Commit Graph

436 Commits

Author SHA1 Message Date
Linus Torvalds
c993e07be0 Merge tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:

 - convert arm32 to the common dma-direct code (Arnd Bergmann, Robin
   Murphy, Christoph Hellwig)

 - restructure the PCIe peer to peer mapping support (Logan Gunthorpe)

 - allow the IOMMU code to communicate an optional DMA mapping length
   and use that in scsi and libata (John Garry)

 - split the global swiotlb lock (Tianyu Lan)

 - various fixes and cleanup (Chao Gao, Dan Carpenter, Dongli Zhang,
   Lukas Bulwahn, Robin Murphy)

* tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma-mapping: (45 commits)
  swiotlb: fix passing local variable to debugfs_create_ulong()
  dma-mapping: reformat comment to suppress htmldoc warning
  PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg()
  RDMA/rw: drop pci_p2pdma_[un]map_sg()
  RDMA/core: introduce ib_dma_pci_p2p_dma_supported()
  nvme-pci: convert to using dma_map_sgtable()
  nvme-pci: check DMA ops when indicating support for PCI P2PDMA
  iommu/dma: support PCI P2PDMA pages in dma-iommu map_sg
  iommu: Explicitly skip bus address marked segments in __iommu_map_sg()
  dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support
  dma-direct: support PCI P2PDMA pages in dma-direct map_sg
  dma-mapping: allow EREMOTEIO return code for P2PDMA transfers
  PCI/P2PDMA: Introduce helpers for dma_map_sg implementations
  PCI/P2PDMA: Attempt to set map_type if it has not been set
  lib/scatterlist: add flag for indicating P2PDMA segments in an SGL
  swiotlb: clean up some coding style and minor issues
  dma-mapping: update comment after dmabounce removal
  scsi: sd: Add a comment about limiting max_sectors to shost optimal limit
  ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors
  scsi: scsi_transport_sas: cap shost opt_sectors according to DMA optimal limit
  ...
2022-08-06 10:56:45 -07:00
Linus Torvalds
9e2f402336 Merge tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Dave Hansen:
 "A set of x86/sgx changes focused on implementing the "SGX2" features,
  plus a minor cleanup:

   - SGX2 ISA support which makes enclave memory management much more
     dynamic. For instance, enclaves can now change enclave page
     permissions on the fly.

   - Removal of an unused structure member"

* tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/sgx: Drop 'page_index' from sgx_backing
  selftests/sgx: Page removal stress test
  selftests/sgx: Test reclaiming of untouched page
  selftests/sgx: Test invalid access to removed enclave page
  selftests/sgx: Test faulty enclave behavior
  selftests/sgx: Test complete changing of page type flow
  selftests/sgx: Introduce TCS initialization enclave operation
  selftests/sgx: Introduce dynamic entry point
  selftests/sgx: Test two different SGX2 EAUG flows
  selftests/sgx: Add test for TCS page permission changes
  selftests/sgx: Add test for EPCM permission changes
  Documentation/x86: Introduce enclave runtime management section
  x86/sgx: Free up EPC pages directly to support large page ranges
  x86/sgx: Support complete page removal
  x86/sgx: Support modifying SGX page type
  x86/sgx: Tighten accessible memory range after enclave initialization
  x86/sgx: Support adding of pages to an initialized enclave
  x86/sgx: Support restricting of enclave page permissions
  x86/sgx: Support VA page allocation without reclaiming
  x86/sgx: Export sgx_encl_page_alloc()
  ...
2022-08-05 10:47:40 -07:00
Linus Torvalds
ab17c0cd37 Merge tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull efivars sysfs interface removal from Ard Biesheuvel:
 "Remove the obsolete 'efivars' sysfs based interface to the EFI
  variable store, now that all users have moved to the efivarfs pseudo
  file system, which was created ~10 years ago to address some
  fundamental shortcomings in the sysfs based driver.

  Move the 'business logic' related to which EFI variables are important
  and may affect the boot flow from the efivars support layer into the
  efivarfs pseudo file system, so it is no longer exposed to other parts
  of the kernel"

* tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: vars: Move efivar caching layer into efivarfs
  efi: vars: Switch to new wrapper layer
  efi: vars: Remove deprecated 'efivars' sysfs interface
2022-08-03 14:41:36 -07:00
Mauro Carvalho Chehab
d6a21f2d73 objtool: update objtool.txt references
Changeset a8e35fece4 ("objtool: Update documentation")
renamed: tools/objtool/Documentation/stack-validation.txt
to: tools/objtool/Documentation/objtool.txt.

Update the cross-references accordingly.

Fixes: a8e35fece4 ("objtool: Update documentation")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/ec285ece6348a5be191aebe45f78d06b3319056b.1656234456.git.mchehab@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-07-07 13:10:00 -06:00
Reinette Chatre
629b5155d0 Documentation/x86: Introduce enclave runtime management section
Enclave runtime management is introduced following the pattern
of the section describing enclave building. Provide a brief
summary of enclave runtime management, pointing to the functions
implementing the ioctl()s that will contain details within their
kernel-doc.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/1da0b9a938b28e68e6870ebd5291490d680e700b.1652137848.git.reinette.chatre@intel.com
2022-07-07 10:13:03 -07:00
Ard Biesheuvel
0f5b2c69a4 efi: vars: Remove deprecated 'efivars' sysfs interface
Commit 5d9db88376 ("efi: Add support for a UEFI variable filesystem")
dated Oct 5, 2012, introduced a new efivarfs pseudo-filesystem to
replace the efivars sysfs interface that was used up to that point to
expose EFI variables to user space.

The main problem with the sysfs interface was that it only supported up
to 1024 bytes of payload per file, whereas the underlying variables
themselves are only bounded by a platform specific per-variable and
global limit that is typically much higher than 1024 bytes.

The deprecated sysfs interface is only enabled on x86 and Itanium, other
EFI enabled architectures only support the efivarfs pseudo-filesystem.

