Commit Graph

328 Commits

Author SHA1 Message Date
Nathan Chancellor
c0f98ea0e7 s390/boot: vmlinux.lds.S: handle commonly discarded sections
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings
from the various discardable sections that the kernel adds for build
purposes that are not needed at runtime:

  s390-linux-ld: warning: orphan section `.export_symbol' from `arch/s390/boot/decompressor.o' being placed in section `.export_symbol'
  s390-linux-ld: warning: orphan section `.discard.addressable' from `arch/s390/boot/decompressor.o' being placed in section `.discard.addressable'
  s390-linux-ld: warning: orphan section `.modinfo' from `arch/s390/boot/decompressor.o' being placed in section `.modinfo'

include/asm-generic/vmlinux.lds.h has a macro for easily discarding
these sections across the kernel named COMMON_DISCARDS, use it to clear
up the warnings.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-9-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:53 +01:00
Nathan Chancellor
6a4d37c886 s390/boot: vmlinux.lds.S: handle ELF required sections
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning around the '.comment'
section for each file in arch/s390/boot

  s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/als.o' being placed in section `.comment'
  s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/startup.o' being placed in section `.comment'
  s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/physmem_info.o' being placed in section `.comment'

include/asm-generic/vmlinux.lds.h has a macro for required ELF sections
not related to debugging named ELF_DETAILS, use it to clear up the
warnings.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-8-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:53 +01:00
Nathan Chancellor
ba6c26af1e s390/boot: vmlinux.lds.S: handle DWARF debug sections
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings for
each file in arch/s390/boot due to the boot linker script not handling
the DWARF debug sections:

  s390-linux-ld: warning: orphan section `.debug_line' from `arch/s390/boot/head.o' being placed in section `.debug_line'
  s390-linux-ld: warning: orphan section `.debug_info' from `arch/s390/boot/head.o' being placed in section `.debug_info'
  s390-linux-ld: warning: orphan section `.debug_abbrev' from `arch/s390/boot/head.o' being placed in section `.debug_abbrev'
  s390-linux-ld: warning: orphan section `.debug_aranges' from `arch/s390/boot/head.o' being placed in section `.debug_aranges'
  s390-linux-ld: warning: orphan section `.debug_str' from `arch/s390/boot/head.o' being placed in section `.debug_str'

include/asm-generic/vmlinux.lds.h has a macro for DWARF debug sections
named DWARF_DEBUG, use it to clear up the warnings.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-7-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:52 +01:00
Nathan Chancellor
64d590a24f s390/boot: vmlinux.lds.S: handle '.rela' sections
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several warnings from
arch/s390/boot/head.o due to the unhandled presence of '.rela' sections:

  s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'

These sections are unneeded for the decompressor and they are not
emitted in the binary currently. In a manner similar to other
architectures, coalesce the sections into '.rela.dyn' and ensure it is
zero sized, which is a safe/tested approach versus full discard.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-6-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:52 +01:00
Nathan Chancellor
b23ab303dd s390/boot: vmlinux.lds.S: handle '.init.text'
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning about the presence of
an '.init.text' section in arch/s390/boot:

  s390-linux-ld: warning: orphan section `.init.text' from `arch/s390/boot/sclp_early_core.o' being placed in section `.init.text'

arch/s390/boot/sclp_early_core.c includes a file from the main kernel
build, which picks up a usage of '__init' somewhere. For the
decompressed image, this section can just be coalesced into '.text'.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-5-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:52 +01:00
Nathan Chancellor
30226853d6 s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sections
When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around the
GOT and PLT sections:

  s390-linux-ld: warning: orphan section `.plt' from `arch/s390/kernel/head64.o' being placed in section `.plt'
  s390-linux-ld: warning: orphan section `.got' from `arch/s390/kernel/head64.o' being placed in section `.got'
  s390-linux-ld: warning: orphan section `.got.plt' from `arch/s390/kernel/head64.o' being placed in section `.got.plt'
  s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/kernel/head64.o' being placed in section `.iplt'
  s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/kernel/head64.o' being placed in section `.igot.plt'

  s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/boot/head.o' being placed in section `.iplt'
  s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/boot/head.o' being placed in section `.igot.plt'
  s390-linux-ld: warning: orphan section `.got' from `arch/s390/boot/head.o' being placed in section `.got'

Currently, only the '.got' section is actually emitted in the final
binary. In a manner similar to other architectures, put the '.got'
section near the '.data' section and coalesce the PLT sections,
checking that the final section is zero sized, which is a safe/tested
approach versus full discard.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-3-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:52 +01:00
Nathan Chancellor
2151fd9a6d s390/boot: add support for CONFIG_LD_ORPHAN_WARN
arch/s390/boot/vmlinux uses a different linker script and build rules
than the main vmlinux, so the '--orphan-handling' flag is not applied to
it. Add support for '--orphan-handling' so that all sections are
properly described in the linker script, which helps eliminate bugs
between linker implementations having different orphan section
heuristics.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-1-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14 13:50:52 +01:00
Alexander Gordeev
65f8780e2d s390/boot: always align vmalloc area on segment boundary
The size of vmalloc area depends from various factors
on boot and could be set to:

1. Default size as determined by VMALLOC_DEFAULT_SIZE macro;
2. One half of the virtual address space not occupied by
   modules and fixed mappings;
3. The size provided by user with vmalloc= kernel command
   line parameter;

In cases [1] and [2] the vmalloc area base address is aligned
on Region3 table type boundary, while in case [3] in might get
aligned on page boundary.

