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Commit Graph

1002 Commits

Author SHA1 Message Date
Heiko Carstens
254b2fd02e s390/mm: provide minimal setup_per_cpu_areas() implementation
s390 allows to enable CONFIG_NUMA, mainly to enable a couple of system
calls which are only present if NUMA is enabled. The NUMA specific system
calls are required by a couple of applications, which wouldn't work if the
system calls wouldn't be present.

The NUMA implementation itself maps all CPUs and memory to node 0. A
special case is the generic percpu setup code, which doesn't expect an s390
like implementation and therefore emits a message/warning:
"percpu: cpu 0 has no node -1 or node-local memory".

In order to get rid of this message, and also to provide sane CPU to node
and CPU distance mappings implement a minimal setup_per_cpu_areas()
function, which is very close to the generic variant.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-11-23 16:22:21 +01:00
Jason A. Donenfeld
a251c17aa5 treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Matthew Wilcox (Oracle)
e7b6b990e5 s390: remove vma linked list walks
Use the VMA iterator instead.

Link: https://lkml.kernel.org/r/20220906194824.2110408-35-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:19 -07:00
Alexander Gordeev
9267bdd819 s390/mm: fix no previous prototype warnings in maccess.c
Fix -Wmissing-prototypes warnings caused by missing maccess.h include.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 2f0e8aae26 ("s390/mm: rework memcpy_real() to avoid DAT-off mode")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-16 18:36:25 +02:00
Alexander Gordeev
c0ceb94403 s390/mm,ptdump: add real memory copy page markers
Add "Real Memory Copy Area Start" and "Real Memory Copy Area End"
markers that fence the page used for real memory copying.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-14 16:46:01 +02:00
Alexander Gordeev
2f0e8aae26 s390/mm: rework memcpy_real() to avoid DAT-off mode
Function memcpy_real() is an univeral data mover that does not
require DAT mode to be able reading from a physical address.
Its advantage is an ability to read from any address, even
those for which no kernel virtual mapping exists.

Although memcpy_real() is interrupt-safe, there are no handlers
that make use of this function. The compiler instrumentation
have to be disabled and separate no-DAT stack used to allow
execution of the function once DAT mode is disabled.

Rework memcpy_real() to overcome these shortcomings. As result,
data copying (which is primarily reading out a crashed system
memory by a user process) is executed on a regular stack with
enabled interrupts. Also, use of memcpy_real_buf swap buffer
becomes unnecessary and the swapping is eliminated.

The above is achieved by using a fixed virtual address range
that spans a single page and remaps that page repeatedly when
memcpy_real() is called for a particular physical address.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-14 16:46:01 +02:00
Alexander Gordeev
5078775531 s390/smp,ptdump: add absolute lowcore markers
Add "Lowcore Area Start" and "Lowcore Area End" markers
that fence pages where absolute lowcore resides.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-14 16:46:00 +02:00
Alexander Gordeev
4df29d2b90 s390/smp: rework absolute lowcore access
Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework avoids the prefix page uninstalling and disabling
of normal and machine check interrupts when accessing the absolute
zero memory.

Although memcpy_absolute() routine can access the whole memory, it is
only used to update the absolute zero lowcore. This rework therefore
introduces a new mechanism for the absolute zero lowcore access and
scraps memcpy_absolute() routine for good.

Instead, an area is reserved in the virtual memory that is used for
the absolute lowcore access only. That area holds an array of 8KB
virtual mappings - one per CPU. Whenever a CPU is brought online, the
corresponding item is mapped to the real address of the previously
installed prefix page.

The absolute zero lowcore access works like this: a CPU calls the
new primitive get_abs_lowcore() to obtain its 8KB mapping as a
pointer to the struct lowcore. Virtual address references to that
pointer get translated to the real addresses of the prefix page,
which in turn gets swapped with the absolute zero memory addresses
due to prefixing. Once the pointer is not needed it must be released
with put_abs_lowcore() primitive:

	struct lowcore *abs_lc;
	unsigned long flags;

	abs_lc = get_abs_lowcore(&flags);
	abs_lc->... = ...;
	put_abs_lowcore(abs_lc, flags);

To ensure the described mechanism works large segment- and region-
table entries must be avoided for the 8KB mappings. Failure to do
so results in usage of Region-Frame Absolute Address (RFAA) or
Segment-Frame Absolute Address (SFAA) large page fields. In that
case absolute addresses would be used to address the prefix page
instead of the real ones and the prefixing would get bypassed.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-14 16:46:00 +02:00
Vasily Gorbik
d61bb30e43 Merge branch 'fixes' into features
* fixes:
  s390/smp: enforce lowcore protection on CPU restart
  s390/boot: fix absolute zero lowcore corruption on boot
  s390/hugetlb: fix prepare_hugepage_range() check for 2 GB hugepages
  s390: update defconfigs
  s390: fix nospec table alignments
  s390/mm: remove useless hugepage address alignment