So let's finally rip off the band aid, and drop the old interface
entirely. This will make it easier to refactor and clean up the
underlying infrastructure that is shared between efivars, efivarfs and
efi-pstore, and is long overdue for a makeover.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24 20:40:19 +02:00
Dongli Zhang
04c14e8e38 x86/swiotlb: fix param usage in boot-options.rst
Fix the usage of swiotlb param in kernel doc.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-06-22 12:42:08 +02:00
Linus Torvalds
88a618920e Merge tag 'docs-5.19' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It was a moderately busy cycle for documentation; highlights include:

   - After a long period of inactivity, the Japanese translations are
     seeing some much-needed maintenance and updating.

   - Reworked IOMMU documentation

   - Some new documentation for static-analysis tools

   - A new overall structure for the memory-management documentation.
     This is an LSFMM outcome that, it is hoped, will help encourage
     developers to fill in the many gaps. Optimism is eternal...but
     hopefully it will work.

   - More Chinese translations.

  Plus the usual typo fixes, updates, etc"

* tag 'docs-5.19' of git://git.lwn.net/linux: (70 commits)
  docs: pdfdocs: Add space for chapter counts >= 100 in TOC
  docs/zh_CN: Add dev-tools/gdb-kernel-debugging.rst Chinese translation
  input: Docs: correct ntrig.rst typo
  input: Docs: correct atarikbd.rst typos
  MAINTAINERS: Become the docs/zh_CN maintainer
  docs/zh_CN: fix devicetree usage-model translation
  mm,doc: Add new documentation structure
  Documentation: drop more IDE boot options and ide-cd.rst
  Documentation/process: use scripts/get_maintainer.pl on patches
  MAINTAINERS: Add entry for DOCUMENTATION/JAPANESE
  docs/trans/ja_JP/howto: Don't mention specific kernel versions
  docs/ja_JP/SubmittingPatches: Request summaries for commit references
  docs/ja_JP/SubmittingPatches: Add Suggested-by as a standard signature
  docs/ja_JP/SubmittingPatches: Randy has moved
  docs/ja_JP/SubmittingPatches: Suggest the use of scripts/get_maintainer.pl
  docs/ja_JP/SubmittingPatches: Update GregKH links
  Documentation/sysctl: document max_rcu_stall_to_panic
  Documentation: add missing angle bracket in cgroup-v2 doc
  Documentation: dev-tools: use literal block instead of code-block
  docs/zh_CN: add vm numa translation
  ...
2022-05-25 11:17:41 -07:00
Linus Torvalds
8443516da6 Merge tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Hans de Goede:
 "This includes some small changes to kernel/stop_machine.c and arch/x86
  which are deps of the new Intel IFS support.

  Highlights:

   - New drivers:
       - Intel "In Field Scan" (IFS) support
       - Winmate FM07/FM07P buttons
       - Mellanox SN2201 support

   -  AMD PMC driver enhancements

   -  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (54 commits)
  platform/x86/intel/ifs: Add CPU_SUP_INTEL dependency
  platform/x86: intel_cht_int33fe: Set driver data
  platform/x86: intel-hid: fix _DSM function index handling
  platform/x86: toshiba_acpi: use kobj_to_dev()
  platform/x86: samsung-laptop: use kobj_to_dev()
  platform/x86: gigabyte-wmi: Add support for Z490 AORUS ELITE AC and X570 AORUS ELITE WIFI
  tools/power/x86/intel-speed-select: Fix warning for perf_cap.cpu
  tools/power/x86/intel-speed-select: Display error on turbo mode disabled
  Documentation: In-Field Scan
  platform/x86/intel/ifs: add ABI documentation for IFS
  trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations
  platform/x86/intel/ifs: Add IFS sysfs interface
  platform/x86/intel/ifs: Add scan test support
  platform/x86/intel/ifs: Authenticate and copy to secured memory
  platform/x86/intel/ifs: Check IFS Image sanity
  platform/x86/intel/ifs: Read IFS firmware image
  platform/x86/intel/ifs: Add stub driver for In-Field Scan
  stop_machine: Add stop_core_cpuslocked() for per-core operations
  x86/msr-index: Define INTEGRITY_CAPABILITIES MSR
  x86/microcode/intel: Expose collect_cpu_info_early() for IFS
  ...
2022-05-23 20:38:39 -07:00
Linus Torvalds
c5a3d3c01e Merge tag 'x86_cpu_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CPU feature updates from Borislav Petkov:

 - Remove a bunch of chicken bit options to turn off CPU features which
   are not really needed anymore

 - Misc fixes and cleanups

* tag 'x86_cpu_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation: Add missing prototype for unpriv_ebpf_notify()
  x86/pm: Fix false positive kmemleak report in msr_build_context()
  x86/speculation/srbds: Do not try to turn mitigation off when not supported
  x86/cpu: Remove "noclflush"
  x86/cpu: Remove "noexec"
  x86/cpu: Remove "nosmep"
  x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"
  x86/cpu: Remove "nosep"
  x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid=
2022-05-23 18:01:31 -07:00
Linus Torvalds
3a755ebcc2 Merge tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull Intel TDX support from Borislav Petkov:
 "Intel Trust Domain Extensions (TDX) support.

  This is the Intel version of a confidential computing solution called
  Trust Domain Extensions (TDX). This series adds support to run the
  kernel as part of a TDX guest. It provides similar guest protections
  to AMD's SEV-SNP like guest memory and register state encryption,
  memory integrity protection and a lot more.

  Design-wise, it differs from AMD's solution considerably: it uses a
  software module which runs in a special CPU mode called (Secure
  Arbitration Mode) SEAM. As the name suggests, this module serves as
  sort of an arbiter which the confidential guest calls for services it
  needs during its lifetime.