Limit the waste of page tables and always align vmalloc area
size and base address on segment boundary.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-11-22 14:07:28 +01:00
Heiko Carstens
a51324c430 s390/cmma: rework no-dat handling
Rework the way physical pages are set no-dat / dat:

The old way is:

- Rely on that all pages are initially marked "dat"
- Allocate page tables for the kernel mapping
- Enable dat
- Walk the whole kernel mapping and set PG_arch_1 bit in all struct pages
  that belong to pages of kernel page tables
- Walk all struct pages and test and clear the PG_arch_1 bit. If the bit is
  not set, set the page state to no-dat
- For all subsequent page table allocations, set the page state to dat
  (remove the no-dat state) on allocation time

Change this rather complex logic to a simpler approach:

- Set the whole physical memory (all pages) to "no-dat"
- Explicitly set those page table pages to "dat" which are part of the
  kernel image (e.g. swapper_pg_dir)
- For all subsequent page table allocations, set the page state to dat
  (remove the no-dat state) on allocation time

In result the code is simpler, and this also allows to get rid of one
odd usage of the PG_arch_1 bit.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-11-05 22:34:58 +01:00
Heiko Carstens
468a3bc2b7 s390/cmma: move parsing of cmma kernel parameter to early boot code
The "cmma=" kernel command line parameter needs to be parsed early for
upcoming changes. Therefore move the parsing code.

Note that EX_TABLE handling of cmma_test_essa() needs to be open-coded,
since the early boot code doesn't have infrastructure for handling expected
exceptions.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-11-05 22:34:57 +01:00
Linus Torvalds
e392ea4d4d s390 updates for the 6.7 merge window
- Get rid of private VM_FAULT flags
 
 - Add word-at-a-time implementation
 
 - Add DCACHE_WORD_ACCESS support
 
 - Cleanup control register handling
 
 - Disallow CPU hotplug of CPU 0 to simplify its handling complexity,
   following a similar restriction in x86
 
 - Optimize pai crypto map allocation
 
 - Update the list of crypto express EP11 coprocessor operation modes
 
 - Fixes and improvements for secure guests AP pass-through
 
 - Several fixes to address incorrect page marking for address translation
   with the "cmma no-dat" feature, preventing potential incorrect guest
   TLB flushes
 
 - Fix early IPI handling
 
 - Several virtual vs physical address confusion fixes
 
 - Various small fixes and improvements all over the code
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Merge tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Get rid of private VM_FAULT flags

 - Add word-at-a-time implementation

 - Add DCACHE_WORD_ACCESS support

 - Cleanup control register handling

 - Disallow CPU hotplug of CPU 0 to simplify its handling complexity,
   following a similar restriction in x86

 - Optimize pai crypto map allocation

 - Update the list of crypto express EP11 coprocessor operation modes

 - Fixes and improvements for secure guests AP pass-through

 - Several fixes to address incorrect page marking for address
   translation with the "cmma no-dat" feature, preventing potential
   incorrect guest TLB flushes

 - Fix early IPI handling

 - Several virtual vs physical address confusion fixes

 - Various small fixes and improvements all over the code

* tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (74 commits)
  s390/cio: replace deprecated strncpy with strscpy
  s390/sclp: replace deprecated strncpy with strtomem
  s390/cio: fix virtual vs physical address confusion
  s390/cio: export CMG value as decimal
  s390: delete the unused store_prefix() function
  s390/cmma: fix handling of swapper_pg_dir and invalid_pg_dir
  s390/cmma: fix detection of DAT pages
  s390/sclp: handle default case in sclp memory notifier
  s390/pai_crypto: remove per-cpu variable assignement in event initialization
  s390/pai: initialize event count once at initialization
  s390/pai_crypto: use PERF_ATTACH_TASK define for per task detection
  s390/mm: add missing arch_set_page_dat() call to gmap allocations
  s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc()
  s390/cmma: fix initial kernel address space page table walk
  s390/diag: add missing virt_to_phys() translation to diag224()
  s390/mm,fault: move VM_FAULT_ERROR handling to do_exception()
  s390/mm,fault: remove VM_FAULT_BADMAP and VM_FAULT_BADACCESS
  s390/mm,fault: remove VM_FAULT_SIGNAL
  s390/mm,fault: remove VM_FAULT_BADCONTEXT
  s390/mm,fault: simplify kfence fault handling
  ...
2023-11-03 10:17:22 -10:00
Vasily Gorbik
19ba9ead8a s390/vmem: remove unused variable
Fix the follow warning reported by sparse:

arch/s390/boot/vmem.c:170:15: warning: unused variable ‘entry’ [-Wunused-variable]
  170 |         pte_t entry;
      |               ^~~~~

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-10-16 13:04:09 +02:00
Vasily Gorbik
327899674e s390/kasan: handle DCSS mapping in memory holes
When physical memory is defined under z/VM using DEF STOR CONFIG, there
may be memory holes that are not hotpluggable memory. In such cases,
DCSS mapping could be placed in one of these memory holes. Subsequently,
attempting memory access to such DCSS mapping would result in a kasan
failure because there is no shadow memory mapping for it.