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-14 16:41:21 +02:00
Gerald Schaefer
1a6baaa0db s390/hugetlb: switch to generic version of follow_huge_pud()
When pud-sized hugepages were introduced for s390, the generic version of
follow_huge_pud() was using pte_page() instead of pud_page().  This would
be wrong for s390, see also commit 9753412701 ("mm/hugetlb: use
pmd_page() in follow_huge_pmd()").  Therefore, and probably because not
all archs were supporting pud_page() at that time, a private version of
follow_huge_pud() was added for s390, correctly using pud_page().

Since commit 3a194f3f8a ("mm/hugetlb: make pud_huge() and
follow_huge_pud() aware of non-present pud entry"), the generic version of
follow_huge_pud() is now also using pud_page(), and in general behaves
similar to follow_huge_pmd().

Therefore we can now switch to the generic version and get rid of the
s390-specific follow_huge_pud().

Link: https://lkml.kernel.org/r/20220818135717.609eef8a@thinkpad
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Haiyue Wang <haiyue.wang@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:01 -07:00
Heiko Carstens
edcfc9c71b s390/ptdump: add missing amode31 markers
Add amode31 markers which makes a ro mapping in the middle of
nowhere in the kernel_page_tables output less magic.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-07 14:04:52 +02:00
Heiko Carstens
b193d2d4d0 s390/mm: split lowcore pages with set_memory_4k()
Use set_memory_4k() to split lowcore pages within the kernel mapping
instead of using the quite subtle !addr check within modify_pmd_table()
and modify_pud_table() to prevent large pages for address zero.

With this lowcore might be mapped with 1MB / 2GB frames and only later
will be split. This way this mapping is handled like every other.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-07 14:04:52 +02:00
Heiko Carstens
bf2ce3855c s390/mm: remove unused access parameter from do_fault_error()
Remove unused access parameter from do_fault_error() which also makes the
code a bit more readable since quite some callers can be simplified.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-08-30 22:00:33 +02:00
Gerald Schaefer
ff03b88467 s390/mm: remove useless hugepage address alignment
The failing address alignment to HPAGE_MASK in do_exception(), for
hugetlb faults, was useless from the beginning. With 2 GB hugepage
support it became wrong, but w/o further negative impact. Now it
could have negative performance impact because it breaks the cacheline
optimization for process_huge_page().

Therefore, remove it.

Note that we still have failing address alignment by HW to PAGE_SIZE,
for all page faults, not just hugetlb faults. So this patch will not
fix UFFD_FEATURE_EXACT_ADDRESS for userfaultfd handling. It will just
move the failing address for hugetlb faults a bit closer to the real
address, at 4K page granularity, similar to normal page faults.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-08-30 21:57:07 +02:00
Gerald Schaefer
41ac42f137 s390/mm: do not trigger write fault when vma does not allow VM_WRITE
For non-protection pXd_none() page faults in do_dat_exception(), we
call do_exception() with access == (VM_READ | VM_WRITE | VM_EXEC).
In do_exception(), vma->vm_flags is checked against that before
calling handle_mm_fault().

Since commit 92f842eac7 ("[S390] store indication fault optimization"),
we call handle_mm_fault() with FAULT_FLAG_WRITE, when recognizing that
it was a write access. However, the vma flags check is still only
checking against (VM_READ | VM_WRITE | VM_EXEC), and therefore also
calling handle_mm_fault() with FAULT_FLAG_WRITE in cases where the vma
does not allow VM_WRITE.

Fix this by changing access check in do_exception() to VM_WRITE only,
when recognizing write access.

Link: https://lkml.kernel.org/r/20220811103435.188481-3-david@redhat.com
Fixes: 92f842eac7 ("[S390] store indication fault optimization")
Cc: <stable@vger.kernel.org>
Reported-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-08-25 15:12:32 +02:00
Linus Torvalds
24cb958695 s390 updates for 5.20 merge window
- Rework copy_oldmem_page() callback to take an iov_iter.
   This includes few prerequisite updates and fixes to the
   oldmem reading code.
 
 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities,
   but also allows CPU facilities.
 
 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.
 
 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.
 
 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test.
 
 - Fix incorrect recovery of kretprobe modified return address in stacktrace.
 
 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.
 
 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as well
   as to implement more of the AP architecture.
 
 - Minor boot code cleanups.
 
 - Grammar and typo fixes to hmcdrv and tape drivers.
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Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

   This includes a few prerequisite updates and fixes to the oldmem
   reading code.

 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities, but
   also allows CPU facilities.

 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.