  Just like AMD's SNP set, this series reworks and streamlines certain
  parts of x86 arch code so that this feature can be properly
  accomodated"

* tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  x86/tdx: Fix RETs in TDX asm
  x86/tdx: Annotate a noreturn function
  x86/mm: Fix spacing within memory encryption features message
  x86/kaslr: Fix build warning in KASLR code in boot stub
  Documentation/x86: Document TDX kernel architecture
  ACPICA: Avoid cache flush inside virtual machines
  x86/tdx/ioapic: Add shared bit for IOAPIC base address
  x86/mm: Make DMA memory shared for TD guest
  x86/mm/cpa: Add support for TDX shared memory
  x86/tdx: Make pages shared in ioremap()
  x86/topology: Disable CPU online/offline control for TDX guests
  x86/boot: Avoid #VE during boot for TDX platforms
  x86/boot: Set CR0.NE early and keep it set during the boot
  x86/acpi/x86/boot: Add multiprocessor wake-up support
  x86/boot: Add a trampoline for booting APs via firmware handoff
  x86/tdx: Wire up KVM hypercalls
  x86/tdx: Port I/O: Add early boot support
  x86/tdx: Port I/O: Add runtime hypercalls
  x86/boot: Port I/O: Add decompression-time support for TDX
  x86/boot: Port I/O: Allow to hook up alternative helpers
  ...
2022-05-23 17:51:12 -07:00
Tony Luck
34604d2891 Documentation: In-Field Scan
Add documentation for In-Field Scan (IFS). This documentation
describes the basics of IFS, the loading IFS image, chunk
authentication, running scan and how to check result via sysfs.

The CORE_CAPABILITIES MSR enumerates whether IFS is supported.

The full  github location for distributing the IFS images is
still being decided. So just a placeholder included for now
in the documentation.

Future CPUs will support more than one type of test. Plan for
that now by using a "_0" suffix on the ABI directory names.
Additional test types will use "_1", etc.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-13-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Alex Deucher
2a8d78d566 Documentation: x86: rework IOMMU documentation
Add preliminary documentation for AMD IOMMU and combine
with the existing Intel IOMMU documentation and clean
up and modernize some of the existing documentation to
align with the current state of the kernel.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20220422192656.624920-1-alexander.deucher@amd.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-04-28 07:59:45 -06:00
Kuppuswamy Sathyanarayanan
b9c7ba5877 Documentation/x86: Document TDX kernel architecture
Document the TDX guest architecture details like #VE support,
shared memory, etc.

[ dhansen: made some wording changes, including removing
	   all the plural "#VE's" and "#VEs". ]

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220405232939.73860-31-kirill.shutemov@linux.intel.com
2022-04-08 06:57:09 -07:00
Michael Roth
ba37a1438a x86/sev: Add a sev= cmdline option
For debugging purposes it is very useful to have a way to see the full
contents of the SNP CPUID table provided to a guest. Add an sev=debug
kernel command-line option to do so.

Also introduce some infrastructure so that additional options can be
specified via sev=option1[,option2] over time in a consistent manner.

  [ bp: Massage, simplify string parsing. ]

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-41-brijesh.singh@amd.com
2022-04-07 16:47:12 +02:00
Michael Roth
8c9c509baf x86/boot: Add a pointer to Confidential Computing blob in bootparams
The previously defined Confidential Computing blob is provided to the
kernel via a setup_data structure or EFI config table entry. Currently,
these are both checked for by boot/compressed kernel to access the CPUID
table address within it for use with SEV-SNP CPUID enforcement.

To also enable that enforcement for the run-time kernel, similar
access to the CPUID table is needed early on while it's still using
the identity-mapped page table set up by boot/compressed, where global
pointers need to be accessed via fixup_pointer().

This isn't much of an issue for accessing setup_data, and the EFI config
table helper code currently used in boot/compressed *could* be used in
this case as well since they both rely on identity-mapping. However, it
has some reliance on EFI helpers/string constants that would need to be
accessed via fixup_pointer(), and fixing it up while making it shareable
between boot/compressed and run-time kernel is fragile and introduces a
good bit of ugliness.

Instead, add a boot_params->cc_blob_address pointer that the
boot/compressed kernel can initialize so that the run-time kernel can
access the CC blob from there instead of re-scanning the EFI config
table.

Also document these in Documentation/x86/zero-page.rst. While there,
add missing documentation for the acpi_rsdp_addr field, which serves a
similar purpose in providing the run-time kernel a pointer to the ACPI
RSDP table so that it does not need to [re-]scan the EFI configuration
table.

  [ bp: Fix typos, massage commit message. ]

Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-34-brijesh.singh@amd.com
2022-04-07 16:47:11 +02:00
Chin En Lin
d4cd2389d0 Documentation: x86: Fix obsolete name of page fault handler
Since commit 91eeafea1e ("x86/entry: Switch page fault exception to
IDTENTRY_RAW"), the function name of the page fault handler is out of date.
And because of commit aa37c51b94 ("x86/mm: Break out user address space
handling"), the description of search_exception_table is not correct
anymore. It may mislead the user who wants to use the documentation to
figure out the page fault handler.

Also, fix typo and add the parentheses after function and macro name.

Signed-off-by: Chin En Lin <shiyn.lin@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-04-05 10:28:36 -06:00
Borislav Petkov
76ea0025a2 x86/cpu: Remove "noexec"
It doesn't make any sense to disable non-executable mappings -
security-wise or else.

So rip out that switch and move the remaining code into setup.c and
delete setup_nx.c

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-6-bp@alien8.de
2022-04-04 10:17:03 +02:00
Borislav Petkov
385d2ae0a1 x86/cpu: Remove "nosmep"
There should be no need to disable SMEP anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-5-bp@alien8.de
2022-04-04 10:17:00 +02:00
Borislav Petkov
dbae0a934f x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"
Those were added as part of the SMAP enablement but SMAP is currently
an integral part of kernel proper and there's no need to disable it
anymore.

Rip out that functionality. Leave --uaccess default on for objtool as
this is what objtool should do by default anyway.