To maintain consistency with cases where DCSS mapping is positioned after
the kernel identity mapping, which is then covered by kasan zero shadow
mapping, handle the scenario above by populating zero shadow mapping
for memory holes where DCSS mapping could potentially be placed.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-10-16 13:03:05 +02:00
Heiko Carstens
99441a38c3 s390: use control register bit defines
Use control register bit defines instead of plain numbers where
possible.

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>
2023-09-19 13:26:57 +02:00
Heiko Carstens
527618abb9 s390/ctlreg: add struct ctlreg
Add struct ctlreg to enforce strict type checking / usage for control
register functions.

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>
2023-09-19 13:26:56 +02:00
Heiko Carstens
2372d39142 s390/ctlreg: use local_ctl_load() and local_ctl_store() where possible
Convert all single control register usages of __local_ctl_load() and
__local_ctl_store() to local_ctl_load() and local_ctl_store().

This also requires to change the type of some struct lowcore members
from __u64 to unsigned long.

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>
2023-09-19 13:26:56 +02:00
Heiko Carstens
8d5e98f8d6 s390/ctlreg: add local and system prefix to some functions
Add local and system prefix to some functions to clarify they change
control register contents on either the local CPU or the on all CPUs.

This results in the following API:

Two defines which load and save multiple control registers.
The defines correlate with the following C prototypes:

void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high);
void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high);

Two functions which locally set or clear one bit for a specified
control register:

void local_ctl_set_bit(unsigned int cr, unsigned int bit);
void local_ctl_clear_bit(unsigned int cr, unsigned int bit);

Two functions which set or clear one bit for a specified control
register on all CPUs:

void system_ctl_set_bit(unsigned int cr, unsigned int bit);
void system_ctl_clear_bit(unsigend int cr, unsigned int bit);

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>
2023-09-19 13:26:56 +02:00
Heiko Carstens
ebe1cd530f s390/ctlreg: rename ctl_reg.h to ctlreg.h
Rename ctl_reg.h to ctlreg.h so it matches not only ctlreg.c but also
other control register related function, union, and structure names,
which all come with a ctlreg prefix.

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>
2023-09-19 13:26:56 +02:00
Heiko Carstens
0c4d01f395 s390/ctlreg: move control register code to separate file
Control register handling has nothing to do with low level SMP code.
Move it to a separate file.

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>
2023-09-19 13:26:56 +02:00
Heiko Carstens
c0f1d47812 s390/mm: simplify kernel mapping setup
The kernel mapping is setup in two stages: in the decompressor map all
pages with RWX permissions, and within the kernel change all mappings to
their final permissions, where most of the mappings are changed from RWX to
RWNX.

Change this and map all pages RWNX from the beginning, however without
enabling noexec via control register modification. This means that
effectively all pages are used with RWX permissions like before. When the
final permissions have been applied to the kernel mapping enable noexec via
control register modification.

This allows to remove quite a bit of non-obvious code.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-30 11:03:27 +02:00
Heiko Carstens
b6f10e2f66 s390: remove "noexec" option
Do the same like x86 with commit 76ea0025a2 ("x86/cpu: Remove "noexec"")
and remove the "noexec" kernel command line option.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-30 11:03:27 +02:00
Alexander Gordeev
5cfdff02e9 s390/boot: fix multi-line comments style
Make multi-line comment style consistent across the source.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-16 15:13:03 +02:00
Alexander Gordeev
09cd4ffafb s390/boot: account Real Memory Copy and Lowcore areas
Real Memory Copy and (absolute) Lowcore areas are
not accounted when virtual memory layout is set up.

Fixes: 4df29d2b90 ("s390/smp: rework absolute lowcore access")
Fixes: 2f0e8aae26 ("s390/mm: rework memcpy_real() to avoid DAT-off mode")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-16 15:13:02 +02:00
Alexander Gordeev
a984f27ec2 s390/mm: define Real Memory Copy size and mask macros
Make Real Memory Copy area size and mask explicit.
This does not bring any functional change and only
needed for clarity.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-16 15:13:02 +02:00
Alexander Gordeev
8ddccc8a7d s390/boot: cleanup number of page table levels setup
The separate vmalloc area size check against _REGION2_SIZE
is needed in case user provided insanely large value using
vmalloc= kernel command line parameter. That could lead to
overflow and selecting 3 page table levels instead of 4.

Use size_add() for the overflow check and get rid of the
extra vmalloc area check.

With the current values of CONFIG_MAX_PHYSMEM_BITS and
PAGES_PER_SECTION the sum of maximal possible size of
identity mapping and vmemmap area (derived from these
macros) plus modules area size MODULES_LEN can not
overflow. Thus, that sum is used as first addend while
vmalloc area size is second addend for size_add().

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-16 15:13:02 +02:00
Alexander Gordeev
e7e828ebeb s390/mm: get rid of VMEM_MAX_PHYS macro
There are no users of VMEM_MAX_PHYS macro left, remove it.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Alexander Gordeev
94fd522069 s390/mm: rework arch_get_mappable_range() callback
As per description in mm/memory_hotplug.c platforms should define
arch_get_mappable_range() that provides maximum possible addressable
physical memory range for which the linear mapping could be created.