 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.

 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
   test.

 - Fix incorrect recovery of kretprobe modified return address in
   stacktrace.

 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.

 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as
   well as to implement more of the AP architecture.

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  Revert "s390/smp: enforce lowcore protection on CPU restart"
  Revert "s390/smp: rework absolute lowcore access"
  Revert "s390/smp,ptdump: add absolute lowcore markers"
  s390/unwind: fix fgraph return address recovery
  s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
  s390: add ELF note type for encrypted CPU state of a PV VCPU
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/setup: rearrange absolute lowcore initialization
  s390/boot: cleanup adjust_to_uv_max() function
  s390/smp: enforce lowcore protection on CPU restart
  s390/tape: fix comment typo
  s390/hmcdrv: fix Kconfig "its" grammar
  s390/docs: fix warnings for vfio_ap driver doc
  s390/docs: fix warnings for vfio_ap driver lock usage doc
  s390/crash: support multi-segment iterators
  s390/crash: use static swap buffer for copy_to_user_real()
  s390/crash: move copy_to_user_real() to crash_dump.c
  s390/zcore: fix race when reading from hardware system area
  s390/crash: fix incorrect number of bytes to copy to user space
  ...
2022-08-06 17:05:21 -07:00
Alexander Gordeev
5e441f61f5 Revert "s390/smp: rework absolute lowcore access"
This reverts commit 7d06fed77b.

This introduced vmem_mutex locking from vmem_map_4k_page()
function called from smp_reinit_ipl_cpu() with interrupts
disabled. While it is a pre-SMP early initcall no other CPUs
running in parallel nor other code taking vmem_mutex on this
boot stage - it still needs to be fixed.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-08-06 09:24:07 +02:00
Alexander Gordeev
3fb39cb7c5 Revert "s390/smp,ptdump: add absolute lowcore markers"
This reverts commit e409b7f191.

Commit 7d06fed77b ("s390/smp: rework absolute lowcore access")
introduced mutex lock with interrupts disabled. This commit is
a follow-up that needs to be reverted as well.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-08-06 09:13:28 +02:00
Linus Torvalds
6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Linus Torvalds
7447691ef9 xen: branch for v6.0-rc1
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Merge tag 'for-linus-6.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - a series fine tuning virtio support for Xen guests, including removal
   the now again unused "platform_has()" feature.

 - a fix for host admin triggered reboot of Xen guests

 - a simple spelling fix

* tag 'for-linus-6.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: don't require virtio with grants for non-PV guests
  kernel: remove platform_has() infrastructure
  virtio: replace restricted mem access flag with callback
  xen: Fix spelling mistake
  xen/manage: Use orderly_reboot() to reboot
2022-08-04 15:10:55 -07:00
Paolo Bonzini
63f4b21041 Merge remote-tracking branch 'kvm/next' into kvm-next-5.20
KVM/s390, KVM/x86 and common infrastructure changes for 5.20

x86:

* Permit guests to ignore single-bit ECC errors

* Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache

* Intel IPI virtualization

* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS

* PEBS virtualization

* Simplify PMU emulation by just using PERF_TYPE_RAW events

* More accurate event reinjection on SVM (avoid retrying instructions)

* Allow getting/setting the state of the speaker port data bit

* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent

* "Notify" VM exit (detect microarchitectural hangs) for Intel

* Cleanups for MCE MSR emulation

s390:

* add an interface to provide a hypervisor dump for secure guests

* improve selftests to use TAP interface

* enable interpretive execution of zPCI instructions (for PCI passthrough)

* First part of deferred teardown

* CPU Topology

* PV attestation

* Minor fixes

Generic:

* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple

x86:

* Use try_cmpxchg64 instead of cmpxchg64

* Bugfixes

* Ignore benign host accesses to PMU MSRs when PMU is disabled

* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis

* Port eager page splitting to shadow MMU as well

* Enable CMCI capability by default and handle injected UCNA errors

* Expose pid of vcpu threads in debugfs

* x2AVIC support for AMD

* cleanup PIO emulation

* Fixes for LLDT/LTR emulation

* Don't require refcounted "struct page" to create huge SPTEs

x86 cleanups:

* Use separate namespaces for guest PTEs and shadow PTEs bitmasks

* PIO emulation

* Reorganize rmap API, mostly around rmap destruction

* Do not workaround very old KVM bugs for L0 that runs with nesting enabled

* new selftests API for CPUID
2022-08-01 03:21:00 -04:00
Juergen Gross
a603002eea virtio: replace restricted mem access flag with callback
Instead of having a global flag to require restricted memory access
for all virtio devices, introduce a callback which can select that
requirement on a per-device basis.

For convenience add a common function returning always true, which can
be used for use cases like SEV.

