diff options
Diffstat (limited to 'Documentation')
18 files changed, 145 insertions, 113 deletions
diff --git a/Documentation/ABI/testing/sysfs-timecard b/Documentation/ABI/testing/sysfs-timecard index 220478156297..3ae41b7634ac 100644 --- a/Documentation/ABI/testing/sysfs-timecard +++ b/Documentation/ABI/testing/sysfs-timecard @@ -258,24 +258,29 @@ Description: (RW) When retrieving the PHC with the PTP SYS_OFFSET_EXTENDED the estimated point where the FPGA latches the PHC time. This value may be changed by writing an unsigned integer. -What: /sys/class/timecard/ocpN/ttyGNSS -What: /sys/class/timecard/ocpN/ttyGNSS2 -Date: September 2021 +What: /sys/class/timecard/ocpN/tty +Date: August 2024 +Contact: Vadim Fedorenko <vadim.fedorenko@linux.dev> +Description: (RO) Directory containing the sysfs nodes for TTY attributes + +What: /sys/class/timecard/ocpN/tty/ttyGNSS +What: /sys/class/timecard/ocpN/tty/ttyGNSS2 +Date: August 2024 Contact: Jonathan Lemon <jonathan.lemon@gmail.com> -Description: These optional attributes link to the TTY serial ports - associated with the GNSS devices. +Description: (RO) These optional attributes contain names of the TTY serial + ports associated with the GNSS devices. -What: /sys/class/timecard/ocpN/ttyMAC -Date: September 2021 +What: /sys/class/timecard/ocpN/tty/ttyMAC +Date: August 2024 Contact: Jonathan Lemon <jonathan.lemon@gmail.com> -Description: This optional attribute links to the TTY serial port - associated with the Miniature Atomic Clock. +Description: (RO) This optional attribute contains name of the TTY serial + port associated with the Miniature Atomic Clock. -What: /sys/class/timecard/ocpN/ttyNMEA -Date: September 2021 +What: /sys/class/timecard/ocpN/tty/ttyNMEA +Date: August 2024 Contact: Jonathan Lemon <jonathan.lemon@gmail.com> -Description: This optional attribute links to the TTY serial port - which outputs the PHC time in NMEA ZDA format. +Description: (RO) This optional attribute contains name of the TTY serial + port which outputs the PHC time in NMEA ZDA format. What: /sys/class/timecard/ocpN/utc_tai_offset Date: September 2021 diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 86311c2907cd..95c18bc17083 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1717,9 +1717,10 @@ The following nested keys are defined. entries fault back in or are written out to disk. memory.zswap.writeback - A read-write single value file. The default value is "1". The - initial value of the root cgroup is 1, and when a new cgroup is - created, it inherits the current value of its parent. + A read-write single value file. The default value is "1". + Note that this setting is hierarchical, i.e. the writeback would be + implicitly disabled for child cgroups if the upper hierarchy + does so. When this is set to 0, all swapping attempts to swapping devices are disabled. This included both zswap writebacks, and swapping due diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 09126bb8cc9f..1b52b1b7bbc4 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2648,6 +2648,23 @@ Default is Y (on). + kvm.enable_virt_at_load=[KVM,ARM64,LOONGARCH,MIPS,RISCV,X86] + If enabled, KVM will enable virtualization in hardware + when KVM is loaded, and disable virtualization when KVM + is unloaded (if KVM is built as a module). + + If disabled, KVM will dynamically enable and disable + virtualization on-demand when creating and destroying + VMs, i.e. on the 0=>1 and 1=>0 transitions of the + number of VMs. + + Enabling virtualization at module lode avoids potential + latency for creation of the 0=>1 VM, as KVM serializes + virtualization enabling across all online CPUs. The + "cost" of enabling virtualization when KVM is loaded, + is that doing so may interfere with using out-of-tree + hypervisors that want to "own" virtualization hardware. + kvm.enable_vmware_backdoor=[KVM] Support VMware backdoor PV interface. Default is false (don't support). diff --git a/Documentation/arch/riscv/vm-layout.rst b/Documentation/arch/riscv/vm-layout.rst index 077b968dcc81..eabec99b5852 100644 --- a/Documentation/arch/riscv/vm-layout.rst +++ b/Documentation/arch/riscv/vm-layout.rst @@ -134,19 +134,3 @@ RISC-V Linux Kernel SV57 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ - - -Userspace VAs --------------------- -To maintain compatibility with software that relies on the VA space with a -maximum of 48 bits the kernel will, by default, return virtual addresses to -userspace from a 48-bit range (sv48). This default behavior is achieved by -passing 0 into the hint