If still needed - clearcpuid=smap.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-4-bp@alien8.de
2022-04-04 10:16:57 +02:00
Linus Torvalds
636f64db07 Merge tag 'ras_core_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:

 - More noinstr fixes

 - Add an erratum workaround for Intel CPUs which, in certain
   circumstances, end up consuming an unrelated uncorrectable memory
   error when using fast string copy insns

 - Remove the MCE tolerance level control as it is not really needed or
   used anymore

* tag 'ras_core_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Remove the tolerance level control
  x86/mce: Work around an erratum on fast string copy instructions
  x86/mce: Use arch atomic and bit helpers
2022-03-25 12:34:53 -07:00
Linus Torvalds
1464677662 Merge tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Hans de Goede:
  "New drivers:
    - AMD Host System Management Port (HSMP)
    - Intel Software Defined Silicon

  Removed drivers (functionality folded into other drivers):
    - intel_cht_int33fe_microb
    - surface3_button

  amd-pmc:
    - s2idle bug-fixes
    - Support for AMD Spill to DRAM STB feature

  hp-wmi:
    - Fix SW_TABLET_MODE detection method (and other fixes)
    - Support omen thermal profile policy v1

  serial-multi-instantiate:
    - Add SPI device support
    - Add support for CS35L41 amplifiers used in new laptops

  think-lmi:
    - syfs-class-firmware-attributes Certificate authentication support

  thinkpad_acpi:
    - Fixes + quirks
    - Add platform_profile support on AMD based ThinkPads

  x86-android-tablets:
    - Improve Asus ME176C / TF103C support
    - Support Nextbook Ares 8, Lenovo Tab 2 830 and 1050 tablets

  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (60 commits)
  platform/x86: think-lmi: Certificate authentication support
  Documentation: syfs-class-firmware-attributes: Lenovo Certificate support
  platform/x86: amd-pmc: Only report STB errors when STB enabled
  platform/x86: amd-pmc: Drop CPU QoS workaround
  platform/x86: amd-pmc: Output error codes in messages
  platform/x86: amd-pmc: Move to later in the suspend process
  ACPI / x86: Add support for LPS0 callback handler
  platform/x86: thinkpad_acpi: consistently check fan_get_status return.
  platform/x86: hp-wmi: support omen thermal profile policy v1
  platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated
  platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls
  platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method
  platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)
  platform/x86: amd-pmc: Validate entry into the deepest state on resume
  platform/x86: thinkpad_acpi: Don't use test_bit on an integer
  platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable
  platform/x86: thinkpad_acpi: clean up dytc profile convert
  platform/x86: x86-android-tablets: Depend on EFI and SPI
  platform/x86: amd-pmc: uninitialized variable in amd_pmc_s2d_init()
  platform/x86: intel-uncore-freq: fix uncore_freq_common_init() error codes
  ...
2022-03-25 12:14:39 -07:00
Linus Torvalds
f648372dfe Merge tag 'thermal-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull thermal control updates from Rafael Wysocki:
 "As far as new functionality is concerned, there is a new thermal
  driver for the Intel Hardware Feedback Interface (HFI) along with some
  intel-speed-select utility changes to support it. There are also new
  DT compatible strings for a couple of platforms, and thermal zones on
  some platforms will be registered as HWmon sensors now.

  Apart from the above, some drivers are updated (fixes mostly) and
  there is a new piece of documentation for the Intel DPTF (Dynamic
  Power and Thermal Framework) sysfs interface.

  Specifics:

   - Add a new thermal driver for the Intel Hardware Feedback Interface
     (HFI) including the HFI initialization, HFI notification interrupt
     handling and sending CPU capabilities change messages to user space
     via the thermal netlink interface (Ricardo Neri, Srinivas
     Pandruvada, Nathan Chancellor, Randy Dunlap).

   - Extend the intel-speed-select utility to handle out-of-band CPU
     configuration changes and add support for the CPU capabilities
     change messages sent over the thermal netlink interface by the new
     HFI thermal driver to it (Srinivas Pandruvada).

   - Convert the DT bindings to yaml format for the Exynos platform and
     fix and update the MAINTAINERS file for this driver (Krzysztof
     Kozlowski).

   - Register the thermal zones as HWmon sensors for the QCom's Tsens
     driver and TI thermal platforms (Dmitry Baryshkov, Romain Naour).

   - Add the msm8953 compatible documentation in the bindings (Luca
     Weiss).

   - Add the sm8150 platform support to the QCom LMh driver's DT binding
     (Thara Gopinath).

   - Check the command result from the IPC command to the BPMP in the
     Tegra driver (Mikko Perttunen).

   - Silence the error for normal configuration where the interrupt is
     optionnal in the Broadcom thermal driver (Florian Fainelli).

   - Remove remaining dead code from the TI thermal driver (Yue
     Haibing).

   - Don't use bitmap_weight() in end_power_clamp() in the powerclamp
     driver (Yury Norov).

   - Update the OS policy capabilities handshake in the int340x thermal
     driver (Srinivas Pandruvada).

   - Increase the policies bitmap size in int340x (Srinivas Pandruvada).

   - Replace acpi_bus_get_device() with acpi_fetch_acpi_dev() in the
     int340x thermal driver (Rafael Wysocki).

   - Check for NULL after calling kmemdup() in int340x (Jiasheng Jiang).

   - Add Intel Dynamic Power and Thermal Framework (DPTF) kernel
     interface documentation (Srinivas Pandruvada).

   - Fix bullet list warning in the thermal documentation (Randy
     Dunlap)"

* tag 'thermal-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (30 commits)
  thermal: int340x: Update OS policy capability handshake
  thermal: int340x: Increase bitmap size
  Documentation: thermal: DPTF Documentation
  MAINTAINERS: thermal: samsung: update Krzysztof Kozlowski's email
  thermal/drivers/ti-soc-thermal: Remove unused function ti_thermal_get_temp()
  thermal/drivers/brcmstb_thermal: Interrupt is optional
  thermal: tegra-bpmp: Handle errors in BPMP response
  drivers/thermal/ti-soc-thermal: Add hwmon support
  dt-bindings: thermal: tsens: Add msm8953 compatible
  dt-bindings: thermal: Add sm8150 compatible string for LMh
  thermal/drivers/qcom/lmh: Add support for sm8150
  thermal/drivers/tsens: register thermal zones as hwmon sensors
  MAINTAINERS: thermal: samsung: Drop obsolete properties
  dt-bindings: thermal: samsung: Convert to dtschema
  tools/power/x86/intel-speed-select: v1.12 release
  tools/power/x86/intel-speed-select: HFI support
  tools/power/x86/intel-speed-select: OOB daemon mode
  thermal: intel: hfi: INTEL_HFI_THERMAL depends on NET
  thermal: netlink: Fix parameter type of thermal_genl_cpu_capability_event() stub
  thermal: Replace acpi_bus_get_device()
  ...
2022-03-21 14:35:11 -07:00
Naveen Krishna Chatradhi
402576d980 Documentation: Add x86/amd_hsmp driver
This documentation for amd_hsmp driver explains how to use the
device interface.

Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20220222050501.18789-2-nchatrad@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-03-02 11:42:36 +01:00
Borislav Petkov
7f1b8e0d63 x86/mce: Remove the tolerance level control
This is pretty much unused and not really useful. What is more, all
relevant MCA hardware has recoverable machine checks support so there's
no real need to tweak MCA tolerance levels in order to *maybe* extend
machine lifetime.

So rip it out.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/YcDq8PxvKtTENl/e@zn.tnic
2022-02-23 11:09:25 +01:00
Fenghua Yu
83aa52ffed Documentation/x86: Update documentation for SVA (Shared Virtual Addressing)
Adjust the documentation to the new way how a PASID is being allocated,
freed and fixed up.

Based on a patch by Ashok Raj <ashok.raj@intel.com>

  [ bp: Massage commit message, fix htmldocs build warning ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-12-fenghua.yu@intel.com
2022-02-15 11:31:43 +01:00
Ricardo Neri
4a960e8941 x86/Documentation: Describe the Intel Hardware Feedback Interface
Start a documentation file to describe the purpose and operation of Intel's
Hardware Feedback Interface. Describe how this interface is used in Linux
to relay performance and energy efficiency updates to userspace.

Reviewed-by: Len Brown <len.brown@intel.com>
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-02-03 19:50:48 +01:00
Reinette Chatre
379e4de9e1 x86/sgx: Fix minor documentation issues
The SGX documentation has a few repeated or one-off issues:

 * Remove capitalization from regular words in the middle of a sentence.
 * Remove punctuation found in the middle of a sentence.
 * Fix name of SGX daemon to consistently be ksgxd.
 * Fix typo of SGX instruction: ENIT -> EINIT

[ dhansen: tweaked subject and changelog ]

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/ab99a87368eef69e3fb96f073368becff3eff874.1635529506.git.reinette.chatre@intel.com
2021-11-17 06:36:09 -08:00
Linus Torvalds
1654e95ee3 Merge tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - Add the model number of a new, Raptor Lake CPU, to intel-family.h

 - Do not log spurious corrected MCEs on SKL too, due to an erratum

 - Clarify the path of paravirt ops patches upstream

 - Add an optimization to avoid writing out AMX components to sigframes
   when former are in init state

* tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add Raptor Lake to Intel family
  x86/mce: Add errata workaround for Skylake SKX37
  MAINTAINERS: Add some information to PARAVIRT_OPS entry
  x86/fpu: Optimize out sigframe xfeatures when in init state
2021-11-14 09:29:03 -08:00
Linus Torvalds
95faf6ba65 Merge tag 'driver-core-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 5.16-rc1.

  All of these have been in linux-next for a while now with no reported
  problems.

  Included in here are:

   - big update and cleanup of the sysfs abi documentation files and
     scripts from Mauro. We are almost at the place where we can
     properly check that the running kernel's sysfs abi is documented
     fully.

   - firmware loader updates

   - dyndbg updates

   - kernfs cleanups and fixes from Christoph

   - device property updates

   - component fix

   - other minor driver core cleanups and fixes"

* tag 'driver-core-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (122 commits)
  device property: Drop redundant NULL checks
  x86/build: Tuck away built-in firmware under FW_LOADER
  vmlinux.lds.h: wrap built-in firmware support under FW_LOADER
  firmware_loader: move struct builtin_fw to the only place used
  x86/microcode: Use the firmware_loader built-in API
  firmware_loader: remove old DECLARE_BUILTIN_FIRMWARE()
  firmware_loader: formalize built-in firmware API
  component: do not leave master devres group open after bind
  dyndbg: refine verbosity 1-4 summary-detail
  gpiolib: acpi: Replace custom code with device_match_acpi_handle()
  i2c: acpi: Replace custom function with device_match_acpi_handle()
  driver core: Provide device_match_acpi_handle() helper
  dyndbg: fix spurious vNpr_info change
  dyndbg: no vpr-info on empty queries
  dyndbg: vpr-info on remove-module complete, not starting
  device property: Add missed header in fwnode.h
  Documentation: dyndbg: Improve cli param examples
  dyndbg: Remove support for ddebug_query param
  dyndbg: make dyndbg a known cli param
  dyndbg: show module in vpr-info in dd-exec-queries
  ...
2021-11-04 08:32:38 -07:00
Dave Hansen
30d02551ba x86/fpu: Optimize out sigframe xfeatures when in init state
tl;dr: AMX state is ~8k.  Signal frames can have space for this
~8k and each signal entry writes out all 8k even if it is zeros.
Skip writing zeros for AMX to speed up signal delivery by about
4% overall when AMX is in its init state.

This is a user-visible change to the sigframe ABI.

== Hardware XSAVE Background ==

XSAVE state components may be tracked by the processor as being
in their initial configuration.  Software can detect which
features are in this configuration by looking at the XSTATE_BV
field in an XSAVE buffer or with the XGETBV(1) instruction.

Both the XSAVE and XSAVEOPT instructions enumerate features s
being in the initial configuration via the XSTATE_BV field in the
XSAVE header,  However, XSAVEOPT declines to actually write
features in their initial configuration to the buffer.  XSAVE
writes the feature unconditionally, regardless of whether it is
in the initial configuration or not.

Basically, XSAVE users never need to inspect XSTATE_BV to
determine if the feature has been written to the buffer.
XSAVEOPT users *do* need to inspect XSTATE_BV.  They might also
need to clear out the buffer if they want to make an isolated
change to the state, like modifying one register.

== Software Signal / XSAVE Background ==

Signal frames have historically been written with XSAVE itself.
Each state is written in its entirety, regardless of being in its
initial configuration.

