linux-stable.git/Documentation/admin-guide, branch v6.1.2 Linux kernel stable tree x86/split_lock: Add sysctl to control the misery mode 2022-12-31T12:31:55+00:00 Guilherme G. Piccoli gpiccoli@igalia.com 2022-10-24T20:02:54+00:00 bb1878d741ffe848c05313b99e0938621e1df0ce [ Upstream commit 727209376f4998bc84db1d5d8af15afea846a92b ] Commit b041b525dab9 ("x86/split_lock: Make life miserable for split lockers") changed the way the split lock detector works when in "warn" mode; basically, it not only shows the warn message, but also intentionally introduces a slowdown through sleeping plus serialization mechanism on such task. Based on discussions in [0], seems the warning alone wasn't enough motivation for userspace developers to fix their applications. This slowdown is enough to totally break some proprietary (aka. unfixable) userspace[1]. Happens that originally the proposal in [0] was to add a new mode which would warns + slowdown the "split locking" task, keeping the old warn mode untouched. In the end, that idea was discarded and the regular/default "warn" mode now slows down the applications. This is quite aggressive with regards proprietary/legacy programs that basically are unable to properly run in kernel with this change. While it is understandable that a malicious application could DoS by split locking, it seems unacceptable to regress old/proprietary userspace programs through a default configuration that previously worked. An example of such breakage was reported in [1]. Add a sysctl to allow controlling the "misery mode" behavior, as per Thomas suggestion on [2]. This way, users running legacy and/or proprietary software are allowed to still execute them with a decent performance while still observing the warning messages on kernel log. [0] https://lore.kernel.org/lkml/20220217012721.9694-1-tony.luck@intel.com/ [1] https://github.com/doitsujin/dxvk/issues/2938 [2] https://lore.kernel.org/lkml/87pmf4bter.ffs@tglx/ [ dhansen: minor changelog tweaks, including clarifying the actual problem ] Fixes: b041b525dab9 ("x86/split_lock: Make life miserable for split lockers") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Tested-by: Andre Almeida <andrealmeid@igalia.com> Link: https://lore.kernel.org/all/20221024200254.635256-1-gpiccoli%40igalia.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 727209376f4998bc84db1d5d8af15afea846a92b ]

Commit b041b525dab9 ("x86/split_lock: Make life miserable for split lockers")
changed the way the split lock detector works when in "warn" mode;
basically, it not only shows the warn message, but also intentionally
introduces a slowdown through sleeping plus serialization mechanism
on such task. Based on discussions in [0], seems the warning alone
wasn't enough motivation for userspace developers to fix their
applications.

This slowdown is enough to totally break some proprietary (aka.
unfixable) userspace[1].

Happens that originally the proposal in [0] was to add a new mode
which would warns + slowdown the "split locking" task, keeping the
old warn mode untouched. In the end, that idea was discarded and
the regular/default "warn" mode now slows down the applications. This
is quite aggressive with regards proprietary/legacy programs that
basically are unable to properly run in kernel with this change.
While it is understandable that a malicious application could DoS
by split locking, it seems unacceptable to regress old/proprietary
userspace programs through a default configuration that previously
worked. An example of such breakage was reported in [1].

Add a sysctl to allow controlling the "misery mode" behavior, as per
Thomas suggestion on [2]. This way, users running legacy and/or
proprietary software are allowed to still execute them with a decent
performance while still observing the warning messages on kernel log.

[0] https://lore.kernel.org/lkml/20220217012721.9694-1-tony.luck@intel.com/
[1] https://github.com/doitsujin/dxvk/issues/2938
[2] https://lore.kernel.org/lkml/87pmf4bter.ffs@tglx/

[ dhansen: minor changelog tweaks, including clarifying the actual
  	   problem ]

Fixes: b041b525dab9 ("x86/split_lock: Make life miserable for split lockers")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Andre Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20221024200254.635256-1-gpiccoli%40igalia.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Documentation: add amd-pstate kernel command line options 2022-11-22T18:57:15+00:00 Perry Yuan Perry.Yuan@amd.com 2022-11-17T07:35:41+00:00 1056d314709d0607a22e589c54b1e47e0da57b9d Add a new amd pstate driver command line option to enable driver passive working mode via MSR and shared memory interface to request desired performance within abstract scale and the power management firmware (SMU) convert the perf requests into actual hardware pstates. Also the `disable` parameter can disable the pstate driver loading by adding `amd_pstate=disable` to kernel command line. Acked-by: Huang Rui <ray.huang@amd.com> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Tested-by: Wyes Karny <wyes.karny@amd.com> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Add a new amd pstate driver command line option to enable driver passive
working mode via MSR and shared memory interface to request desired
performance within abstract scale and the power management firmware
(SMU) convert the perf requests into actual hardware pstates.

