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2022-05-25Merge tag 'docs-5.19' of git://git.lwn.net/linuxLinus Torvalds4-126/+165
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 ...
2022-05-24Merge tag 'platform-drivers-x86-v5.19-1' of ↵Linus Torvalds2-0/+3
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 ...
2022-05-24Merge tag 'x86_cpu_for_v5.19_rc1' of ↵Linus Torvalds2-12/+2
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=
2022-05-24Merge tag 'x86_tdx_for_v5.19_rc1' of ↵Linus Torvalds2-0/+219
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 ...
2022-05-12Documentation: In-Field ScanTony Luck2-0/+3
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>
2022-04-28Documentation: x86: rework IOMMU documentationAlex Deucher3-116/+152
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>
2022-04-08Documentation/x86: Document TDX kernel architectureKuppuswamy Sathyanarayanan2-0/+219
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
2022-04-07x86/sev: Add a sev= cmdline optionMichael Roth1-0/+14
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
2022-04-07x86/boot: Add a pointer to Confidential Computing blob in bootparamsMichael Roth1-0/+2
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
2022-04-05Documentation: x86: Fix obsolete name of page fault handlerChin En Lin1-10/+13
Since commit 91eeafea1e4b ("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 aa37c51b9421 ("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>
2022-04-04x86/cpu: Remove "noexec"Borislav Petkov1-9/+0
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
2022-04-04x86/cpu: Remove "nosmep"Borislav Petkov1-2/+2
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
2022-04-04x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"Borislav Petkov1-3/+2
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
2022-03-25Merge tag 'ras_core_for_v5.18_rc1' of ↵Linus Torvalds1-8/+1
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
2022-03-25Merge tag 'platform-drivers-x86-v5.18-1' of ↵Linus Torvalds2-0/+87
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 ...
2022-03-22Merge tag 'thermal-5.18-rc1' of ↵Linus Torvalds2-0/+73
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() ...
2022-03-02Documentation: Add x86/amd_hsmp driverNaveen Krishna Chatradhi2-0/+87
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>
2022-02-23x86/mce: Remove the tolerance level controlBorislav Petkov1-8/+1
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
2022-02-15Documentation/x86: Update documentation for SVA (Shared Virtual Addressing)Fenghua Yu1-12/+41
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
2022-02-03x86/Documentation: Describe the Intel Hardware Feedback InterfaceRicardo Neri2-0/+73
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>
2021-11-17x86/sgx: Fix minor documentation issuesReinette Chatre1-7/+7
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
2021-11-14Merge tag 'x86_urgent_for_v5.16_rc1' of ↵Linus Torvalds1-0/+9
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
2021-11-04Merge tag 'driver-core-5.16-rc1' of ↵Linus Torvalds1-54/+2
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 ...
2021-11-04x86/fpu: Optimize out sigframe xfeatures when in init stateDave Hansen1-0/+9
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: 2308ee57d93d ("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
2021-11-03Merge tag 'docs-5.16' of git://git.lwn.net/linuxLinus Torvalds2-3/+3
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 ...
2021-11-02Merge tag 'x86_sgx_for_v5.16_rc1' of ↵Linus Torvalds1-0/+35
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
2021-10-28Documentation/x86: Add documentation for using dynamic XSTATE featuresChang S. Bae2-0/+66
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
2021-10-22x86/sgx/virt: implement SGX_IOC_VEPC_REMOVE ioctlPaolo Bonzini1-0/+35
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
2021-10-12docs: use the lore redirector everywhereThorsten Leemhuis2-3/+3
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>
2021-10-05ABI: sysfs-mce: add a new ABI fileMauro Carvalho Chehab1-54/+2
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>
2021-09-09Merge tag 'docs-5.15-2' of git://git.lwn.net/linuxLinus Torvalds1-4/+0
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
2021-08-20docs: x86: Remove obsolete information about x86_64 vmalloc() faultingPeilin Ye1-4/+0
x86_64 vmalloc() mappings are no longer "synchronized" among page tables via faulting since commit 6eb82f994026 ("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 4819e15f740e ("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>
2021-08-12x86/reboot: Document how to override DMI platform quirksPaul Gortmaker1-0/+7
commit 5955633e91bf ("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
2021-08-12x86/reboot: Document the "reboot=pci" optionPaul Gortmaker1-1/+3
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
2021-07-07Merge tag 'x86-fpu-2021-07-07' of ↵Linus Torvalds2-0/+54
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() ...