Per default use a callback always returning false.

As the callback needs to be set in early init code already, add a
virtio anchor which is builtin in case virtio is enabled.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220622063838.8854-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2022-08-01 07:42:49 +02:00
Alexander Gordeev
e409b7f191 s390/smp,ptdump: add absolute lowcore markers
Add "Lowcore Area Start" and "Lowcore Area End" markers
that fence pages where absolute lowcore resides.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:24 +02:00
Alexander Gordeev
7d06fed77b s390/smp: rework absolute lowcore access
Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework avoids the prefix page uninstalling and disabling
of normal and machine check interrupts when accessing the absolute
zero memory.

Although memcpy_absolute() routine can access the whole memory, it is
only used to update the absolute zero lowcore. This rework therefore
introduces a new mechanism for the absolute zero lowcore access and
scraps memcpy_absolute() routine for good.

Instead, an area is reserved in the virtual memory that is used for
the absolute lowcore access only. That area holds an array of 8KB
virtual mappings - one per CPU. Whenever a CPU is brought online, the
corresponding item is mapped to the real address of the previously
installed prefix page.

The absolute zero lowcore access works like this: a CPU calls the
new primitive get_abs_lowcore() to obtain its 8KB mapping as a
pointer to the struct lowcore. Virtual address references to that
pointer get translated to the real addresses of the prefix page,
which in turn gets swapped with the absolute zero memory addresses
due to prefixing. Once the pointer is not needed it must be released
with put_abs_lowcore() primitive:

	struct lowcore *abs_lc;
	unsigned long flags;

	abs_lc = get_abs_lowcore(&flags);
	abs_lc->... = ...;
	put_abs_lowcore(abs_lc, flags);

To ensure the described mechanism works large segment- and region-
table entries must be avoided for the 8KB mappings. Failure to do
so results in usage of Region-Frame Absolute Address (RFAA) or
Segment-Frame Absolute Address (SFAA) large page fields. In that
case absolute addresses would be used to address the prefix page
instead of the real ones and the prefixing would get bypassed.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:23 +02:00
Alexander Gordeev
d6da673781 s390/crash: move copy_to_user_real() to crash_dump.c
Function copy_to_user_real() does not really belong to maccess.c.
It is only used for copying oldmem to user space, so let's move
it to the friends.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Link: https://lore.kernel.org/r/e8de968d40202d87caa09aef12e9c67ec23a1c1a.1658206891.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Anshuman Khandual
fd5d210fa6 s390/mm: enable ARCH_HAS_VM_GET_PAGE_PROT
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array.  Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.

Link: https://lkml.kernel.org/r/20220711070600.2378316-19-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:40 -07:00
Claudio Imbrenda
6f73517d0a KVM: s390: pv: refactor s390_reset_acc
Refactor s390_reset_acc so that it can be reused in upcoming patches.

We don't want to hold all the locks used in a walk_page_range for too
long, and the destroy page UVC does take some time to complete.
Therefore we quickly gather the pages to destroy, and then destroy them
without holding all the locks.

The new refactored function optionally allows to return early without
completing if a fatal signal is pending (and return and appropriate
error code). Two wrappers are provided to call the new function.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-5-imbrenda@linux.ibm.com
Message-Id: <20220628135619.32410-5-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-07-13 14:42:11 +00:00
Claudio Imbrenda
b108f7f0a2 KVM: s390: pv: handle secure storage exceptions for normal guests
With upcoming patches, normal guests might touch secure pages.

This patch extends the existing exception handler to convert the pages
to non secure also when the exception is triggered by a normal guest.

This can happen for example when a secure guest reboots; the first
stage of a secure guest is non secure, and in general a secure guest
can reboot into non-secure mode.

If the secure memory of the previous boot has not been cleared up
completely yet (which will be allowed to happen in an upcoming patch),
a non-secure guest might touch secure memory, which will need to be
handled properly.

This means that gmap faults must be handled and not cause termination
of the process. The handling is the same as userspace accesses, it's
enough to translate the gmap address to a user address and then let the
normal user fault code handle it.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-4-imbrenda@linux.ibm.com
Message-Id: <20220628135619.32410-4-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-07-13 14:42:11 +00:00
Claudio Imbrenda
a52c25848e KVM: s390: pv: handle secure storage violations for protected guests
A secure storage violation is triggered when a protected guest tries to
access secure memory that has been mapped erroneously, or that belongs
to a different protected guest or to the ultravisor.

With upcoming patches, protected guests will be able to trigger secure
storage violations in normal operation. This happens for example if a
protected guest is rebooted with deferred destroy enabled and the new
guest is also protected.

When the new protected guest touches pages that have not yet been
destroyed, and thus are accounted to the previous protected guest, a
secure storage violation is raised.