The current implementation uses VMEM_MAX_PHYS macro as the maximum
mappable physical address and it is simply a cast to vmemmap. Since
the address is in physical address space the natural upper limit of
MAX_PHYSMEM_BITS is honoured:

	vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS);

Further, to make sure the identity mapping would not overlay with
vmemmap, the size of identity mapping could be stripped like this:

	ident_map_size = min(ident_map_size, vmemmap_start);

Similarily, any other memory that could be added (e.g DCSS segment)
should not overlay with vmemmap as well and that is prevented by
using vmemmap (VMEM_MAX_PHYS macro) as the upper limit.

However, while the use of VMEM_MAX_PHYS brings the desired result
it actually poses two issues:

1. As described, vmemmap is handled as a physical address, although
   it is actually a pointer to struct page in virtual address space.

2. As vmemmap is a virtual address it could have been located
   anywhere in the virtual address space. However, the desired
   necessity to honour MAX_PHYSMEM_BITS limit prevents that.

Rework arch_get_mappable_range() callback in a way it does not
use VMEM_MAX_PHYS macro and does not confuse the notion of virtual
vs physical address spacees as result. That paves the way for moving
vmemmap elsewhere and optimizing the virtual address space layout.

Introduce max_mappable preserved boot variable and let function
setup_kernel_memory_layout() set it up. As result, the rest of the
code is does not need to know the virtual memory layout specifics.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Linus Torvalds
a452483508 s390 updates for 6.5 merge window part 2
- Fix virtual vs physical address confusion in vmem_add_range()
   and vmem_remove_range() functions.
 
 - Include <linux/io.h> instead of <asm/io.h> and <asm-generic/io.h>
   throughout s390 code.
 
 - Make all PSW related defines also available for assembler files.
   Remove PSW_DEFAULT_KEY define from uapi for that.
 
 - When adding an undefined symbol the build still succeeds, but
   userspace crashes trying to execute VDSO, because the symbol
   is not resolved. Add undefined symbols check to prevent that.
 
 - Use kvmalloc_array() instead of kzalloc() for allocaton of 256k
   memory when executing s390 crypto adapter IOCTL.
 
 - Add -fPIE flag to prevent decompressor misaligned symbol build
   error with clang.
 
 - Use .balign instead of .align everywhere. This is a no-op for s390,
   but with this there no mix in using .align and .balign anymore.
 
 - Filter out -mno-pic-data-is-text-relative flag when compiling
   kernel to prevent VDSO build error.
 
 - Rework entering of DAT-on mode on CPU restart to use PSW_KERNEL_BITS
   mask directly.
 
 - Do not retry administrative requests to some s390 crypto cards,
   since the firmware assumes replay attacks.
 
 - Remove most of the debug code, which is build in when kernel config
   option CONFIG_ZCRYPT_DEBUG is enabled.
 
 - Remove CONFIG_ZCRYPT_MULTIDEVNODES kernel config option and switch
   off the multiple devices support for the s390 zcrypt device driver.
 
 - With the conversion to generic entry machine checks are accounted
   to the current context instead of irq time. As result, the STCKF
   instruction at the beginning of the machine check handler and the
   lowcore member are no longer required, therefore remove it.
 
 - Fix various typos found with codespell.
 
 - Minor cleanups to CPU-measurement Counter and Sampling Facilities code.
 
 - Revert patch that removes VMEM_MAX_PHYS macro, since it causes
   a regression.
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Merge tag 's390-6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Alexander Gordeev:

 - Fix virtual vs physical address confusion in vmem_add_range() and
   vmem_remove_range() functions

 - Include <linux/io.h> instead of <asm/io.h> and <asm-generic/io.h>
   throughout s390 code

 - Make all PSW related defines also available for assembler files.
   Remove PSW_DEFAULT_KEY define from uapi for that

 - When adding an undefined symbol the build still succeeds, but
   userspace crashes trying to execute VDSO, because the symbol is not
   resolved. Add undefined symbols check to prevent that

 - Use kvmalloc_array() instead of kzalloc() for allocaton of 256k
   memory when executing s390 crypto adapter IOCTL

 - Add -fPIE flag to prevent decompressor misaligned symbol build error
   with clang

 - Use .balign instead of .align everywhere. This is a no-op for s390,
   but with this there no mix in using .align and .balign anymore

 - Filter out -mno-pic-data-is-text-relative flag when compiling kernel
   to prevent VDSO build error

 - Rework entering of DAT-on mode on CPU restart to use PSW_KERNEL_BITS
   mask directly

 - Do not retry administrative requests to some s390 crypto cards, since
   the firmware assumes replay attacks

 - Remove most of the debug code, which is build in when kernel config
   option CONFIG_ZCRYPT_DEBUG is enabled

 - Remove CONFIG_ZCRYPT_MULTIDEVNODES kernel config option and switch
   off the multiple devices support for the s390 zcrypt device driver

 - With the conversion to generic entry machine checks are accounted to
   the current context instead of irq time. As result, the STCKF
   instruction at the beginning of the machine check handler and the
   lowcore member are no longer required, therefore remove it

