_low_space to do the actual allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

xfs_bmap_exact_minlen_extent_alloc duplicates the args setup in
xfs_bmap_btalloc.  Switch to call it from xfs_bmap_btalloc after
doing the basic setup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Exact minlen allocations only exist as an error injection tool for debug
builds.  Currently this is implemented using ifdefs, which means the code
isn't even compiled for non-XFS_DEBUG builds.  Enhance the compile test
coverage by always building the code and use the compilers' dead code
elimination to remove it from the generated binary instead.

The only downside is that the alloc_minlen_only field is unconditionally
added to struct xfs_alloc_args now, but by moving it around and packing
it tightly this doesn't actually increase the size of the structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Userdata and metadata allocations end up in the same allocation helpers.
Remove the separate xfs_bmap_alloc_userdata function to make this more
clear.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Just like xfs_attr3_leaf_split, xfs_attr_node_try_addname can return
-ENOSPC both for an actual failure to allocate a disk block, but also
to signal the caller to convert the format of the attr fork.  Use magic
1 to ask for the conversion here as well.

Note that unlike the similar issue in xfs_attr3_leaf_split, this one was
only found by code review.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

xfs_attr3_leaf_split propagates the need for an extra btree split as
-ENOSPC to it's only caller, but the same return value can also be
returned from xfs_da_grow_inode when it fails to find free space.

Distinguish the two cases by returning 1 for the extra split case instead
of overloading -ENOSPC.

This can be triggered relatively easily with the pending realtime group
support and a file system with a lot of small zones that use metadata
space on the main device.  In this case every about 5-10th run of
xfs/538 runs into the following assert:

	ASSERT(oldblk->magic == XFS_ATTR_LEAF_MAGIC);

in xfs_attr3_leaf_split caused by an allocation failure.  Note that
the allocation failure is caused by another bug that will be fixed
subsequently, but this commit at least sorts out the error handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

xfs_attr3_leaf_add only has two potential return values, indicating if the
entry could be added or not.  Replace the errno return with a bool so that
ENOSPC from it can't easily be confused with a real ENOSPC.

Remove the return value from the xfs_attr3_leaf_add_work helper entirely,
as it always return 0.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

xfs_attr_leaf_try_add is only called by xfs_attr_leaf_addname, and
merging the two will simplify a following error handling fix.

To facilitate this move the remote block state save/restore helpers up in
the file so that they don't need forward declarations now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Use !try_cmpxchg instead of cmpxchg (*ptr, old, new) != old in
xlog_cil_insert_pcp_aggregate().  x86 CMPXCHG instruction returns
success in ZF flag, so this change saves a compare after cmpxchg.

Also, try_cmpxchg implicitly assigns old *ptr value to "old" when
cmpxchg fails. There is no need to re-read the value in the loop.

Note that the value from *ptr should be read using READ_ONCE to
prevent the compiler from merging, refetching or reordering the read.

No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Replace a comma between expression statements by a semicolon.
Signed-off-by: Yan Zhen <yanzhen@vivo.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

The definition of xfs_attr_use_log_assist() has been removed since
commit d9c61ccb ("xfs: move xfs_attr_use_log_assist out of xfs_log.c").
So, Remove the empty declartion in header files.
Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

I nominate Carlos Maiolino to take over linux-xfs tree maintainer role for
upstream kernel's XFS code. He has enough experience in Linux kernel and he's
been maintaining xfsprogs and xfsdump trees for a few years now, so he has
sufficient experience with xfs workflow to take over this role.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Acked-by: Carlos Maiolino <cem@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Merge tag 'kbuild-fixes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Move non-boot built-in DTBs to the .rodata section

 - Fix Kconfig bugs

 - Fix maint scripts in the linux-image Debian package

 - Import some list macros to scripts/include/

* tag 'kbuild-fixes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: deb-pkg: Remove blank first line from maint scripts
  kbuild: fix a typo dt_binding_schema -> dt_binding_schemas
  scripts: import more list macros
  kconfig: qconf: fix buffer overflow in debug links
  kconfig: qconf: move conf_read() before drawing tree pain
  kconfig: clear expr::val_is_valid when allocated
  kconfig: fix infinite loop in sym_calc_choice()
  kbuild: move non-boot built-in DTBs to .rodata section