This patch adds handling of secure storage violations for protected
guests.

This exception is handled by first trying to destroy the page, because
it is expected to belong to a defunct protected guest where a destroy
should be possible. Note that a secure page can only be destroyed if
its protected VM does not have any CPUs, which only happens when the
protected VM is being terminated. If that fails, a normal export of
the page is attempted.

This means that pages that trigger the exception will be made
non-secure (in one way or another) before attempting to use them again
for a different secure guest.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-3-imbrenda@linux.ibm.com
Message-Id: <20220628135619.32410-3-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-07-13 14:42:11 +00:00
Claudio Imbrenda
faa2f72cb3 KVM: s390: pv: leak the topmost page table when destroy fails
Each secure guest must have a unique ASCE (address space control
element); we must avoid that new guests use the same page for their
ASCE, to avoid errors.

Since the ASCE mostly consists of the address of the topmost page table
(plus some flags), we must not return that memory to the pool unless
the ASCE is no longer in use.

Only a successful Destroy Secure Configuration UVC will make the ASCE
reusable again.

If the Destroy Configuration UVC fails, the ASCE cannot be reused for a
secure guest (either for the ASCE or for other memory areas). To avoid
a collision, it must not be used again. This is a permanent error and
the page becomes in practice unusable, so we set it aside and leak it.
On failure we already leak other memory that belongs to the ultravisor
(i.e. the variable and base storage for a guest) and not leaking the
topmost page table was an oversight.

This error (and thus the leakage) should not happen unless the hardware
is broken or KVM has some unknown serious bug.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: 29b40f105e ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling")
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-2-imbrenda@linux.ibm.com
Message-Id: <20220628135619.32410-2-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-07-13 14:42:11 +00:00
Peter Xu
d92725256b mm: avoid unnecessary page fault retires on shared memory types
I observed that for each of the shared file-backed page faults, we're very
likely to retry one more time for the 1st write fault upon no page.  It's
because we'll need to release the mmap lock for dirty rate limit purpose
with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()).

Then after that throttling we return VM_FAULT_RETRY.

We did that probably because VM_FAULT_RETRY is the only way we can return
to the fault handler at that time telling it we've released the mmap lock.

However that's not ideal because it's very likely the fault does not need
to be retried at all since the pgtable was well installed before the
throttling, so the next continuous fault (including taking mmap read lock,
walk the pgtable, etc.) could be in most cases unnecessary.

It's not only slowing down page faults for shared file-backed, but also add
more mmap lock contention which is in most cases not needed at all.

To observe this, one could try to write to some shmem page and look at
"pgfault" value in /proc/vmstat, then we should expect 2 counts for each
shmem write simply because we retried, and vm event "pgfault" will capture
that.

To make it more efficient, add a new VM_FAULT_COMPLETED return code just to
show that we've completed the whole fault and released the lock.  It's also
a hint that we should very possibly not need another fault immediately on
this page because we've just completed it.

This patch provides a ~12% perf boost on my aarch64 test VM with a simple
program sequentially dirtying 400MB shmem file being mmap()ed and these are
the time it needs:

  Before: 650.980 ms (+-1.94%)
  After:  569.396 ms (+-1.38%)

I believe it could help more than that.

We need some special care on GUP and the s390 pgfault handler (for gmap
code before returning from pgfault), the rest changes in the page fault
handlers should be relatively straightforward.

Another thing to mention is that mm_account_fault() does take this new
fault as a generic fault to be accounted, unlike VM_FAULT_RETRY.

I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do
not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping
them as-is.

Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vineet Gupta <vgupta@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>	[arm part]
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Will Deacon <will@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Helge Deller <deller@gmx.de>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:48:27 -07:00
Juergen Gross
3f9dfbebdc virtio: replace arch_has_restricted_virtio_memory_access()
Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>
2022-06-06 08:22:01 +02:00
Linus Torvalds
4ab6cfc4ad more s390 updates for 5.19 merge window
- Add Eric Farman as maintainer for s390 virtio drivers.
 
 - Improve machine check handling, and avoid incorrectly injecting a machine
   check into a kvm guest.
 
 - Add cond_resched() call to gmap page table walker in order to avoid
   possible huge latencies. Also use non-quiesing sske instruction to speed
   up storage key handling.
 
 - Add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP so s390 behaves similar like
   common code.
 
 - Get sie control block address from correct stack slot in perf event
   code. This fixes potential random memory accesses.
 
 - Change uaccess code so that the exception handler sets the result of
   get_user() and __get_kernel_nofault() to zero in case of a fault. Until
   now this was done via input parameters for inline assemblies. Doing it
   via fault handling is what most or even all other architectures are
   doing.
 