 - Fix various typos found with codespell

 - Minor cleanups to CPU-measurement Counter and Sampling Facilities
   code

 - Revert patch that removes VMEM_MAX_PHYS macro, since it causes a
   regression

* tag 's390-6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (25 commits)
  Revert "s390/mm: get rid of VMEM_MAX_PHYS macro"
  s390/cpum_sf: remove check on CPU being online
  s390/cpum_sf: handle casts consistently
  s390/cpum_sf: remove unnecessary debug statement
  s390/cpum_sf: remove parameter in call to pr_err
  s390/cpum_sf: simplify function setup_pmu_cpu
  s390/cpum_cf: remove unneeded debug statements
  s390/entry: remove mcck clock
  s390: fix various typos
  s390/zcrypt: remove ZCRYPT_MULTIDEVNODES kernel config option
  s390/zcrypt: do not retry administrative requests
  s390/zcrypt: cleanup some debug code
  s390/entry: rework entering DAT-on mode on CPU restart
  s390/mm: fence off VM macros from asm and linker
  s390: include linux/io.h instead of asm/io.h
  s390/ptrace: make all psw related defines also available for asm
  s390/ptrace: remove PSW_DEFAULT_KEY from uapi
  s390/vdso: filter out mno-pic-data-is-text-relative cflag
  s390: consistently use .balign instead of .align
  s390/decompressor: fix misaligned symbol build error
  ...
2023-07-06 13:18:30 -07:00
Alexander Gordeev
54372cf043 Revert "s390/mm: get rid of VMEM_MAX_PHYS macro"
This reverts commit 456be42aa7.

The assumption VMEM_MAX_PHYS should match ident_map_size
is wrong. At least discontiguous saved segments (DCSS)
could be loaded at addresses beyond ident_map_size and
dcssblk device driver might fail as result.

Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-07-04 07:46:26 +02:00
Linus Torvalds
e8069f5a8e ARM64:
* Eager page splitting optimization for dirty logging, optionally
   allowing for a VM to avoid the cost of hugepage splitting in the stage-2
   fault path.
 
 * Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with
   services that live in the Secure world. pKVM intervenes on FF-A calls
   to guarantee the host doesn't misuse memory donated to the hyp or a
   pKVM guest.
 
 * Support for running the split hypervisor with VHE enabled, known as
   'hVHE' mode. This is extremely useful for testing the split
   hypervisor on VHE-only systems, and paves the way for new use cases
   that depend on having two TTBRs available at EL2.
 
 * Generalized framework for configurable ID registers from userspace.
   KVM/arm64 currently prevents arbitrary CPU feature set configuration
   from userspace, but the intent is to relax this limitation and allow
   userspace to select a feature set consistent with the CPU.
 
 * Enable the use of Branch Target Identification (FEAT_BTI) in the
   hypervisor.
 
 * Use a separate set of pointer authentication keys for the hypervisor
   when running in protected mode, as the host is untrusted at runtime.
 
 * Ensure timer IRQs are consistently released in the init failure
   paths.
 
 * Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps
   (FEAT_EVT), as it is a register commonly read from userspace.
 
 * Erratum workaround for the upcoming AmpereOne part, which has broken
   hardware A/D state management.
 
 RISC-V:
 
 * Redirect AMO load/store misaligned traps to KVM guest
 
 * Trap-n-emulate AIA in-kernel irqchip for KVM guest
 
 * Svnapot support for KVM Guest
 
 s390:
 
 * New uvdevice secret API
 
 * CMM selftest and fixes
 
 * fix racy access to target CPU for diag 9c
 
 x86:
 
 * Fix missing/incorrect #GP checks on ENCLS
 
 * Use standard mmu_notifier hooks for handling APIC access page
 
 * Drop now unnecessary TR/TSS load after VM-Exit on AMD
 
 * Print more descriptive information about the status of SEV and SEV-ES during
   module load
 
 * Add a test for splitting and reconstituting hugepages during and after
   dirty logging
 
 * Add support for CPU pinning in demand paging test
 
 * Add support for AMD PerfMonV2, with a variety of cleanups and minor fixes
   included along the way
 
 * Add a "nx_huge_pages=never" option to effectively avoid creating NX hugepage
   recovery threads (because nx_huge_pages=off can be toggled at runtime)
 
 * Move handling of PAT out of MTRR code and dedup SVM+VMX code
 
 * Fix output of PIC poll command emulation when there's an interrupt
 
 * Add a maintainer's handbook to document KVM x86 processes, preferred coding
   style, testing expectations, etc.
 
 * Misc cleanups, fixes and comments
 
 Generic:
 
 * Miscellaneous bugfixes and cleanups
 
 Selftests:
 
 * Generate dependency files so that partial rebuilds work as expected
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Eager page splitting optimization for dirty logging, optionally
     allowing for a VM to avoid the cost of hugepage splitting in the
     stage-2 fault path.

   - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact
     with services that live in the Secure world. pKVM intervenes on
     FF-A calls to guarantee the host doesn't misuse memory donated to
     the hyp or a pKVM guest.

   - Support for running the split hypervisor with VHE enabled, known as
     'hVHE' mode. This is extremely useful for testing the split
     hypervisor on VHE-only systems, and paves the way for new use cases
     that depend on having two TTBRs available at EL2.

   - Generalized framework for configurable ID registers from userspace.
     KVM/arm64 currently prevents arbitrary CPU feature set
     configuration from userspace, but the intent is to relax this
     limitation and allow userspace to select a feature set consistent
     with the CPU.

