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
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
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
...
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
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 ...
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
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
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
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>
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>