Also the `disable` parameter can disable the pstate driver loading by
adding `amd_pstate=disable` to kernel command line.

Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Documentation: amd-pstate: add driver working mode introduction 2022-11-22T18:57:15+00:00 Perry Yuan Perry.Yuan@amd.com 2022-11-17T07:35:40+00:00 8a2cbf72a43ade1ed00760f65914e322599fe662 Introduce the `amd_pstate` driver new working mode with `amd_pstate=passive` added to kernel command line. If there is no passive mode enabled by user, amd_pstate driver will be disabled by default for now. Acked-by: Huang Rui <ray.huang@amd.com> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Tested-by: Wyes Karny <wyes.karny@amd.com> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Introduce the `amd_pstate` driver new working mode with
`amd_pstate=passive` added to kernel command line.
If there is no passive mode enabled by user, amd_pstate driver will be
disabled by default for now.

Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
media: vivid.rst: loop_video is set on the capture devnode 2022-10-25T15:43:54+00:00 Hans Verkuil hverkuil-cisco@xs4all.nl 2022-10-17T14:15:05+00:00 de547896aac606a00435a219757a940ece142bf0 The example on how to use and test Capture Overlay specified the wrong video device node. Back in 2015 the loop_video control moved from the output device to the capture device, but this example code is still referring to the output video device. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> 
The example on how to use and test Capture Overlay specified
the wrong video device node. Back in 2015 the loop_video control
moved from the output device to the capture device, but this
example code is still referring to the output video device.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Merge tag 'acpi-6.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 2022-10-22T01:08:30+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-10-22T01:08:30+00:00 9d6e681d33943e7e5b26b945e680a71311683795 Pull ACPI fixes from Rafael Wysocki: "These fix issues introduced during this merge window (ACPI/PCI, device enumeration and documentation) and some other ones found recently. Specifics: - Add missing device reference counting to acpi_get_pci_dev() after changing it recently (Rafael Wysocki) - Fix resource list walk in acpi_dma_get_range() (Robin Murphy) - Add IRQ override quirk for LENOVO IdeaPad and extend the IRQ override warning message (Jiri Slaby) - Fix integer overflow in ghes_estatus_pool_init() (Ashish Kalra) - Fix multiple error records handling in one of the ACPI extlog driver code paths (Tony Luck) - Prune DSDT override documentation from index after dropping it (Bagas Sanjaya)" * tag 'acpi-6.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: scan: Fix DMA range assignment ACPI: PCI: Fix device reference counting in acpi_get_pci_dev() ACPI: resource: note more about IRQ override ACPI: resource: do IRQ override on LENOVO IdeaPad ACPI: extlog: Handle multiple records ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init() Documentation: ACPI: Prune DSDT override documentation from index 
Pull ACPI fixes from Rafael Wysocki:
 "These fix issues introduced during this merge window (ACPI/PCI, device
  enumeration and documentation) and some other ones found recently.

  Specifics:

   - Add missing device reference counting to acpi_get_pci_dev() after
     changing it recently (Rafael Wysocki)

   - Fix resource list walk in acpi_dma_get_range() (Robin Murphy)

   - Add IRQ override quirk for LENOVO IdeaPad and extend the IRQ
     override warning message (Jiri Slaby)

   - Fix integer overflow in ghes_estatus_pool_init() (Ashish Kalra)

   - Fix multiple error records handling in one of the ACPI extlog
     driver code paths (Tony Luck)

   - Prune DSDT override documentation from index after dropping it
     (Bagas Sanjaya)"