   - Enable the use of Branch Target Identification (FEAT_BTI) in the
     hypervisor.

   - Use a separate set of pointer authentication keys for the
     hypervisor when running in protected mode, as the host is untrusted
     at runtime.

   - Ensure timer IRQs are consistently released in the init failure
     paths.

   - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization
     Traps (FEAT_EVT), as it is a register commonly read from userspace.

   - Erratum workaround for the upcoming AmpereOne part, which has
     broken hardware A/D state management.

  RISC-V:

   - Redirect AMO load/store misaligned traps to KVM guest

   - Trap-n-emulate AIA in-kernel irqchip for KVM guest

   - Svnapot support for KVM Guest

  s390:

   - New uvdevice secret API

   - CMM selftest and fixes

   - fix racy access to target CPU for diag 9c

  x86:

   - Fix missing/incorrect #GP checks on ENCLS

   - Use standard mmu_notifier hooks for handling APIC access page

   - Drop now unnecessary TR/TSS load after VM-Exit on AMD

   - Print more descriptive information about the status of SEV and
     SEV-ES during module load

   - Add a test for splitting and reconstituting hugepages during and
     after dirty logging

   - Add support for CPU pinning in demand paging test

   - Add support for AMD PerfMonV2, with a variety of cleanups and minor
     fixes included along the way

   - Add a "nx_huge_pages=never" option to effectively avoid creating NX
     hugepage recovery threads (because nx_huge_pages=off can be toggled
     at runtime)

   - Move handling of PAT out of MTRR code and dedup SVM+VMX code

   - Fix output of PIC poll command emulation when there's an interrupt

   - Add a maintainer's handbook to document KVM x86 processes,
     preferred coding style, testing expectations, etc.

   - Misc cleanups, fixes and comments

  Generic:

   - Miscellaneous bugfixes and cleanups

  Selftests:

   - Generate dependency files so that partial rebuilds work as
     expected"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (153 commits)
  Documentation/process: Add a maintainer handbook for KVM x86
  Documentation/process: Add a label for the tip tree handbook's coding style
  KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index
  RISC-V: KVM: Remove unneeded semicolon
  RISC-V: KVM: Allow Svnapot extension for Guest/VM
  riscv: kvm: define vcpu_sbi_ext_pmu in header
  RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC
  RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel emulation of AIA APLIC
  RISC-V: KVM: Implement device interface for AIA irqchip
  RISC-V: KVM: Skeletal in-kernel AIA irqchip support
  RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero
  RISC-V: KVM: Add APLIC related defines
  RISC-V: KVM: Add IMSIC related defines
  RISC-V: KVM: Implement guest external interrupt line management
  KVM: x86: Remove PRIx* definitions as they are solely for user space
  s390/uv: Update query for secret-UVCs
  s390/uv: replace scnprintf with sysfs_emit
  s390/uvdevice: Add 'Lock Secret Store' UVC
  ...
2023-07-03 15:32:22 -07:00
Heiko Carstens
cada938a01 s390: fix various typos
Fix various typos found with codespell.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-07-03 11:19:42 +02:00
Heiko Carstens
27d45655fa s390: consistently use .balign instead of .align
The .align directive has inconsistent behavior across architectures. Use
.balign instead everywhere. This is a no-op for s390, but with this there
is no mix in using .align and .balign anymore.

Future code is supposed to use only .balign.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-06-28 13:57:09 +02:00
Alexander Gordeev
456be42aa7 s390/mm: get rid of VMEM_MAX_PHYS macro
VMEM_MAX_PHYS is supposed to be the highest physical
address that can be added to the identity mapping.
It should match ident_map_size, which has the same
meaning. However, unlike ident_map_size it is not
adjusted against various limiting factors (see the
comment to setup_ident_map_size() function). That
renders all checks against VMEM_MAX_PHYS invalid.

Further, VMEM_MAX_PHYS is currently set to vmemmap,
which is an address in virtual memory space. However,
it gets compared against physical addresses in various
locations. That works, because both address spaces
are the same on s390, but otherwise it is wrong.

Instead of fixing VMEM_MAX_PHYS misuse and semantics
just remove it.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-06-28 13:57:08 +02:00
Alexander Gordeev
3e8261003b s390/kasan: avoid short by one page shadow memory
Kernel Address Sanitizer uses 3 bits per byte to
encode memory. That is the number of bits the start
and end address of a memory range is shifted right
when the corresponding shadow memory is created for
that memory range.

The used memory mapping routine expects page-aligned
addresses, while the above described 3-bit shift might
turn the shadow memory range start and end boundaries
into non-page-aligned in case the size of the original
memory range is less than (PAGE_SIZE << 3). As result,
the resulting shadow memory range could be short on one
page.

Align on page boundary the start and end addresses when
mapping a shadow memory range and avoid the described
issue in the future.

Note, that does not fix a real problem, since currently
no virtual regions of size less than (PAGE_SIZE << 3)
exist.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-06-20 19:52:13 +02:00
Steffen Eiden
db54dfc9f7 s390/uv: Update query for secret-UVCs
Update the query struct such that secret-UVC related
information can be parsed.
Add sysfs files for these new values.