2021-06-29Merge tag 'docs-5.14' of git://git.lwn.net/linuxLinus Torvalds2-3/+3
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 ...
2021-06-28Merge tag 'x86-splitlock-2021-06-28' of ↵Linus Torvalds2-0/+127
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
2021-06-17docs: x86: avoid using ReST :doc:`foo` markupMauro Carvalho Chehab2-3/+3
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>
2021-06-10doc: Remove references to IBM CalgaryHubert Jasudowicz1-30/+1
The Calgary IOMMU driver has been removed in 90dc392fc445 ("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
2021-05-19x86/elf: Support a new ELF aux vector AT_MINSIGSTKSZChang S. Bae2-0/+54
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 94b07c1f8c39 ("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
2021-05-18Documentation/x86: Add ratelimit in buslock.rstFenghua Yu1-0/+22
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
2021-05-18Documentation/x86: Add buslock.rstFenghua Yu2-0/+105
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
2021-05-10x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFGBrijesh Singh1-3/+3
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
2021-05-06Merge tag 'docs-5.13-2' of git://git.lwn.net/linuxLinus Torvalds1-2/+2
Pull documentation fixes from Jonathan Corbet: "A few late-arriving documentation fixes, including some oprofile cleanup, a kernel-doc fix, some regression-reporting updates, and the usual minor fixes" * tag 'docs-5.13-2' of git://git.lwn.net/linux: Enlisted oprofile version line removed oprofiled version output line removed from the list Removed the oprofiled version option docs: reporting-issues.rst: CC subsystem and maintainers on regressions docs: correct URL to bios and kernel developer's guide docs/core-api: Consistent code style docs/zh_CN: Adjust order and content of zh_CN/index.rst Documentation: input: joydev file corrections docs: Fix typo in Documentation/x86/x86_64/5level-paging.rst kernel-doc: Add support for __deprecated
2021-04-27docs: Fix typo in Documentation/x86/x86_64/5level-paging.rstbilbao@vt.edu1-2/+2
fix two typos in the documentation (Documentation/x86/x86_64/5level-paging.rst), changing 'paing' for 'paging' and using the right verbal form for plural on 'some vendors offer'. Signed-off-by: Carlos Bilbao <bilbao@vt.edu> Link: https://lore.kernel.org/r/2599991.mvXUDI8C0e@iron-maiden Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-06x86/sgx: Introduce virtual EPC for use by KVM guestsSean Christopherson1-0/+16
Add a misc device /dev/sgx_vepc to allow userspace to allocate "raw" Enclave Page Cache (EPC) without an associated enclave. The intended and only known use case for raw EPC allocation is to expose EPC to a KVM guest, hence the 'vepc' moniker, virt.{c,h} files and X86_SGX_KVM Kconfig. The SGX driver uses the misc device /dev/sgx_enclave to support userspace in creating an enclave. Each file descriptor returned from opening /dev/sgx_enclave represents an enclave. Unlike the SGX driver, KVM doesn't control how the guest uses the EPC, therefore EPC allocated to a KVM guest is not associated with an enclave, and /dev/sgx_enclave is not suitable for allocating EPC for a KVM guest. Having separate device nodes for the SGX driver and KVM virtual EPC also allows separate permission control for running host SGX enclaves and KVM SGX guests. To use /dev/sgx_vepc to allocate a virtual EPC instance with particular size, the hypervisor opens /dev/sgx_vepc, and uses mmap() with the intended size to get an address range of virtual EPC. Then it may use the address range to create one KVM memory slot as virtual EPC for a guest. Implement the "raw" EPC allocation in the x86 core-SGX subsystem via /dev/sgx_vepc rather than in KVM. Doing so has two major advantages: - Does not require changes to KVM's uAPI, e.g. EPC gets handled as just another memory backend for guests. - EPC management is wholly contained in the SGX subsystem, e.g. SGX does not have to export any symbols, changes to reclaim flows don't need to be routed through KVM, SGX's dirty laundry doesn't have to get aired out for the world to see, and so on and so forth. The virtual EPC pages allocated to guests are currently not reclaimable. Reclaiming an EPC page used by enclave requires a special reclaim mechanism separate from normal page reclaim, and that mechanism is not supported for virutal EPC pages. Due to the complications of handling reclaim conflicts between guest and host, reclaiming virtual EPC pages is significantly more complex than basic support for SGX virtualization. [ bp: - Massage commit message and comments - use cpu_feature_enabled() - vertically align struct members init - massage Virtual EPC clarification text - move Kconfig prompt to Virtualization ] Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lkml.kernel.org/r/0c38ced8c8e5a69872db4d6a1c0dabd01e07cad7.1616136308.git.kai.huang@intel.com
