diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 6 | ||||
| -rw-r--r-- | Documentation/admin-guide/device-mapper/dm-integrity.rst | 12 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 90 | ||||
| -rw-r--r-- | Documentation/admin-guide/media/rkisp1.rst | 16 | ||||
| -rw-r--r-- | Documentation/admin-guide/perf/arm-cmn.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/syscall-user-dispatch.rst | 4 | ||||
| -rw-r--r-- | Documentation/admin-guide/thunderbolt.rst | 23 | ||||
| -rw-r--r-- | Documentation/admin-guide/xfs.rst | 42 |
8 files changed, 155 insertions, 40 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 63521cd36ce5..1de8695c264b 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1029,7 +1029,7 @@ All time durations are in microseconds. one number is written, $MAX is updated. cpu.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-write nested-keyed file. Shows pressure stall information for CPU. See :ref:`Documentation/accounting/psi.rst <psi>` for details. @@ -1475,7 +1475,7 @@ PAGE_SIZE multiple when read back. reduces the impact on the workload and memory management. memory.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-only nested-keyed file. Shows pressure stall information for memory. See :ref:`Documentation/accounting/psi.rst <psi>` for details. @@ -1714,7 +1714,7 @@ IO Interface Files 8:16 rbps=2097152 wbps=max riops=max wiops=max io.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-only nested-keyed file. Shows pressure stall information for IO. See :ref:`Documentation/accounting/psi.rst <psi>` for details. diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 4e6f504474ac..2cc5488acbd9 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -177,14 +177,20 @@ bitmap_flush_interval:number The bitmap flush interval in milliseconds. The metadata buffers are synchronized when this interval expires. +allow_discards + Allow block discard requests (a.k.a. TRIM) for the integrity device. + Discards are only allowed to devices using internal hash. + fix_padding Use a smaller padding of the tag area that is more space-efficient. If this option is not present, large padding is used - that is for compatibility with older kernels. -allow_discards - Allow block discard requests (a.k.a. TRIM) for the integrity device. - Discards are only allowed to devices using internal hash. +legacy_recalculate + Allow recalculating of volumes with HMAC keys. This is disabled by + default for security reasons - an attacker could modify the volume, + set recalc_sector to zero, and the kernel would not detect the + modification. The journal mode (D/J), buffer_sectors, journal_watermark, commit_time and allow_discards can be changed when reloading the target (load an inactive diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 65a0c4c9ab18..4fc20f9af2fb 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -373,6 +373,12 @@ arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards Format: <io>,<irq>,<nodeID> + arm64.nobti [ARM64] Unconditionally disable Branch Target + Identification support + + arm64.nopauth [ARM64] Unconditionally disable Pointer Authentication + support + ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse @@ -802,13 +808,14 @@ insecure, please do not use on production kernels. debug_locks_verbose= - [KNL] verbose self-tests - Format=<0|1> + [KNL] verbose locking self-tests + Format: <int> Print debugging info while doing the locking API self-tests. - We default to 0 (no extra messages), setting it to - 1 will print _a lot_ more information - normally - only useful to kernel developers. + Bitmask for the various LOCKTYPE_ tests. Defaults to 0 + (no extra messages), setting it to -1 (all bits set) + will print _a_lot_ more information - normally only + useful to lockdep developers. debug_objects [KNL] Enable object debugging @@ -944,12 +951,6 @@ causing system reset or hang due to sending INIT from AP to BSP. - perf_v4_pmi= [X86,INTEL] - Format: <bool> - Disable Intel PMU counter freezing feature. - The feature only exists starting from - Arch Perfmon v4 (Skylake and newer). - disable_ddw [PPC/PSERIES] Disable Dynamic DMA Window support. Use this to workaround buggy firmware. @@ -2260,6 +2261,9 @@ kvm-arm.mode= [KVM,ARM] Select one of KVM/arm64's modes of operation. + nvhe: Standard nVHE-based mode, without support for + protected guests. + protected: nVHE-based mode with support for guests whose state is kept private from the host. Not valid if the kernel is running in EL2. @@ -3461,20 +3465,6 @@ For example, to override I2C bus2: omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 - oprofile.timer= [HW] - Use timer interrupt instead of performance counters - - oprofile.cpu_type= Force an oprofile cpu type - This might be useful if you have an older oprofile - userland or if you want common events. - Format: { arch_perfmon } - arch_perfmon: [X86] Force use of architectural - perfmon on Intel CPUs instead of the - CPU specific event set. - timer: [X86] Force use of architectural NMI - timer mode (see also oprofile.timer - for generic hr timer mode) - oops=panic Always panic on oopses. Default is to just kill the process, but there is a small