Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...

Pull x86 cpu updates from Ingo Molnar:

 - Rework the x86 CPU vendor/family/model code: introduce the 'VFM'
   value that is an 8+8+8 bit concatenation of the vendor/family/model
   value, and add macros that work on VFM values. This simplifies the
   addition of new Intel models & families, and simplifies existing
   enumeration & quirk code.

 - Add support for the AMD 0x80000026 leaf, to better parse topology
   information

 - Optimize the NUMA allocation layout of more per-CPU data structures

 - Improve the workaround for AMD erratum 1386

 - Clear TME from /proc/cpuinfo as well, when disabled by the firmware

 - Improve x86 self-tests

 - Extend the mce_record tracepoint with the ::ppin and ::microcode fields

 - Implement recovery for MCE errors in TDX/SEAM non-root mode

 - Misc cleanups and fixes

* tag 'x86-cpu-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  x86/mm: Switch to new Intel CPU model defines
  x86/tsc_msr: Switch to new Intel CPU model defines
  x86/tsc: Switch to new Intel CPU model defines
  x86/cpu: Switch to new Intel CPU model defines
  x86/resctrl: Switch to new Intel CPU model defines
  x86/microcode/intel: Switch to new Intel CPU model defines
  x86/mce: Switch to new Intel CPU model defines
  x86/cpu: Switch to new Intel CPU model defines
  x86/cpu/intel_epb: Switch to new Intel CPU model defines
  x86/aperfmperf: Switch to new Intel CPU model defines
  x86/apic: Switch to new Intel CPU model defines
  perf/x86/msr: Switch to new Intel CPU model defines
  perf/x86/intel/uncore: Switch to new Intel CPU model defines
  perf/x86/intel/pt: Switch to new Intel CPU model defines
  perf/x86/lbr: Switch to new Intel CPU model defines
  perf/x86/intel/cstate: Switch to new Intel CPU model defines
  x86/bugs: Switch to new Intel CPU model defines
  x86/bugs: Switch to new Intel CPU model defines
  x86/cpu/vfm: Update arch/x86/include/asm/intel-family.h
  x86/cpu/vfm: Add new macros to work with (vendor/family/model) values
  ...

Patch series "mm/mm_init.c: refactor free_area_init_core()".

In function free_area_init_core(), the code calculating
zone->managed_pages and the subtracting dma_reserve from DMA zone looks
very confusing.

From git history, the code calculating zone->managed_pages was for
zone->present_pages originally.  The early rough assignment is for
optimize zone's pcp and water mark setting.  Later, managed_pages was
introduced into zone to represent the number of managed pages by buddy. 
Now, zone->managed_pages is zeroed out and reset in mem_init() when
calling memblock_free_all().  zone's pcp and wmark setting relying on
actual zone->managed_pages are done later than mem_init() invocation.  So
we don't need rush to early calculate and set zone->managed_pages, just
set it as zone->present_pages, will adjust it in mem_init().

And also add a new function calc_nr_kernel_pages() to count up free but
not reserved pages in memblock, then assign it to nr_all_pages and
nr_kernel_pages after memmap pages are allocated.


This patch (of 6):

Variable dma_reserve and its usage was introduced in commit 0e0b864e069c
("[PATCH] Account for memmap and optionally the kernel image as holes"). 
Its original purpose was to accounting for the reserved pages in DMA zone
to make DMA zone's watermarks calculation more accurate on x86.

However, currently there's zone->managed_pages to account for all
available pages for buddy, zone->present_pages to account for all present
physical pages in zone.  What is more important, on x86, calculating and
setting the zone->managed_pages is a temporary move, all zone's
managed_pages will be zeroed out and reset to the actual value according
to how many pages are added to buddy allocator in mem_init().  Before
mem_init(), no buddy alloction is requested.  And zone's pcp and watermark
setting are all done after mem_init().  So, no need to worry about the DMA
zone's setting accuracy during free_area_init().

Hence, remove memblock_find_dma_reserve() to stop calculating and
setting dma_reserve.

Link: https://lkml.kernel.org/r/20240325145646.1044760-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20240325145646.1044760-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

There are few uses of CoCo that don't rely on working cryptography and
hence a working RNG. Unfortunately, the CoCo threat model means that the
VM host cannot be trusted and may actively work against guests to
extract secrets or manipulate computation. Since a malicious host can
modify or observe nearly all inputs to guests, the only remaining source
of entropy for CoCo guests is RDRAND.

If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole
is meant to gracefully continue on gathering entropy from other sources,
but since there aren't other sources on CoCo, this is catastrophic.
This is mostly a concern at boot time when initially seeding the RNG, as
after that the consequences of a broken RDRAND are much more
theoretical.

So, try at boot to seed the RNG using 256 bits of RDRAND output. If this
fails, panic(). This will also trigger if the system is booted without
RDRAND, as RDRAND is essential for a safe CoCo boot.

Add this deliberately to be "just a CoCo x86 driver feature" and not
part of the RNG itself. Many device drivers and platforms have some
desire to contribute something to the RNG, and add_device_randomness()
is specifically meant for this purpose.

Any driver can call it with seed data of any quality, or even garbage
quality, and it can only possibly make the quality of the RNG better or
have no effect, but can never make it worse.

Rather than trying to build something into the core of the RNG, consider
the particular CoCo issue just a CoCo issue, and therefore separate it
all out into driver (well, arch/platform) code.