 - Couple of other small cleanups and fixes.
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Merge tag 's390-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:
 "Just a couple of small improvements, bug fixes and cleanups:

   - Add Eric Farman as maintainer for s390 virtio drivers.

   - Improve machine check handling, and avoid incorrectly injecting a
     machine check into a kvm guest.

   - Add cond_resched() call to gmap page table walker in order to avoid
     possible huge latencies. Also use non-quiesing sske instruction to
     speed up storage key handling.

   - Add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP so s390 behaves
     similar like common code.

   - Get sie control block address from correct stack slot in perf event
     code. This fixes potential random memory accesses.

   - Change uaccess code so that the exception handler sets the result
     of get_user() and __get_kernel_nofault() to zero in case of a
     fault. Until now this was done via input parameters for inline
     assemblies. Doing it via fault handling is what most or even all
     other architectures are doing.

   - Couple of other small cleanups and fixes"

* tag 's390-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/stack: add union to reflect kvm stack slot usages
  s390/stack: merge empty stack frame slots
  s390/uaccess: whitespace cleanup
  s390/uaccess: use __noreturn instead of __attribute__((noreturn))
  s390/uaccess: use exception handler to zero result on get_user() failure
  s390/uaccess: use symbolic names for inline assembler operands
  s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flag
  s390/mm: use non-quiescing sske for KVM switch to keyed guest
  s390/gmap: voluntarily schedule during key setting
  MAINTAINERS: Update s390 virtio-ccw
  s390/kexec: add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP
  s390/Kconfig.debug: fix indentation
  s390/Kconfig: fix indentation
  s390/perf: obtain sie_block from the right address
  s390: generate register offsets into pt_regs automatically
  s390: simplify early program check handler
  s390/crypto: fix scatterwalk_unmap() callers in AES-GCM
2022-06-03 13:57:50 -07:00
Heiko Carstens
454ede3f14 s390/uaccess: use exception handler to zero result on get_user() failure
Historically the uaccess code pre-initializes the result of get_user()
(and now also __get_kernel_nofault()) to zero and uses the result as
input parameter for inline assemblies. This is different to what most,
if not all, other architectures are doing, which set the result to
zero within the exception handler in case of a fault.

Use the new extable mechanism and handle zeroing of the result within
the exception handler in case of a fault.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01 12:03:17 +02:00
Christian Borntraeger
3ae11dbcfa s390/mm: use non-quiescing sske for KVM switch to keyed guest
The switch to a keyed guest does not require a classic sske as the other
guest CPUs are not accessing the key before the switch is complete.
By using the NQ SSKE things are faster especially with multiple guests.

Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Suggested-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01 12:03:16 +02:00
Christian Borntraeger
6d5946274d s390/gmap: voluntarily schedule during key setting
With large and many guest with storage keys it is possible to create
large latencies or stalls during initial key setting:

rcu: INFO: rcu_sched self-detected stall on CPU
rcu:   18-....: (2099 ticks this GP) idle=54e/1/0x4000000000000002 softirq=35598716/35598716 fqs=998
       (t=2100 jiffies g=155867385 q=20879)
Task dump for CPU 18:
CPU 1/KVM       R  running task        0 1030947 256019 0x06000004
Call Trace:
sched_show_task
rcu_dump_cpu_stacks
rcu_sched_clock_irq
update_process_times
tick_sched_handle
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
do_IRQ
ext_int_handler
ptep_zap_key

The mmap lock is held during the page walking but since this is a
semaphore scheduling is still possible. Same for the kvm srcu.
To minimize overhead do this on every segment table entry or large page.

Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-2-borntraeger@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01 12:03:16 +02:00
Linus Torvalds
3f306ea2e1 dma-mapping updates for Linux 5.19
- don't over-decrypt memory (Robin Murphy)
  - takes min align mask into account for the swiotlb max mapping size
    (Tianyu Lan)
  - use GFP_ATOMIC in dma-debug (Mikulas Patocka)
  - fix DMA_ATTR_NO_KERNEL_MAPPING on xen/arm (me)
  - don't fail on highmem CMA pages in dma_direct_alloc_pages (me)
  - cleanup swiotlb initialization and share more code with swiotlb-xen
    (me, Stefano Stabellini)
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Merge tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - don't over-decrypt memory (Robin Murphy)

 - takes min align mask into account for the swiotlb max mapping size
   (Tianyu Lan)

 - use GFP_ATOMIC in dma-debug (Mikulas Patocka)

 - fix DMA_ATTR_NO_KERNEL_MAPPING on xen/arm (me)

 - don't fail on highmem CMA pages in dma_direct_alloc_pages (me)

 - cleanup swiotlb initialization and share more code with swiotlb-xen
   (me, Stefano Stabellini)

* tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping: (23 commits)
  dma-direct: don't over-decrypt memory
  swiotlb: max mapping size takes min align mask into account
  swiotlb: use the right nslabs-derived sizes in swiotlb_init_late
  swiotlb: use the right nslabs value in swiotlb_init_remap
  swiotlb: don't panic when the swiotlb buffer can't be allocated
  dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC
  dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages
  swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm
  x86: remove cruft from <asm/dma-mapping.h>
  swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl
  swiotlb: merge swiotlb-xen initialization into swiotlb
  swiotlb: provide swiotlb_init variants that remap the buffer
  swiotlb: pass a gfp_mask argument to swiotlb_init_late
  swiotlb: add a SWIOTLB_ANY flag to lift the low memory restriction
  swiotlb: make the swiotlb_init interface more useful
  x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled
  x86: remove the IOMMU table infrastructure
  MIPS/octeon: use swiotlb_init instead of open coding it
  arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region
  swiotlb: rename swiotlb_late_init_with_default_size
  ...
2022-05-25 19:18:36 -07:00
Linus Torvalds
95fbef17e8 s390 updates for 5.19 merge window
- Make use of the IBM z16 processor activity instrumentation facility
   to count cryptography operations: add a new PMU device driver so
   that perf can make use of this.
 
 - Add new IBM z16 extended counter set to cpumf support.
 
 - Add vdso randomization support.
 
 - Add missing KCSAN instrumentation to barriers and spinlocks, which
   should make s390's KCSAN support complete.
 
 - Add support for IPL-complete-control facility: notify the hypervisor
   that kexec finished work and the kernel starts.
 
 - Improve error logging for PCI.
 
 - Various small changes to workaround llvm's integrated assembler
   limitations, and one bug, to make it finally possible to compile the
   kernel with llvm's integrated assembler. This also requires to raise
   the minimum clang version to 14.0.0.
 
 - Various other small enhancements, bug fixes, and cleanups all over
   the place.
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Merge tag 's390-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Make use of the IBM z16 processor activity instrumentation facility
   to count cryptography operations: add a new PMU device driver so that
   perf can make use of this.

 - Add new IBM z16 extended counter set to cpumf support.

 - Add vdso randomization support.

 - Add missing KCSAN instrumentation to barriers and spinlocks, which
   should make s390's KCSAN support complete.

 - Add support for IPL-complete-control facility: notify the hypervisor
   that kexec finished work and the kernel starts.

 - Improve error logging for PCI.

 - Various small changes to workaround llvm's integrated assembler
   limitations, and one bug, to make it finally possible to compile the
   kernel with llvm's integrated assembler. This also requires to raise
   the minimum clang version to 14.0.0.

 - Various other small enhancements, bug fixes, and cleanups all over
   the place.

* tag 's390-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
  s390/head: get rid of 31 bit leftovers
  scripts/min-tool-version.sh: raise minimum clang version to 14.0.0 for s390
  s390/boot: do not emit debug info for assembly with llvm's IAS
  s390/boot: workaround llvm IAS bug
  s390/purgatory: workaround llvm's IAS limitations
  s390/entry: workaround llvm's IAS limitations
  s390/alternatives: remove padding generation code
  s390/alternatives: provide identical sized orginal/alternative sequences
  s390/cpumf: add new extended counter set for IBM z16
  s390/preempt: disable __preempt_count_add() optimization for PROFILE_ALL_BRANCHES
  s390/stp: clock_delta should be signed
  s390/stp: fix todoff size
  s390/pai: add support for cryptography counters
  entry: Rename arch_check_user_regs() to arch_enter_from_user_mode()
  s390/compat: cleanup compat_linux.h header file
  s390/entry: remove broken and not needed code
  s390/boot: convert parmarea to C
  s390/boot: convert initial lowcore to C
  s390/ptrace: move short psw definitions to ptrace header file
  s390/head: initialize all new psws
  ...
2022-05-23 21:01:30 -07:00
Christian Borntraeger
a06afe8383 KVM: s390: vsie/gmap: reduce gmap_rmap overhead
there are cases that trigger a 2nd shadow event for the same
vmaddr/raddr combination. (prefix changes, reboots, some known races)
This will increase memory usages and it will result in long latencies
when cleaning up, e.g. on shutdown. To avoid cases with a list that has
hundreds of identical raddrs we check existing entries at insert time.
As this measurably reduces the list length this will be faster than
traversing the list at shutdown time.

In the long run several places will be optimized to create less entries
and a shrinker might be necessary.