probability of deadlocking the machine. @@ -3919,6 +3909,13 @@ Format: {"off"} Disable Hardware Transactional Memory + preempt= [KNL] + Select preemption mode if you have CONFIG_PREEMPT_DYNAMIC + none - Limited to cond_resched() calls + voluntary - Limited to cond_resched() and might_sleep() calls + full - Any section that isn't explicitly preempt disabled + can be preempted anytime. + print-fatal-signals= [KNL] debug: print fatal signals @@ -4095,6 +4092,10 @@ value, meaning that RCU_SOFTIRQ is used by default. Specify rcutree.use_softirq=0 to use rcuc kthreads. + But note that CONFIG_PREEMPT_RT=y kernels disable + this kernel boot parameter, forcibly setting it + to zero. + rcutree.rcu_fanout_exact= [KNL] Disable autobalancing of the rcu_node combining tree. This is used by rcutorture, and might @@ -4182,12 +4183,6 @@ Set wakeup interval for idle CPUs that have RCU callbacks (RCU_FAST_NO_HZ=y). - rcutree.rcu_idle_lazy_gp_delay= [KNL] - Set wakeup interval for idle CPUs that have - only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). - Lazy RCU callbacks are those which RCU can - prove do nothing more than free memory. - rcutree.rcu_kick_kthreads= [KNL] Cause the grace-period kthread to get an extra wake_up() if it sleeps three times longer than @@ -4341,6 +4336,14 @@ stress RCU, they don't participate in the actual test, hence the "fake". + rcutorture.nocbs_nthreads= [KNL] + Set number of RCU callback-offload togglers. + Zero (the default) disables toggling. + + rcutorture.nocbs_toggle= [KNL] + Set the delay in milliseconds between successive + callback-offload toggling attempts. + rcutorture.nreaders= [KNL] Set number of RCU readers. The value -1 selects N-1, where N is the number of CPUs. A value @@ -4473,6 +4476,13 @@ only normal grace-period primitives. No effect on CONFIG_TINY_RCU kernels. + But note that CONFIG_PREEMPT_RT=y kernels enables + this kernel boot parameter, forcibly setting + it to the value one, that is, converting any + post-boot attempt at an expedited RCU grace + period to instead use normal non-expedited + grace-period processing. + rcupdate.rcu_task_ipi_delay= [KNL] Set time in jiffies during which RCU tasks will avoid sending IPIs, starting with the beginning @@ -4560,6 +4570,12 @@ refscale.verbose= [KNL] Enable additional printk() statements. + refscale.verbose_batched= [KNL] + Batch the additional printk() statements. If zero + (the default) or negative, print everything. Otherwise, + print every Nth verbose statement, where N is the value + specified. + relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. See Documentation/admin-guide/cgroup-v1/cpusets.rst. @@ -5334,6 +5350,14 @@ are running concurrently, especially on systems with rotating-rust storage. + torture.verbose_sleep_frequency= [KNL] + Specifies how many verbose printk()s should be + emitted between each sleep. The default of zero + disables verbose-printk() sleeping. + + torture.verbose_sleep_duration= [KNL] + Duration of each verbose-printk() sleep in jiffies. + tp720= [HW,PS2] tpm_suspend_pcr=[HW,TPM] @@ -5975,6 +5999,10 @@ This option is obsoleted by the "nopv" option, which has equivalent effect for XEN platform. + xen_no_vector_callback + [KNL,X86,XEN] Disable the vector callback for Xen + event channel interrupts. + xen_scrub_pages= [XEN] Boolean option to control scrubbing pages before giving them back to Xen, for use by other domains. Can be also changed at runtime diff --git a/Documentation/admin-guide/media/rkisp1.rst b/Documentation/admin-guide/media/rkisp1.rst index 2267e4fb475e..ccf418713623 100644 --- a/Documentation/admin-guide/media/rkisp1.rst +++ b/Documentation/admin-guide/media/rkisp1.rst @@ -13,6 +13,22 @@ This file documents the driver for the Rockchip ISP1 that is part of RK3288 and RK3399 SoCs. The driver is located under drivers/staging/media/rkisp1 and uses the Media-Controller API. +Revisions +========= + +There exist multiple smaller revisions to this ISP that got introduced in +later SoCs. Revisions can be found in the enum :c:type:`rkisp1_cif_isp_version` +in the UAPI and the revision of the ISP inside the running SoC can be read +in the field hw_revision of struct media_device_info as returned by +ioctl MEDIA_IOC_DEVICE_INFO. + +Versions in use are: + +- RKISP1_V10: used at least in rk3288 and rk3399 +- RKISP1_V11: declared in the original vendor code, but not used +- RKISP1_V12: used at least in rk3326 and px30 +- RKISP1_V13: used at least in rk1808 + Topology ======== .. _rkisp1_topology_graph: diff --git a/Documentation/admin-guide/perf/arm-cmn.rst b/Documentation/admin-guide/perf/arm-cmn.rst index 0e4809346014..796e25b7027b 100644 --- a/Documentation/admin-guide/perf/arm-cmn.rst +++ b/Documentation/admin-guide/perf/arm-cmn.rst @@ -17,7 +17,7 @@ PMU events ---------- The PMU driver registers a single PMU device for the whole interconnect, -see /sys/bus/event_source/devices/arm_cmn. Multi-chip systems may link +see /sys/bus/event_source/devices/arm_cmn_0. Multi-chip systems may link more than one CMN together via external CCIX links - in this situation, each mesh counts its own events entirely independently, and additional PMU devices will be named arm_cmn_{1..n}. diff --git a/Documentation/admin-guide/syscall-user-dispatch.rst b/Documentation/admin-guide/syscall-user-dispatch.rst index a380d6515774..60314953c728 100644 --- a/Documentation/admin-guide/syscall-user-dispatch.rst +++ b/Documentation/admin-guide/syscall-user-dispatch.rst @@ -70,8 +70,8 @@ trampoline code on the vDSO, that trampoline is never intercepted. [selector] is a pointer to a char-sized region in the process memory region, that provides a quick way to enable disable syscall redirection thread-wide, without the need to invoke the kernel directly. selector -can be set to PR_SYS_DISPATCH_ON or PR_SYS_DISPATCH_OFF. Any other -value should terminate the program with a SIGSYS. +can be set to SYSCALL_DISPATCH_FILTER_ALLOW or SYSCALL_DISPATCH_FILTER_BLOCK. +Any other value should terminate the program with a SIGSYS. Security Notes -------------- diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 613cb24c76c7..f18e881373c4 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -47,6 +47,9 @@ be DMA masters and thus read contents of the host memory without CPU and OS knowing about it. There are ways to prevent this by setting up an IOMMU but it is not always available for various reasons. +Some USB4 systems have a BIOS setting to disable PCIe tunneling. This is +treated as another security level (nopcie). + The security levels are as follows: none @@ -77,6 +80,10 @@ The security levels are as follows: Display Port in a dock. All PCIe links downstream of the dock are removed. + nopcie + PCIe tunneling is disabled/forbidden from the BIOS. Available in some + USB4 systems. + The current security level can be read from ``/sys/bus/thunderbolt/devices/domainX/security`` where ``domainX`` is the Thunderbolt domain the host controller manages. There is typically @@ -153,6 +160,22 @@ If the user still wants to connect the device they can either approve the device without a key or write a new key and write 1 to the ``authorized`` file to get the new key stored on the device NVM. +De-authorizing devices +---------------------- +It is possible to de-authorize devices by writing ``0`` to their +``authorized`` attribute. This requires support from the connection +manager implementation and can be checked by reading domain +``deauthorization`` attribute. If it reads ``1`` then the feature is +supported. + +When a device is de-authorized the PCIe tunnel from the parent device +PCIe downstream (or root) port to the device PCIe upstream port is torn +down. This is essentially the same thing as PCIe hot-remove and the PCIe +toplogy in question will not be accessible anymore until the device is +authorized again. If there is storage such as NVMe or similar involved, +there is a risk for data loss if the filesystem on that storage is not +properly shut down. You have been warned! + DMA protection utilizing IOMMU ------------------------------ Recent systems from 2018 and forward with Thunderbolt ports may natively diff --git a/Documentation/admin-guide/xfs.rst b/Documentation/admin-guide/xfs.rst index 86de8a1ad91c..6178153d3320 100644 --- a/Documentation/admin-guide/xfs.rst +++ b/Documentation/admin-guide/xfs.rst @@ -495,3 +495,45 @@ the class and error context. For example, the default values for "metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults to "fail immediately" behaviour. This is done because ENODEV is a fatal, unrecoverable error no matter how many times the metadata IO is retried. + +Workqueue Concurrency +===================== + +XFS uses kernel workqueues to parallelize metadata update processes. This +enables it to take advantage of storage hardware that can service many IO +operations simultaneously. This interface exposes internal implementation +details of XFS, and as such is explicitly not part of any userspace API/ABI +guarantee the kernel may give userspace. These are undocumented features of +the generic workqueue implementation XFS uses for concurrency, and they are +provided here purely for diagnostic and tuning purposes and may change at any +time in the future. + +The control knobs for a filesystem's workqueues are organized by task at hand +and the short name of the data device. They all can be found in: + + /sys/bus/workqueue/devices/${task}!${device} + +================ =========== + Task Description +================ =========== + xfs_iwalk-$pid Inode scans of the entire filesystem. Currently limited to + mount time quotacheck. + xfs-blockgc Background garbage collection of disk space that have been + speculatively allocated beyond EOF or for staging copy on + write operations. +================ =========== + +For example, the knobs for the quotacheck workqueue for /dev/nvme0n1 would be +found in /sys/bus/workqueue/devices/xfs_iwalk-1111!nvme0n1/. + +The interesting knobs for XFS workqueues are as follows: + +============ =========== + Knob Description +============ =========== + max_active Maximum number of background threads that can be started to + run the work. + cpumask CPUs upon which the threads are allowed to run. + nice Relative priority of scheduling the threads. These are the + same nice levels that can be applied to userspace processes. +============ =========== |