Merge tag 'platform-drivers-x86-v6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Hans de Goede:

 - Intel PMC fix for suspend/resume issues on some Sky and Kaby Lake
   laptops

 - Intel Diamond Rapids hw-id additions

 - Documentation and MAINTAINERS fixes

 - Some other small fixes

* tag 'platform-drivers-x86-v6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors
  platform/x86: wmi: Update WMI driver API documentation
  platform/x86: dell-ddv: Fix typo in documentation
  platform/x86: dell-sysman: add support for alienware products
  platform/x86/intel: power-domains: Add Diamond Rapids support
  platform/x86: ISST: Add Diamond Rapids to support list
  platform/x86:intel/pmc: Disable ACPI PM Timer disabling on Sky and Kaby Lake
  platform/x86: dell-laptop: Do not fail when encountering unsupported batteries
  MAINTAINERS: Update Intel In Field Scan(IFS) entry
  platform/x86: ISST: Fix the KASAN report slab-out-of-bounds bug

Pull kvm fixes from Paolo Bonzini:
 "ARM64:

   - Fix pKVM error path on init, making sure we do not change critical
     system registers as we're about to fail

   - Make sure that the host's vector length is at capped by a value
     common to all CPUs

   - Fix kvm_has_feat*() handling of "negative" features, as the current
     code is pretty broken

   - Promote Joey to the status of official reviewer, while James steps
     down -- hopefully only temporarly

  x86:

   - Fix compilation with KVM_INTEL=KVM_AMD=n

   - Fix disabling KVM_X86_QUIRK_SLOT_ZAP_ALL when shadow MMU is in use

  Selftests:

   - Fix compilation on non-x86 architectures"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86/reboot: emergency callbacks are now registered by common KVM code
  KVM: x86: leave kvm.ko out of the build if no vendor module is requested
  KVM: x86/mmu: fix KVM_X86_QUIRK_SLOT_ZAP_ALL for shadow MMU
  KVM: arm64: Fix kvm_has_feat*() handling of negative features
  KVM: selftests: Fix build on architectures other than x86_64
  KVM: arm64: Another reviewer reshuffle
  KVM: arm64: Constrain the host to the maximum shared SVE VL with pKVM
  KVM: arm64: Fix __pkvm_init_vcpu cptr_el2 error path

Pull powerpc fix from Michael Ellerman:

 - Allow r30 to be used in vDSO code generation of getrandom

Thanks to Jason A. Donenfeld

* tag 'powerpc-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/vdso: allow r30 in vDSO code generation of getrandom

The blank line causes execve() to fail:

  # strace ./postinst
  execve("./postinst", ...) = -1 ENOEXEC (Exec format error)
  strace: exec: Exec format error
  +++ exited with 1 +++

However running the scripts via shell does work (at least with bash)
because the shell attempts to execute the file as a shell script when
execve() fails.

Fixes: b611daae ("kbuild: deb-pkg: split image and debug objects staging out into functions")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

If we follow "make help" to "make dt_binding_schema", we will see
below error:

$ make dt_binding_schema
make[1]: *** No rule to make target 'dt_binding_schema'.  Stop.
make: *** [Makefile:224: __sub-make] Error 2

It should be a typo. So this will fix it.

Fixes: 604a57ba ("dt-bindings: kbuild: Add separate target/dependency for processed-schema.json")
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Import list_is_first, list_is_last, list_replace, and list_replace_init.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

x86_android_tablet_remove() frees the pdevs[] array, so it should not
be used after calling x86_android_tablet_remove().

When platform_device_register() fails, store the pdevs[x] PTR_ERR() value
into the local ret variable before calling x86_android_tablet_remove()
to avoid using pdevs[] after it has been freed.