address parameter of mmap. On CPUs with an address space -smaller than sv48, the CPU maximum supported address space will be the default. - -Software can "opt-in" to receiving VAs from another VA space by providing -a hint address to mmap. When a hint address is passed to mmap, the returned -address will never use more bits than the hint address. For example, if a hint -address of `1 << 40` is passed to mmap, a valid returned address will never use -bits 41 through 63. If no mappable addresses are available in that range, mmap -will return `MAP_FAILED`. diff --git a/Documentation/core-api/workqueue.rst b/Documentation/core-api/workqueue.rst index bcc370c876be..16f861c9791e 100644 --- a/Documentation/core-api/workqueue.rst +++ b/Documentation/core-api/workqueue.rst @@ -260,7 +260,7 @@ Some users depend on strict execution ordering where only one work item is in flight at any given time and the work items are processed in queueing order. While the combination of ``@max_active`` of 1 and ``WQ_UNBOUND`` used to achieve this behavior, this is no longer the -case. Use ``alloc_ordered_queue()`` instead. +case. Use alloc_ordered_workqueue() instead. Example Execution Scenarios diff --git a/Documentation/devicetree/bindings/display/panel/wl-355608-a8.yaml b/Documentation/devicetree/bindings/display/panel/anbernic,rg35xx-plus-panel.yaml index e552d01b52b9..1d67492ebd3b 100644 --- a/Documentation/devicetree/bindings/display/panel/wl-355608-a8.yaml +++ b/Documentation/devicetree/bindings/display/panel/anbernic,rg35xx-plus-panel.yaml @@ -1,10 +1,10 @@ # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2 --- -$id: http://devicetree.org/schemas/display/panel/wl-355608-a8.yaml# +$id: http://devicetree.org/schemas/display/panel/anbernic,rg35xx-plus-panel.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# -title: WL-355608-A8 3.5" (640x480 pixels) 24-bit IPS LCD panel +title: Anbernic RG35XX series (WL-355608-A8) 3.5" 640x480 24-bit IPS LCD panel maintainers: - Ryan Walklin <ryan@testtoast.com> @@ -15,7 +15,14 @@ allOf: properties: compatible: - const: wl-355608-a8 + oneOf: + - const: anbernic,rg35xx-plus-panel + - items: + - enum: + - anbernic,rg35xx-2024-panel + - anbernic,rg35xx-h-panel + - anbernic,rg35xx-sp-panel + - const: anbernic,rg35xx-plus-panel reg: maxItems: 1 @@ -40,7 +47,7 @@ examples: #size-cells = <0>; panel@0 { - compatible = "wl-355608-a8"; + compatible = "anbernic,rg35xx-plus-panel"; reg = <0>; spi-3wire; diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.yaml b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.yaml index 379721027bf8..51d48d4130d3 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.yaml +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.yaml @@ -42,6 +42,7 @@ properties: - focaltech,ft5426 - focaltech,ft5452 - focaltech,ft6236 + - focaltech,ft8201 - focaltech,ft8719 reg: diff --git a/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.yaml b/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.yaml index 917c40d5c382..1cbe44ab23b1 100644 --- a/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.yaml +++ b/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.yaml @@ -28,7 +28,7 @@ unevaluatedProperties: false examples: - | - nvmem { + soc-nvmem { compatible = "xlnx,zynqmp-nvmem-fw"; nvmem-layout { compatible = "fixed-layout"; diff --git a/Documentation/devicetree/bindings/usb/microchip,usb2514.yaml b/Documentation/devicetree/bindings/usb/microchip,usb2514.yaml index 245e8c3ce669..b14e6f37b298 100644 --- a/Documentation/devicetree/bindings/usb/microchip,usb2514.yaml +++ b/Documentation/devicetree/bindings/usb/microchip,usb2514.yaml @@ -10,7 +10,7 @@ maintainers: - Fabio Estevam <festevam@gmail.com> allOf: - - $ref: usb-hcd.yaml# + - $ref: usb-device.yaml# properties: compatible: @@ -36,6 +36,13 @@ required: - compatible - reg +patternProperties: + "^.*@[0-9a-f]{1,2}$": + description: The hard wired USB devices + type: object + $ref: /schemas/usb/usb-device.yaml + additionalProperties: true + unevaluatedProperties: false examples: diff --git a/Documentation/filesystems/erofs.rst b/Documentation/filesystems/erofs.rst index cc4626d6ee4f..c293f8e37468 100644 --- a/Documentation/filesystems/erofs.rst +++ b/Documentation/filesystems/erofs.rst @@ -75,7 +75,7 @@ Here are the main features of EROFS: - Support merging tail-end data into a special inode as fragments. - - Support large folios for uncompressed files. + - Support large folios to make use of THPs (Transparent Hugepages); - Support direct I/O on uncompressed files to avoid