In other words, the signal frame ABI uses the XSAVE behavior, not
the XSAVEOPT behavior.

== Problem ==

This means that any application which has acquired permission to
use AMX via ARCH_REQ_XCOMP_PERM will write 8k of state to the
signal frame.  This 8k write will occur even when AMX was in its
initial configuration and software *knows* this because of
XSTATE_BV.

This problem also exists to a lesser degree with AVX-512 and its
2k of state.  However, AVX-512 use does not require
ARCH_REQ_XCOMP_PERM and is more likely to have existing users
which would be impacted by any change in behavior.

== Solution ==

Stop writing out AMX xfeatures which are in their initial state
to the signal frame.  This effectively makes the signal frame
XSAVE buffer look as if it were written with a combination of
XSAVEOPT and XSAVE behavior.  Userspace which handles XSAVEOPT-
style buffers should be able to handle this naturally.

For now, include only the AMX xfeatures: XTILE and XTILEDATA in
this new behavior.  These require new ABI to use anyway, which
makes their users very unlikely to be broken.  This XSAVEOPT-like
behavior should be expected for all future dynamic xfeatures.  It
may also be extended to legacy features like AVX-512 in the
future.

Only attempt this optimization on systems with dynamic features.
Disable dynamic feature support (XFD) if XGETBV1 is unavailable
by adding a CPUID dependency.

This has been measured to reduce the *overall* cycle cost of
signal delivery by about 4%.

Fixes: 2308ee57d9 ("x86/fpu/amx: Enable the AMX feature in 64-bit mode")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: "Chang S. Bae" <chang.seok.bae@intel.com>
Link: https://lore.kernel.org/r/20211102224750.FA412E26@davehans-spike.ostc.intel.com
2021-11-03 22:42:35 +01:00
Linus Torvalds
624ad333d4 Merge tag 'docs-5.16' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "This is a relatively unexciting cycle for documentation.

   - Some small scripts/kerneldoc fixes

   - More Chinese translation work, but at a much reduced rate.

   - The tip-tree maintainer's handbook

  ...plus the usual array of build fixes, typo fixes, etc"

* tag 'docs-5.16' of git://git.lwn.net/linux: (53 commits)
  kernel-doc: support DECLARE_PHY_INTERFACE_MASK()
  docs/zh_CN: add core-api xarray translation
  docs/zh_CN: add core-api assoc_array translation
  speakup: Fix typo in documentation "boo" -> "boot"
  docs: submitting-patches: make section about the Link: tag more explicit
  docs: deprecated.rst: Clarify open-coded arithmetic with literals
  scripts: documentation-file-ref-check: fix bpf selftests path
  scripts: documentation-file-ref-check: ignore hidden files
  coding-style.rst: trivial: fix location of driver model macros
  docs: f2fs: fix text alignment
  docs/zh_CN add PCI pci.rst translation
  docs/zh_CN add PCI index.rst translation
  docs: translations: zh_CN: memory-hotplug.rst: fix a typo
  docs: translations: zn_CN: irq-affinity.rst: add a missing extension
  block: add documentation for inflight
  scripts: kernel-doc: Ignore __alloc_size() attribute
  docs: pdfdocs: Adjust \headheight for fancyhdr
  docs: UML: user_mode_linux_howto_v2 edits
  docs: use the lore redirector everywhere
  docs: proc.rst: mountinfo: align columns
  ...
2021-11-02 22:11:39 -07:00
Linus Torvalds
879dbe9ffe Merge tag 'x86_sgx_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Borislav Petkov:
 "Add a SGX_IOC_VEPC_REMOVE ioctl to the /dev/sgx_vepc virt interface
  with which EPC pages can be put back into their uninitialized state
  without having to reopen /dev/sgx_vepc, which could not be possible
  anymore after startup due to security policies"

* tag 'x86_sgx_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx/virt: implement SGX_IOC_VEPC_REMOVE ioctl
  x86/sgx/virt: extract sgx_vepc_remove_page
2021-11-01 15:54:07 -07:00
Chang S. Bae
d7a9590f60 Documentation/x86: Add documentation for using dynamic XSTATE features
Explain how dynamic XSTATE features can be enabled via the
architecture-specific prctl() along with dynamic sigframe size and
first use trap handling.

Fix:

Documentation/x86/xstate.rst:15: WARNING: Title underline too short.

as reported by Stephen Rothwell <sfr@canb.auug.org.au>

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211026091157.16711-1-chang.seok.bae@intel.com
2021-10-28 14:54:58 +02:00
Paolo Bonzini
ae095b16fc x86/sgx/virt: implement SGX_IOC_VEPC_REMOVE ioctl
For bare-metal SGX on real hardware, the hardware provides guarantees
SGX state at reboot.  For instance, all pages start out uninitialized.
The vepc driver provides a similar guarantee today for freshly-opened
vepc instances, but guests such as Windows expect all pages to be in
uninitialized state on startup, including after every guest reboot.

Some userspace implementations of virtual SGX would rather avoid having
to close and reopen the /dev/sgx_vepc file descriptor and re-mmap the
virtual EPC.  For example, they could sandbox themselves after the guest
starts and forbid further calls to open(), in order to mitigate exploits
from untrusted guests.

Therefore, add a ioctl that does this with EREMOVE.  Userspace can
invoke the ioctl to bring its vEPC pages back to uninitialized state.
There is a possibility that some pages fail to be removed if they are
SECS pages, and the child and SECS pages could be in separate vEPC
regions.  Therefore, the ioctl returns the number of EREMOVE failures,
telling userspace to try the ioctl again after it's done with all
vEPC regions.  A more verbose description of the correct usage and
the possible error conditions is documented in sgx.rst.

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20211021201155.1523989-3-pbonzini@redhat.com
2021-10-22 08:32:12 -07:00
Thorsten Leemhuis
a9d85efb25 docs: use the lore redirector everywhere
Change all links from using the lkml redirector to the lore redirector,
as the kernel.org admin recently indicated: we shouldn't be using
lkml.kernel.org anymore because the domain can create confusion, as it
indicates it is only valid for messages sent to the LKML; the convention
has been to use https://lore.kernel.org/r/msgid for this reason.