'supp_add_secret_req_ver' notes the supported versions for the
Add Secret UVC. Bit 0 indicates that version 0x100 is supported,
bit 1 indicates 0x200, and so on.

'supp_add_secret_pcf' notes the supported plaintext flags for
the Add Secret UVC.

'supp_secret_types' notes the supported types of secrets.
Bit 0 indicates secret type 1, bit 1 indicates type 2, and so on.

'max_secrets' notes the maximum amount of secrets the secret store can
store per pv guest.

Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20230615100533.3996107-8-seiden@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20230615100533.3996107-8-seiden@linux.ibm.com>
2023-06-16 11:08:09 +02:00
Heiko Carstens
81e8479649 s390/mm: fix direct map accounting
Commit bb1520d581 ("s390/mm: start kernel with DAT enabled") did not
implement direct map accounting in the early page table setup code. In
result the reported values are bogus now:

$cat /proc/meminfo
...
DirectMap4k:        5120 kB
DirectMap1M:    18446744073709546496 kB
DirectMap2G:           0 kB

Fix this by adding the missing accounting. The result looks sane again:

$cat /proc/meminfo
...
DirectMap4k:        6156 kB
DirectMap1M:     2091008 kB
DirectMap2G:     6291456 kB

Fixes: bb1520d581 ("s390/mm: start kernel with DAT enabled")
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>
2023-04-13 17:36:28 +02:00
Heiko Carstens
07fdd6627f s390/mm: rename POPULATE_ONE2ONE to POPULATE_DIRECT
Architectures generally use the "direct map" wording for mapping the whole
physical memory. Use that wording as well in arch/s390/boot/vmem.c, instead
of "one to one" in order to avoid confusion.

This also matches what is already done in arch/s390/mm/vmem.c.

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>
2023-04-13 17:36:28 +02:00
Marc Hartmayer
d24e18ef7e s390/boot: improve install.sh script
Use proper quoting for the variables and explicitly distinguish between
command options and positional arguments.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:28 +02:00
Vasily Gorbik
b3e0423c4e s390/kaslr: randomize amode31 base address
When the KASLR is enabled, randomize the base address of the amode31 image
within the first 2 GB, similar to the approach taken for the vmlinux
image. This makes it harder to predict the location of amode31 data
and code.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:27 +02:00
Vasily Gorbik
6e259bc5a1 s390/kaslr: generalize and improve random base distribution
Improve the distribution algorithm of random base address to ensure
a uniformity among all suitable addresses. To generate a random value
once, and to build a continuous range in which every value is suitable,
count all the suitable addresses (referred to as positions) that can be
used as a base address. The positions are counted by iterating over the
usable memory ranges. For each range that is big enough to accommodate
the image, count all the suitable addresses where the image can be placed,
while taking reserved memory ranges into consideration.

A new function "iterate_valid_positions()" has dual purpose. Firstly, it
is called to count the positions in a given memory range, and secondly,
to convert a random position back to an address.

"get_random_base()" has been replaced with more generic
"randomize_within_range()" which now could be called for randomizing
base addresses not just for the kernel image.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:27 +02:00
Vasily Gorbik
898435203c s390/boot: pin amode31 default lma
The special amode31 part of the kernel must always remain below 2Gb. Place
it just under vmlinux.default_lma by default, which makes it easier to
debug amode31 as its default lma is known 0x10000 - 0x3000 (currently,
amode31's size is 3 pages). This location is always available as it is
originally occupied by the vmlinux archive.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:27 +02:00
Vasily Gorbik
a1d2d9cbaf s390/boot: do not change default_lma
The current modification of the default_lma is illogical and should be
avoided. It would be more appropriate to introduce and utilize a new
variable vmlinux_lma instead, so that default_lma remains unchanged and
at its original "default" value of 0x100000.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:27 +02:00
Heiko Carstens
bb87190c9d s390/kaslr: provide kaslr_enabled() function
Just like other architectures provide a kaslr_enabled() function, instead
of directly accessing a global variable.

Also pass the renamed __kaslr_enabled variable from the decompressor to the
kernel, so that kalsr_enabled() is available there too. This will be used
by a subsequent patch which randomizes the module base load address.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-13 17:36:25 +02:00
Vasily Gorbik
557b19709d s390/kasan: move shadow mapping to decompressor
Since regular paging structs are initialized in decompressor already
move KASAN shadow mapping to decompressor as well. This helps to avoid
allocating KASAN required memory in 1 large chunk, de-duplicate paging
structs creation code and start the uncompressed kernel with KASAN
instrumentation right away. This also allows to avoid all pitfalls
accidentally calling KASAN instrumented code during KASAN initialization.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:02:51 +01:00
Vasily Gorbik
f913a66004 s390/boot: rework decompressor reserved tracking
Currently several approaches for finding unused memory in decompressor
are utilized. While "safe_addr" grows towards higher addresses, vmem
code allocates paging structures top down. The former requires careful
ordering. In addition to that ipl report handling code verifies potential
intersections with secure boot certificates on its own. Neither of two
approaches are memory holes aware and consistent with each other in low
memory conditions.

To solve that, existing approaches are generalized and combined
together, as well as online memory ranges are now taken into
consideration.

physmem_info has been extended to contain reserved memory ranges. New
set of functions allow to handle reserves and find unused memory.
All reserves and memory allocations are "typed". In case of out of
memory condition decompressor fails with detailed info on current
reserved ranges and usable online memory.