* tag 'acpi-6.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: scan: Fix DMA range assignment
  ACPI: PCI: Fix device reference counting in acpi_get_pci_dev()
  ACPI: resource: note more about IRQ override
  ACPI: resource: do IRQ override on LENOVO IdeaPad
  ACPI: extlog: Handle multiple records
  ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init()
  Documentation: ACPI: Prune DSDT override documentation from index
Merge branches 'acpi-scan', 'acpi-resource', 'acpi-apei', 'acpi-extlog' and 'acpi-docs' 2022-10-21T18:07:41+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2022-10-21T18:07:41+00:00 3f8deab61ea86d738a1e7fdf95e9ad2bf08d14b8 Merge assorted ACPI fixes for 6.1-rc2: - Fix resource list walk in acpi_dma_get_range() (Robin Murphy). - Add IRQ override quirk for LENOVO IdeaPad and extend the IRQ override warning message (Jiri Slaby). - Fix integer overflow in ghes_estatus_pool_init() (Ashish Kalra). - Fix multiple error records handling in one of the ACPI extlog driver code paths (Tony Luck). - Prune DSDT override documentation from index after dropping it (Bagas Sanjaya). * acpi-scan: ACPI: scan: Fix DMA range assignment * acpi-resource: ACPI: resource: note more about IRQ override ACPI: resource: do IRQ override on LENOVO IdeaPad * acpi-apei: ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init() * acpi-extlog: ACPI: extlog: Handle multiple records * acpi-docs: Documentation: ACPI: Prune DSDT override documentation from index 
Merge assorted ACPI fixes for 6.1-rc2:

 - Fix resource list walk in acpi_dma_get_range() (Robin Murphy).

 - Add IRQ override quirk for LENOVO IdeaPad and extend the IRQ
   override warning message (Jiri Slaby).

 - Fix integer overflow in ghes_estatus_pool_init() (Ashish Kalra).

 - Fix multiple error records handling in one of the ACPI extlog driver
   code paths (Tony Luck).

 - Prune DSDT override documentation from index after dropping it (Bagas
   Sanjaya).

* acpi-scan:
  ACPI: scan: Fix DMA range assignment

* acpi-resource:
  ACPI: resource: note more about IRQ override
  ACPI: resource: do IRQ override on LENOVO IdeaPad

* acpi-apei:
  ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init()

* acpi-extlog:
  ACPI: extlog: Handle multiple records

* acpi-docs:
  Documentation: ACPI: Prune DSDT override documentation from index
dm verity: Add documentation for try_verify_in_tasklet option 2022-10-18T21:17:48+00:00 Milan Broz gmazyland@gmail.com 2022-09-27T18:42:26+00:00 dc3efedf9f7b802d0817183020ed01cb0c120fe8 Add documentation that was missing from commit 5721d4e5a9cd ("dm verity: Add optional "try_verify_in_tasklet" feature"). Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> 
Add documentation that was missing from commit 5721d4e5a9cd ("dm
verity: Add optional "try_verify_in_tasklet" feature").

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Merge tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2022-10-14T20:03:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-10-14T20:03:00+00:00 bd9a3dba185ce6701b41f0341470d3f53bbbbaed Pull PSI updates from Ingo Molnar: - Various performance optimizations, resulting in a 4%-9% speedup in the mmtests/config-scheduler-perfpipe micro-benchmark. - New interface to turn PSI on/off on a per cgroup level. * tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/psi: Per-cgroup PSI accounting disable/re-enable interface sched/psi: Cache parent psi_group to speed up group iteration sched/psi: Consolidate cgroup_psi() sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure sched/psi: Remove NR_ONCPU task accounting sched/psi: Optimize task switch inside shared cgroups again sched/psi: Move private helpers to sched/stats.h sched/psi: Save percpu memory when !psi_cgroups_enabled sched/psi: Don't create cgroup PSI files when psi_disabled sched/psi: Fix periodic aggregation shut off 
Pull PSI updates from Ingo Molnar:

 - Various performance optimizations, resulting in a 4%-9% speedup in
   the mmtests/config-scheduler-perfpipe micro-benchmark.

 - New interface to turn PSI on/off on a per cgroup level.

* tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/psi: Per-cgroup PSI accounting disable/re-enable interface
  sched/psi: Cache parent psi_group to speed up group iteration
  sched/psi: Consolidate cgroup_psi()
  sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure
  sched/psi: Remove NR_ONCPU task accounting
  sched/psi: Optimize task switch inside shared cgroups again
  sched/psi: Move private helpers to sched/stats.h
  sched/psi: Save percpu memory when !psi_cgroups_enabled
  sched/psi: Don't create cgroup PSI files when psi_disabled
  sched/psi: Fix periodic aggregation shut off
Documentation: ACPI: Prune DSDT override documentation from index 2022-10-13T18:33:12+00:00 Bagas Sanjaya bagasdotme@gmail.com 2022-10-11T12:26:01+00:00 83439a0f1ce6a592f95e41338320b5f01b98a356 Commit d206cef03c4827 ("ACPI: docs: Drop useless DSDT override documentation") removes useless DSDT override documentation. However, the commit forgets to prune the documentation entry from table of contents of ACPI admin guide documentation, hence triggers Sphinx warning: Documentation/admin-guide/acpi/index.rst:8: WARNING: toctree contains reference to nonexisting document 'admin-guide/acpi/dsdt-override' Prune the entry to fix the warning. Fixes: d206cef03c4827 ("ACPI: docs: Drop useless DSDT override documentation") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Commit d206cef03c4827 ("ACPI: docs: Drop useless DSDT override documentation")
removes useless DSDT override documentation. However, the commit forgets
to prune the documentation entry from table of contents of ACPI admin
guide documentation, hence triggers Sphinx warning:

Documentation/admin-guide/acpi/index.rst:8: WARNING: toctree contains reference to nonexisting document 'admin-guide/acpi/dsdt-override'

Prune the entry to fix the warning.

Fixes: d206cef03c4827 ("ACPI: docs: Drop useless DSDT override documentation")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge tag 'for-linus-6.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 2022-10-12T21:39:38+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-10-12T21:39:38+00:00 778ce723e93ee803ef5883619fe2391e00dbc209 Pull xen updates from Juergen Gross: - Some minor typo fixes - A fix of the Xen pcifront driver for supporting the device model to run in a Linux stub domain - A cleanup of the pcifront driver - A series to enable grant-based virtio with Xen on x86 - A cleanup of Xen PV guests to distinguish between safe and faulting MSR accesses - Two fixes of the Xen gntdev driver - Two fixes of the new xen grant DMA driver * tag 'for-linus-6.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Kconfig: Fix spelling mistake "Maxmium" -> "Maximum" xen/pv: support selecting safe/unsafe msr accesses xen/pv: refactor msr access functions to support safe and unsafe accesses xen/pv: fix vendor checks for pmu emulation xen/pv: add fault recovery control to pmu msr accesses xen/virtio: enable grant based virtio on x86 xen/virtio: use dom0 as default backend for CONFIG_XEN_VIRTIO_FORCE_GRANT xen/virtio: restructure xen grant dma setup xen/pcifront: move xenstore config scanning into sub-function xen/gntdev: Accommodate VMA splitting xen/gntdev: Prevent leaking grants xen/virtio: Fix potential deadlock when accessing xen_grant_dma_devices xen/virtio: Fix n_pages calculation in xen_grant_dma_map(unmap)_page() xen/xenbus: Fix spelling mistake "hardward" -> "hardware" xen-pcifront: Handle missed Connected state 
Pull xen updates from Juergen Gross:

 - Some minor typo fixes

 - A fix of the Xen pcifront driver for supporting the device model to
   run in a Linux stub domain

 - A cleanup of the pcifront driver

 - A series to enable grant-based virtio with Xen on x86

 - A cleanup of Xen PV guests to distinguish between safe and faulting
   MSR accesses

 - Two fixes of the Xen gntdev driver

 - Two fixes of the new xen grant DMA driver

* tag 'for-linus-6.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Kconfig: Fix spelling mistake "Maxmium" -> "Maximum"
  xen/pv: support selecting safe/unsafe msr accesses
  xen/pv: refactor msr access functions to support safe and unsafe accesses
  xen/pv: fix vendor checks for pmu emulation
  xen/pv: add fault recovery control to pmu msr accesses
  xen/virtio: enable grant based virtio on x86
  xen/virtio: use dom0 as default backend for CONFIG_XEN_VIRTIO_FORCE_GRANT
  xen/virtio: restructure xen grant dma setup
  xen/pcifront: move xenstore config scanning into sub-function
  xen/gntdev: Accommodate VMA splitting
  xen/gntdev: Prevent leaking grants
  xen/virtio: Fix potential deadlock when accessing xen_grant_dma_devices
  xen/virtio: Fix n_pages calculation in xen_grant_dma_map(unmap)_page()
  xen/xenbus: Fix spelling mistake "hardward" -> "hardware"
  xen-pcifront: Handle missed Connected state