In this process also change three links from using http to https.

Link: https://lore.kernel.org/r/20211006170025.qw3glxvocczfuhar@meerkat.local
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Hu Haowen <src.res@email.cn>
CC: Alex Shi <alexs@kernel.org>
CC: Federico Vaga <federico.vaga@vaga.pv.it>
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Link: https://lore.kernel.org/r/5bb55bac6ba10fafab19bf2b21572dd0e2f8cea2.1633593385.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-10-12 13:58:19 -06:00
Mauro Carvalho Chehab
edfc8730ba ABI: sysfs-mce: add a new ABI file
Reduce the gap of missing ABIs for Intel servers with MCE
by adding a new ABI file.

The contents of this file comes from:
	Documentation/x86/x86_64/machinecheck.rst

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/801a26985e32589eb78ba4b728d3e19fdea18f04.1632994837.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-05 16:24:15 +02:00
Linus Torvalds
0f4b9289ba Merge tag 'docs-5.15-2' of git://git.lwn.net/linux
Pull more documentation updates from Jonathan Corbet:
 "Another collection of documentation patches, mostly fixes but also
  includes another set of traditional Chinese translations"

* tag 'docs-5.15-2' of git://git.lwn.net/linux:
  docs: pdfdocs: Fix typo in CJK-language specific font settings
  docs: kernel-hacking: Remove inappropriate text
  docs/zh_TW: add translations for zh_TW/filesystems
  docs/zh_TW: add translations for zh_TW/cpu-freq
  docs/zh_TW: add translations for zh_TW/arm64
  docs/zh_CN: Modify the translator tag and fix the wrong word
  Documentation/features/vm: correct huge-vmap APIs
  Documentation: block: blk-mq: Fix small typo in multi-queue docs
  Documentation: in_irq() cleanup
  Documentation: arm: marvell: Add 88F6825 model into list
  Documentation/process/maintainer-pgp-guide: Replace broken link to PGP path finder
  Documentation: locking: fix references
  Documentation: Update details of The Linux Kernel Module Programming Guide
  docs: x86: Remove obsolete information about x86_64 vmalloc() faulting
  Documentation/process/applying-patches: Activate linux-next man hyperlink
2021-09-08 16:28:14 -07:00
Peilin Ye
251a7b3edc docs: x86: Remove obsolete information about x86_64 vmalloc() faulting
x86_64 vmalloc() mappings are no longer "synchronized" among page tables
via faulting since commit 6eb82f9940 ("x86/mm: Pre-allocate P4D/PUD
pages for vmalloc area"), since the corresponding P4D or PUD pages are
now preallocated at boot, by preallocate_vmalloc_pages().  Drop the
"lazily synchronized" description for less confusion.

While this file is x86_64-specific, it is worth noting that things are
different for x86_32, where vmalloc()-related changes to `init_mm.pgd` are
synchronized to all page tables in the system during runtime, via
arch_sync_kernel_mappings().  Unfortunately, this synchronization is
subject to race condition, which is further handled via faulting, see
vmalloc_fault().  See commit 4819e15f74 ("x86/mm/32: Bring back vmalloc
faulting on x86_32") for more details.

Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210818220123.2623-1-yepeilin.cs@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-08-20 11:14:11 -06:00
Paul Gortmaker
12febc1818 x86/reboot: Document how to override DMI platform quirks
commit 5955633e91 ("x86/reboot: Skip DMI checks if reboot set by user")
made it so that it's not required to recompile the kernel in order to
bypass broken reboot quirks compiled into an image:

 * This variable is used privately to keep track of whether or not
 * reboot_type is still set to its default value (i.e., reboot= hasn't
 * been set on the command line).  This is needed so that we can
 * suppress DMI scanning for reboot quirks.  Without it, it's
 * impossible to override a faulty reboot quirk without recompiling.

However, at the time it was not eally documented outside the source code,
and so this information isn't really available to the average user out
there.

The change is a little white lie and invented "reboot=default" since it is
easy to remember, and documents well.  The truth is that any random string
that is *not* a currently accepted string will work.

Since that doesn't document well for non-coders, and since it's unknown
what the future additions might be, lay claim on "default" since that is
exactly what it achieves.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210530162447.996461-3-paul.gortmaker@windriver.com
2021-08-12 12:06:58 +02:00
Paul Gortmaker
162a5284fa x86/reboot: Document the "reboot=pci" option
It is mentioned in the top level non-arch specific file but it was
overlooked here for x86.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210530162447.996461-2-paul.gortmaker@windriver.com
2021-08-12 12:06:58 +02:00
Linus Torvalds
1423e2660c Merge tag 'x86-fpu-2021-07-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Thomas Gleixner:
 "Fixes and improvements for FPU handling on x86:

   - Prevent sigaltstack out of bounds writes.

     The kernel unconditionally writes the FPU state to the alternate
     stack without checking whether the stack is large enough to
     accomodate it.

     Check the alternate stack size before doing so and in case it's too
     small force a SIGSEGV instead of silently corrupting user space
     data.

   - MINSIGSTKZ and SIGSTKSZ are constants in signal.h and have never
     been updated despite the fact that the FPU state which is stored on
     the signal stack has grown over time which causes trouble in the
     field when AVX512 is available on a CPU. The kernel does not expose
     the minimum requirements for the alternate stack size depending on
     the available and enabled CPU features.

     ARM already added an aux vector AT_MINSIGSTKSZ for the same reason.
     Add it to x86 as well.

   - A major cleanup of the x86 FPU code. The recent discoveries of
     XSTATE related issues unearthed quite some inconsistencies,
     duplicated code and other issues.