Linux version 6.2.0 ...
Kernel command line: ... mem=100M
Our of memory allocating 100000 bytes 100000 aligned in range 0:5800000
Reserved memory ranges:
0000000000000000 0000000003e33000 DECOMPRESSOR
0000000003f00000 00000000057648a3 INITRD
00000000063e0000 00000000063e8000 VMEM
00000000063eb000 00000000063f4000 VMEM
00000000063f7800 0000000006400000 VMEM
0000000005800000 0000000006300000 KASAN
Usable online memory ranges (info source: sclp read info [3]):
0000000000000000 0000000006400000
Usable online memory total: 6400000 Reserved: 61b10a3 Free: 24ef5d
Call Trace:
(sp:000000000002bd58 [<0000000000012a70>] physmem_alloc_top_down+0x60/0x14c)
 sp:000000000002bdc8 [<0000000000013756>] _pa+0x56/0x6a
 sp:000000000002bdf0 [<0000000000013bcc>] pgtable_populate+0x45c/0x65e
 sp:000000000002be90 [<00000000000140aa>] setup_vmem+0x2da/0x424
 sp:000000000002bec8 [<0000000000011c20>] startup_kernel+0x428/0x8b4
 sp:000000000002bf60 [<00000000000100f4>] startup_normal+0xd4/0xd4

physmem_alloc_range allows to find free memory in specified range. It
should be used for one time allocations only like finding position for
amode31 and vmlinux.
physmem_alloc_top_down can be used just like physmem_alloc_range, but
it also allows multiple allocations per type and tries to merge sequential
allocations together. Which is useful for paging structures allocations.
If sequential allocations cannot be merged together they are "chained",
allowing easy per type reserved ranges enumeration and migration to
memblock later. Extra "struct reserved_range" allocated for chaining are
not tracked or reserved but rely on the fact that both
physmem_alloc_range and physmem_alloc_top_down search for free memory
only below current top down allocator position. All reserved ranges
should be transferred to memblock before memblock allocations are
enabled.

The startup code has been reordered to delay any memory allocations until
online memory ranges are detected and occupied memory ranges are marked as
reserved to be excluded from follow-up allocations.
Ipl report certificates are a special case, ipl report certificates list
is checked together with other memory reserves until certificates are
saved elsewhere.
KASAN required memory for shadow memory allocation and mapping is reserved
as 1 large chunk which is later passed to KASAN early initialization code.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:02:50 +01:00
Vasily Gorbik
8c37cb7d4f s390/boot: rename mem_detect to physmem_info
In preparation to extending mem_detect with additional information like
reserved ranges rename it to more generic physmem_info. This new naming
also help to avoid confusion by using more exact terms like "physmem
online ranges", etc.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:02:50 +01:00
Vasily Gorbik
53fcc7dbf1 s390/boot: remove non-functioning image bootable check
check_image_bootable() has been introduced with commit 627c9b6205
("s390/boot: block uncompressed vmlinux booting attempts") to make sure
that users don't try to boot uncompressed vmlinux ELF image in qemu. It
used to be possible quite some time ago. That commit prevented confusion
with uncompressed vmlinux image starting to boot and even printing
kernel messages until it crashed. Users might have tried to report the
problem without realizing they are doing something which was not intended.
Since commit f1d3c53237 ("s390/boot: move sclp early buffer from fixed
address in asm to C") check_image_bootable() doesn't function properly
anymore, as well as booting uncompressed vmlinux image in qemu doesn't
really produce any output and crashes. Moving forward it doesn't make
sense to fix check_image_bootable() anymore, so simply remove it.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:02:50 +01:00
Sven Schnelle
a52e5cdbe8 s390/ipl: add missing intersection check to ipl_report handling
The code which handles the ipl report is searching for a free location
in memory where it could copy the component and certificate entries to.
It checks for intersection between the sections required for the kernel
and the component/certificate data area, but fails to check whether
the data structures linking these data areas together intersect.

This might cause the iplreport copy code to overwrite the iplreport
itself. Fix this by adding two addtional intersection checks.

Cc: <stable@vger.kernel.org>
Fixes: 9641b8cc73 ("s390/ipl: read IPL report at early boot")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13 09:15:11 +01:00
Vasily Gorbik
9b5c37bbf6 s390/decompressor: add link map saving
Produce arch/s390/boot/vmlinux.map link map for the decompressor, when
CONFIG_VMLINUX_MAP option is enabled.

Link map is quite useful during making kernel changes related to how
the decompressor is composed and debugging linker scripts.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-02-28 13:19:06 +01:00
Vasily Gorbik
af0735269b s390/mem_detect: do not truncate online memory ranges info
Commit bf64f0517e ("s390/mem_detect: handle online memory limit
just once") introduced truncation of mem_detect online ranges
based on identity mapping size. For kdump case however the full
set of online memory ranges has to be feed into memblock_physmem_add
so that crashed system memory could be extracted.

Instead of truncating introduce a "usable limit" which is respected by
mem_detect api. Also add extra online memory ranges iterator which still
provides full set of online memory ranges disregarding the "usable limit".

Fixes: bf64f0517e ("s390/mem_detect: handle online memory limit just once")
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-02-14 11:45:40 +01:00