Fixes: 5eba0141 ("platform/x86: x86-android-tablets: Add support for instantiating platform-devs")
Fixes: e2200d3f ("platform/x86: x86-android-tablets: Add gpio_keys support to x86_android_tablet_init()")
Cc: stable@vger.kernel.org
Reported-by: Aleksandr Burakov <a.burakov@rosalinux.ru>
Closes: https://lore.kernel.org/platform-driver-x86/20240917120458.7300-1-a.burakov@rosalinux.ru/Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241005130545.64136-1-hdegoede@redhat.com

The WMI driver core now passes the WMI event data to legacy notify
handlers, so WMI devices sharing notification IDs are now being
handled properly.

Fixes: e04e2b76 ("platform/x86: wmi: Pass event data directly to legacy notify handlers")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241005213825.701887-1-W_Armin@gmx.deSigned-off-by: Hans de Goede <hdegoede@redhat.com>

Fix typo in word 'diagnostics' in documentation.
Signed-off-by: Anaswara T Rajan <anaswaratrajan@gmail.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241005070056.16326-1-anaswaratrajan@gmail.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

Alienware supports firmware-attributes and has its own OEM string.
Signed-off-by: Crag Wang <crag_wang@dell.com>
Link: https://lore.kernel.org/r/20241004152826.93992-1-crag_wang@dell.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Add Diamond Rapids (INTEL_PANTHERCOVE_X) to tpmi_cpu_ids to support
domaid id mappings.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20241003215554.3013807-3-srinivas.pandruvada@linux.intel.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

Add Diamond Rapids (INTEL_PANTHERCOVE_X) to SST support list by adding
to isst_cpu_ids.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20241003215554.3013807-2-srinivas.pandruvada@linux.intel.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

There have been multiple reports that the ACPI PM Timer disabling is
causing Sky and Kaby Lake systems to hang on all suspend (s2idle, s3,
hibernate) methods.

Remove the acpi_pm_tmr_ctl_offset and acpi_pm_tmr_disable_bit settings from
spt_reg_map to disable the ACPI PM Timer disabling on Sky and Kaby Lake to
fix the hang on suspend.

Fixes: e86c8186 ("platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/linux-pm/18784f62-91ff-4d88-9621-6c88eb0af2b5@molgen.mpg.de/Reported-by: Todd Brandt <todd.e.brandt@intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219346
Cc: Marek Maslanka <mmaslanka@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Todd Brandt <todd.e.brandt@intel.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> # Dell XPS 13 9360/0596KF
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20241003202614.17181-2-hdegoede@redhat.com

If the battery hook encounters a unsupported battery, it will
return an error. This in turn will cause the battery driver to
automatically unregister the battery hook.

On machines with multiple batteries however, this will prevent
the battery hook from handling the primary battery, since it will
always get unregistered upon encountering one of the unsupported
batteries.

Fix this by simply ignoring unsupported batteries.
Reviewed-by: Pali Rohár <pali@kernel.org>
Fixes: ab58016c ("platform/x86:dell-laptop: Add knobs to change battery charge settings")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241001212835.341788-4-W_Armin@gmx.deReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Ashok is no longer with Intel and his e-mail address will start bouncing
soon.  Update his email address to the new one he provided to ensure
correct contact details in the MAINTAINERS file.
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Link: https://lore.kernel.org/r/20241001170808.203970-1-jithu.joseph@intel.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

Merge tag 'kvmarm-fixes-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.12, take #1

- Fix pKVM error path on init, making sure we do not change critical
  system registers as we're about to fail

- Make sure that the host's vector length is at capped by a value
  common to all CPUs

- Fix kvm_has_feat*() handling of "negative" features, as the current
  code is pretty broken

- Promote Joey to the status of official reviewer, while James steps
  down -- hopefully only temporarly

Guard them with CONFIG_KVM_X86_COMMON rather than the two vendor modules.
In practice this has no functional change, because CONFIG_KVM_X86_COMMON
is set if and only if at least one vendor-specific module is being built.
However, it is cleaner to specify CONFIG_KVM_X86_COMMON for functions that
are used in kvm.ko.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 590b09b1 ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Fixes: 6d55a942 ("x86/reboot: Unconditionally define cpu_emergency_virt_cb typedef")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>