  [ bp: Massage commit message. ]

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Elena Reshetova <elena.reshetova@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240326160735.73531-1-Jason@zx2c4.com

When split_lock_detect=off (or similar) is specified in
CONFIG_CMDLINE, its effect is lost. The flow is currently this:

	setup_arch():
	  -> early_cpu_init()
	    -> early_identify_cpu()
	      -> sld_setup()
		-> sld_state_setup()
		  -> Looks for split_lock_detect in boot_command_line

	  -> e820__memory_setup()

	  -> Assemble final command line:
	     boot_command_line = builtin_cmdline + boot_cmdline

	  -> parse_early_param()

There were earlier attempts at fixing this in:

  8d48bf8206f7 ("x86/boot: Pull up cmdline preparation and early param parsing")

later reverted in:

  fbe618399854 ("Revert "x86/boot: Pull up cmdline preparation and early param parsing"")

... because parse_early_param() can't be called before
e820__memory_setup().

In this patch, we just move the command line concatenation to the
beginning of early_cpu_init(). This should fix sld_state_setup(), while
not running in the same issues as the earlier attempt.

The order is now:

	setup_arch():
	  -> Assemble final command line:
	     boot_command_line = builtin_cmdline + boot_cmdline

	  -> early_cpu_init()
	    -> early_identify_cpu()
	      -> sld_setup()
		-> sld_state_setup()
		  -> Looks for split_lock_detect in boot_command_line

	  -> e820__memory_setup()

	  -> parse_early_param()

Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org

SEV-SNP requires encrypted memory to be validated before access.
Because the ROM memory range is not part of the e820 table, it is not
pre-validated by the BIOS. Therefore, if a SEV-SNP guest kernel wishes
to access this range, the guest must first validate the range.

The current SEV-SNP code does indeed scan the ROM range during early
boot and thus attempts to validate the ROM range in probe_roms().
However, this behavior is neither sufficient nor necessary for the
following reasons:

* With regards to sufficiency, if EFI_CONFIG_TABLES are not enabled and
  CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK is set, the kernel will
  attempt to access the memory at SMBIOS_ENTRY_POINT_SCAN_START (which
  falls in the ROM range) prior to validation.

  For example, Project Oak Stage 0 provides a minimal guest firmware
  that currently meets these configuration conditions, meaning guests
  booting atop Oak Stage 0 firmware encounter a problematic call chain
  during dmi_setup() -> dmi_scan_machine() that results in a crash
  during boot if SEV-SNP is enabled.

* With regards to necessity, SEV-SNP guests generally read garbage
  (which changes across boots) from the ROM range, meaning these scans
  are unnecessary. The guest reads garbage because the legacy ROM range
  is unencrypted data but is accessed via an encrypted PMD during early
  boot (where the PMD is marked as encrypted due to potentially mapping
  actually-encrypted data in other PMD-contained ranges).

In one exceptional case, EISA probing treats the ROM range as
unencrypted data, which is inconsistent with other probing.

Continuing to allow SEV-SNP guests to use garbage and to inconsistently
classify ROM range encryption status can trigger undesirable behavior.
For instance, if garbage bytes appear to be a valid signature, memory
may be unnecessarily reserved for the ROM range. Future code or other
use cases may result in more problematic (arbitrary) behavior that
should be avoided.

While one solution would be to overhaul the early PMD mapping to always
treat the ROM region of the PMD as unencrypted, SEV-SNP guests do not
currently rely on data from the ROM region during early boot (and even
if they did, they would be mostly relying on garbage data anyways).

As a simpler solution, skip the ROM range scans (and the otherwise-
necessary range validation) during SEV-SNP guest early boot. The
potential SEV-SNP guest crash due to lack of ROM range validation is
thus avoided by simply not accessing the ROM range.

In most cases, skip the scans by overriding problematic x86_init
functions during sme_early_init() to SNP-safe variants, which can be
likened to x86_init overrides done for other platforms (ex: Xen); such
overrides also avoid the spread of cc_platform_has() checks throughout
the tree.

In the exceptional EISA case, still use cc_platform_has() for the
simplest change, given (1) checks for guest type (ex: Xen domain status)
are already performed here, and (2) these checks occur in a subsys
initcall instead of an x86_init function.

  [ bp: Massage commit message, remove "we"s. ]

Fixes: 9704c07bf9f7 ("x86/kernel: Validate ROM memory before accessing when SEV-SNP is active")
Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240313121546.2964854-1-kevinloughlin@google.com

The boot sequence evaluates CPUID information twice:

  1) During early boot

  2) When finalizing the early setup right before
     mitigations are selected and alternatives are patched.

In both cases the evaluation is stored in boot_cpu_data, but on UP the
copying of boot_cpu_data to the per CPU info of the boot CPU happens
between #1 and #2. So any update which happens in #2 is never propagated to
the per CPU info instance.

Consolidate the whole logic and copy boot_cpu_data right before applying
alternatives as that's the point where boot_cpu_data is in it's final
state and not supposed to change anymore.

This also removes the voodoo mb() from smp_prepare_cpus_common() which
had absolutely no purpose.

Fixes: 71eb4893cfaf ("x86/percpu: Cure per CPU madness on UP")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240322185305.127642785@linutronix.de

The only useful piece of arch/x86/kernel/topology.c is the definition
of arch_cpu_is_hotpluggable() that can be moved elsewhere (other
architectures tend to put it into setup.c), so do that and delete
the rest of the file.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/12422874.O9o76ZdvQC@kreacher