Fixes: 4be130a084 ("s390/mm: add shadow gmap support")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20220429151526.1560-1-borntraeger@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-03 15:15:44 +02:00
Sven Schnelle
f2f47d0ef7 s390/mmap: increase stack/mmap gap to 128MB
This basically reverts commit 9e78a13bfb ("[S390] reduce miminum
gap between stack and mmap_base"). 32MB is not enough space
between stack and mmap for some programs. Given that compat
task aren't common these days, lets revert back to 128MB.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-25 13:54:14 +02:00
Christoph Hellwig
c6af2aa9ff swiotlb: make the swiotlb_init interface more useful
Pass a boolean flag to indicate if swiotlb needs to be enabled based on
the addressing needs, and replace the verbose argument with a set of
flags, including one to force enable bounce buffering.

Note that this patch removes the possibility to force xen-swiotlb use
with the swiotlb=force parameter on the command line on x86 (arm and
arm64 never supported that), but this interface will be restored shortly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2022-04-18 07:21:11 +02:00
Vasily Gorbik
731efc9613 s390: convert ".insn" encoding to instruction names
With z10 as minimum supported machine generation many ".insn" encodings
could be now converted to instruction names. There are couple of exceptions
- stfle is used from the als code built for z900 and cannot be converted
- few ".insn" directives encode unsupported instruction formats

The generated code is identical before/after this change.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-10 15:58:17 +01:00
Vasily Gorbik
4efd417f29 s390: raise minimum supported machine generation to z10
Machine generations up to z9 (released in May 2006) have been officially
out of service for several years now (z9 end of service - January 31, 2019).
No distributions build kernels supporting those old machine generations
anymore, except Debian, which seems to pick the oldest supported
generation. The team supporting Debian on s390 has been notified about
the change.

Raising minimum supported machine generation to z10 helps to reduce
maintenance cost and effectively remove code, which is not getting
enough testing coverage due to lack of older hardware and distributions
support. Besides that this unblocks some optimization opportunities and
allows to use wider instruction set in asm files for future features
implementation. Due to this change spectre mitigation and usercopy
implementations could be drastically simplified and many newer instructions
could be converted from ".insn" encoding to instruction names.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-10 15:58:17 +01:00
Heiko Carstens
484a8ed8b7 s390/extable: add dedicated uaccess handler
This is more or less a combination of commit 2e77a62cb3 ("arm64:
extable: add a dedicated uaccess handler") and commit 4b5305decc
("x86/extable: Extend extable functionality").

To describe the problem that needs to solved let's cite the full arm64
commit message:

------
For inline assembly, we place exception fixups out-of-line in the
`.fixup` section such that these are out of the way of the fast path.
This has a few drawbacks:

* Since the fixup code is anonymous, backtraces will symbolize fixups
  as offsets from the nearest prior symbol, currently
  `__entry_tramp_text_end`. This is confusing, and painful to debug
  without access to the relevant vmlinux.

* Since the exception handler adjusts the PC to execute the fixup, and
  the fixup uses a direct branch back into the function it fixes,
  backtraces of fixups miss the original function. This is confusing,
  and violates requirements for RELIABLE_STACKTRACE (and therefore
  LIVEPATCH).

* Inline assembly and associated fixups are generated from templates,
  and we have many copies of logically identical fixups which only
  differ in which specific registers are written to and which address
  is branched to at the end of the fixup. This is potentially wasteful
  of I-cache resources, and makes it hard to add additional logic to
  fixups without significant bloat.

This patch address all three concerns for inline uaccess fixups by
adding a dedicated exception handler which updates registers in
exception context and subsequent returns back into the function which
faulted, removing the need for fixups specialized to each faulting
instruction.

Other than backtracing, there should be no functional change as a result
of this patch.
------

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
3d66718cd6 s390/extable: convert to relative table with data
Follow arm64, riscv, and x86 and change extable layout to common
"relative table with data". This allows to get rid of s390 specific
code in sorttable.c.

The main difference to before is that extable entries do not contain a
relative function pointer anymore. Instead data and type fields are
added.

The type field is used to indicate which exception handler needs to be
called, while the data field is currently unused.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
46fee16f57 s390/extable: add and use fixup_exception helper function
Add and use fixup_exception helper function in order to remove the
duplicated exception handler fixup code at several places.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
0741ec112c s390/extable: move extable related functions to mm/extable.c
Just like arm64, riscv, and x86 move extable related functions to
mm/extable.c. This is currently only one function, but this will
change with subsequent changes.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
d09a307fde s390/extable: move EX_TABLE define to asm-extable.h
Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h
which is a lot less generic than the current linkage.h.

Also make sure that all files which contain EX_TABLE usages actually
include the new header file. This should make sure that the files
always compile and there won't be any random compile breakage due to
other header file dependencies.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
1952954569 s390/extable: search amode31 extable last
It is very unlikely that an exception happens within the amode31 text
section, therefore safe a couple of cycles for the common case, and
search the amode31 extable last.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00