2021-03-27x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()Kai Huang1-0/+25
EREMOVE takes a page and removes any association between that page and an enclave. It must be run on a page before it can be added into another enclave. Currently, EREMOVE is run as part of pages being freed into the SGX page allocator. It is not expected to fail, as it would indicate a use-after-free of EPC pages. Rather than add the page back to the pool of available EPC pages, the kernel intentionally leaks the page to avoid additional errors in the future. However, KVM does not track how guest pages are used, which means that SGX virtualization use of EREMOVE might fail. Specifically, it is legitimate that EREMOVE returns SGX_CHILD_PRESENT for EPC assigned to KVM guest, because KVM/kernel doesn't track SECS pages. To allow SGX/KVM to introduce a more permissive EREMOVE helper and to let the SGX virtualization code use the allocator directly, break out the EREMOVE call from the SGX page allocator. Rename the original sgx_free_epc_page() to sgx_encl_free_epc_page(), indicating that it is used to free an EPC page assigned to a host enclave. Replace sgx_free_epc_page() with sgx_encl_free_epc_page() in all call sites so there's no functional change. At the same time, improve the error message when EREMOVE fails, and add documentation to explain to the user what that failure means and to suggest to the user what to do when this bug happens in the case it happens. [ bp: Massage commit message, fix typos and sanitize text, simplify. ] Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lkml.kernel.org/r/20210325093057.122834-1-kai.huang@intel.com
2021-01-29Documentation/x86/boot.rst: Correct the example of SETUP_INDIRECTCao jin1-1/+1
struct setup_data.len is the length of data field. In case of SETUP_INDIRECT, it should be sizeof(setup_indirect). Signed-off-by: Cao jin <jojing64@gmail.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Link: https://lore.kernel.org/r/20210127084911.63438-1-jojing64@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-15Merge tag 'docs-5.11' of git://git.lwn.net/linuxLinus Torvalds2-0/+4
Pull documentation updates from Jonathan Corbet: "A much quieter cycle for documentation (happily), with, one hopes, the bulk of the churn behind us. Significant stuff in this pull includes: - A set of new Chinese translations - Italian translation updates - A mechanism from Mauro to automatically format Documentation/features for the built docs - Automatic cross references without explicit :ref: markup - A new reset-controller document - An extensive new document on reporting problems from Thorsten That last patch also adds the CC-BY-4.0 license to LICENSES/dual; there was some discussion on this, but we seem to have consensus and an ack from Greg for that addition" * tag 'docs-5.11' of git://git.lwn.net/linux: (50 commits) docs: fix broken cross reference in translations/zh_CN docs: Note that sphinx 1.7 will be required soon docs: update requirements to install six module docs: reporting-issues: move 'outdated, need help' note to proper place docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means docs: add a reset controller chapter to the driver API docs docs: make reporting-bugs.rst obsolete docs: Add a new text describing how to report bugs LICENSES: Add the CC-BY-4.0 license Documentation: fix multiple typos found in the admin-guide subdirectory Documentation: fix typos found in admin-guide subdirectory kernel-doc: Fix example in Nested structs/unions docs: clean up sysctl/kernel: titles, version docs: trace: fix event state structure name docs: nios2: add missing ReST file scripts: get_feat.pl: reduce table width for all features output scripts: get_feat.pl: change the group by order scripts: get_feat.pl: make complete table more coincise scripts: kernel-doc: fix parsing function-like typedefs Documentation: fix typos found in process, dev-tools, and doc-guide subdirectories ...
2020-12-15Merge tag 'x86_cache_for_v5.11' of ↵Linus Torvalds2-1/+94
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache resource control updates from Borislav Petkov: - add logic to correct MBM total and local values fixing errata SKX99 and BDF102 (Fenghua Yu) - cleanups * tag 'x86_cache_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Clean up unused function parameter in rmdir path x86/resctrl: Constify kernfs_ops x86/resctrl: Correct MBM total and local values Documentation/x86: Rename resctrl_ui.rst and add two errata to the file