     The fine granular overhaul addresses this, makes the code more
     robust and maintainable, which allows to integrate upcoming XSTATE
     related features in sane ways"

* tag 'x86-fpu-2021-07-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
  x86/fpu/xstate: Clear xstate header in copy_xstate_to_uabi_buf() again
  x86/fpu/signal: Let xrstor handle the features to init
  x86/fpu/signal: Handle #PF in the direct restore path
  x86/fpu: Return proper error codes from user access functions
  x86/fpu/signal: Split out the direct restore code
  x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing()
  x86/fpu/signal: Sanitize the xstate check on sigframe
  x86/fpu/signal: Remove the legacy alignment check
  x86/fpu/signal: Move initial checks into fpu__restore_sig()
  x86/fpu: Mark init_fpstate __ro_after_init
  x86/pkru: Remove xstate fiddling from write_pkru()
  x86/fpu: Don't store PKRU in xstate in fpu_reset_fpstate()
  x86/fpu: Remove PKRU handling from switch_fpu_finish()
  x86/fpu: Mask PKRU from kernel XRSTOR[S] operations
  x86/fpu: Hook up PKRU into ptrace()
  x86/fpu: Add PKRU storage outside of task XSAVE buffer
  x86/fpu: Dont restore PKRU in fpregs_restore_userspace()
  x86/fpu: Rename xfeatures_mask_user() to xfeatures_mask_uabi()
  x86/fpu: Move FXSAVE_LEAK quirk info __copy_kernel_to_fpregs()
  x86/fpu: Rename __fpregs_load_activate() to fpregs_restore_userregs()
  ...
2021-07-07 11:12:01 -07:00
Linus Torvalds
233a806b00 Merge tag 'docs-5.14' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "This was a reasonably active cycle for documentation; this includes:

   - Some kernel-doc cleanups. That script is still regex onslaught from
     hell, but it has gotten a little better.

   - Improvements to the checkpatch docs, which are also used by the
     tool itself.

   - A major update to the pathname lookup documentation.

   - Elimination of :doc: markup, since our automarkup magic can create
     references from filenames without all the extra noise.

   - The flurry of Chinese translation activity continues.

  Plus, of course, the usual collection of updates, typo fixes, and
  warning fixes"

* tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits)
  docs: path-lookup: use bare function() rather than literals
  docs: path-lookup: update symlink description
  docs: path-lookup: update get_link() ->follow_link description
  docs: path-lookup: update WALK_GET, WALK_PUT desc
  docs: path-lookup: no get_link()
  docs: path-lookup: update i_op->put_link and cookie description
  docs: path-lookup: i_op->follow_link replaced with i_op->get_link
  docs: path-lookup: Add macro name to symlink limit description
  docs: path-lookup: remove filename_mountpoint
  docs: path-lookup: update do_last() part
  docs: path-lookup: update path_mountpoint() part
  docs: path-lookup: update path_to_nameidata() part
  docs: path-lookup: update follow_managed() part
  docs: Makefile: Use CONFIG_SHELL not SHELL
  docs: Take a little noise out of the build process
  docs: x86: avoid using ReST :doc:`foo` markup
  docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup
  docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup
  docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup
  docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup
  ...
2021-06-28 16:53:05 -07:00
Linus Torvalds
1b1cf8fe99 Merge tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 splitlock updates from Ingo Molnar:

 - Add the "ratelimit:N" parameter to the split_lock_detect= boot
   option, to rate-limit the generation of bus-lock exceptions.

   This is both easier on system resources and kinder to offending
   applications than the current policy of outright killing them.

 - Document the split-lock detection feature and its parameters.

* tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/x86: Add ratelimit in buslock.rst
  Documentation/admin-guide: Add bus lock ratelimit
  x86/bus_lock: Set rate limit for bus lock
  Documentation/x86: Add buslock.rst
2021-06-28 13:30:02 -07:00
Mauro Carvalho Chehab
0ffd643875 docs: x86: avoid using ReST :doc:foo markup
The :doc:`foo` tag is auto-generated via automarkup.py.
So, use the filename at the sources, instead of :doc:`foo`.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/17c68b5f1d72488431c77c1de9f13683fe9f536c.1623824363.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-17 13:24:39 -06:00
Hubert Jasudowicz
0e5a89dbb4 doc: Remove references to IBM Calgary
The Calgary IOMMU driver has been removed in

  90dc392fc4 ("x86: Remove the calgary IOMMU driver")

Clean up stale docs that refer to it.

Signed-off-by: Hubert Jasudowicz <hubert.jasudowicz@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1bd2b57dd1db53df09e520b8170ff61418805de4.1623274832.git.hubert.jasudowicz@gmail.com
2021-06-10 18:19:36 +02:00
Chang S. Bae
1c33bb0507 x86/elf: Support a new ELF aux vector AT_MINSIGSTKSZ
Historically, signal.h defines MINSIGSTKSZ (2KB) and SIGSTKSZ (8KB), for
use by all architectures with sigaltstack(2). Over time, the hardware state
size grew, but these constants did not evolve. Today, literal use of these
constants on several architectures may result in signal stack overflow, and
thus user data corruption.

A few years ago, the ARM team addressed this issue by establishing
getauxval(AT_MINSIGSTKSZ). This enables the kernel to supply a value
at runtime that is an appropriate replacement on current and future
hardware.

Add getauxval(AT_MINSIGSTKSZ) support to x86, analogous to the support
added for ARM in

  94b07c1f8c ("arm64: signal: Report signal frame size to userspace via auxv").

Also, include a documentation to describe x86-specific auxiliary vectors.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210518200320.17239-4-chang.seok.bae@intel.com
2021-05-19 12:18:45 +02:00
Fenghua Yu
d28397eaf4 Documentation/x86: Add ratelimit in buslock.rst
ratelimit is a new command line option for bus lock handling. Add proper
documentation.

[ tglx: Massaged documentation ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-5-fenghua.yu@intel.com
2021-05-18 16:39:31 +02:00
Fenghua Yu
1897907cca Documentation/x86: Add buslock.rst
Add buslock.rst to explain bus lock problem and how to detect and
handle it.

[ tglx: Included it into index.rst and added the missing include ... ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-2-fenghua.yu@intel.com
2021-05-18 16:39:31 +02:00
Brijesh Singh
059e5c321a x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG
The SYSCFG MSR continued being updated beyond the K8 family; drop the K8
name from it.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-4-brijesh.singh@amd.com
2021-05-10 07:51:38 +02:00