double caching for loop devices; diff --git a/Documentation/filesystems/smb/ksmbd.rst b/Documentation/filesystems/smb/ksmbd.rst index 6b30e43a0d11..67cb68ea6e68 100644 --- a/Documentation/filesystems/smb/ksmbd.rst +++ b/Documentation/filesystems/smb/ksmbd.rst @@ -13,7 +13,7 @@ KSMBD architecture The subset of performance related operations belong in kernelspace and the other subset which belong to operations which are not really related with performance in userspace. So, DCE/RPC management that has historically resulted -into number of buffer overflow issues and dangerous security bugs and user +into a number of buffer overflow issues and dangerous security bugs and user account management are implemented in user space as ksmbd.mountd. File operations that are related with performance (open/read/write/close etc.) in kernel space (ksmbd). This also allows for easier integration with VFS @@ -24,8 +24,8 @@ ksmbd (kernel daemon) When the server daemon is started, It starts up a forker thread (ksmbd/interface name) at initialization time and open a dedicated port 445 -for listening to SMB requests. Whenever new clients make request, Forker -thread will accept the client connection and fork a new thread for dedicated +for listening to SMB requests. Whenever new clients make a request, the Forker +thread will accept the client connection and fork a new thread for a dedicated communication channel between the client and the server. It allows for parallel processing of SMB requests(commands) from clients as well as allowing for new clients to make new connections. Each instance is named ksmbd/1~n(port number) @@ -34,12 +34,12 @@ thread can decide to pass through the commands to the user space (ksmbd.mountd), currently DCE/RPC commands are identified to be handled through the user space. To further utilize the linux kernel, it has been chosen to process the commands as workitems and to be executed in the handlers of the ksmbd-io kworker threads. -It allows for multiplexing of the handlers as the kernel take care of initiating +It allows for multiplexing of the handlers as the kernel takes care of initiating extra worker threads if the load is increased and vice versa, if the load is -decreased it destroys the extra worker threads. So, after connection is -established with client. Dedicated ksmbd/1..n(port number) takes complete +decreased it destroys the extra worker threads. So, after the connection is +established with the client. Dedicated ksmbd/1..n(port number) takes complete ownership of receiving/parsing of SMB commands. Each received command is worked -in parallel i.e., There can be multiple clients commands which are worked in +in parallel i.e., there can be multiple client commands which are worked in parallel. After receiving each command a separated kernel workitem is prepared for each command which is further queued to be handled by ksmbd-io kworkers. So, each SMB workitem is queued to the kworkers. This allows the benefit of load @@ -49,9 +49,9 @@ performance by handling client commands in parallel. ksmbd.mountd (user space daemon) -------------------------------- -ksmbd.mountd is userspace process to, transfer user account and password that +ksmbd.mountd is a userspace process to, transfer the user account and password that are registered using ksmbd.adduser (part of utils for user space). Further it -allows sharing information parameters that parsed from smb.conf to ksmbd in +allows sharing information parameters that are parsed from smb.conf to ksmbd in kernel. For the execution part it has a daemon which is continuously running and connected to the kernel interface using netlink socket, it waits for the requests (dcerpc and share/user info). It handles RPC calls (at a minimum few @@ -124,7 +124,7 @@ How to run 1. Download ksmbd-tools(https://github.com/cifsd-team/ksmbd-tools/releases) and compile them. - - Refer README(https://github.com/cifsd-team/ksmbd-tools/blob/master/README.md) + - Refer to README(https://github.com/cifsd-team/ksmbd-tools/blob/master/README.md) to know how to use ksmbd.mountd/adduser/addshare/control utils $ ./autogen.sh @@ -133,7 +133,7 @@ How to run 2. Create /usr/local/etc/ksmbd/ksmbd.conf file, add SMB share in ksmbd.conf file. - - Refer ksmbd.conf.example in ksmbd-utils, See ksmbd.conf manpage + - Refer to ksmbd.conf.example in ksmbd-utils, See ksmbd.conf manpage for details to configure shares. $ man ksmbd.conf @@ -145,7 +145,7 @@ How to run $ man ksmbd.adduser $ sudo ksmbd.adduser -a <Enter USERNAME for SMB share access> -4. Insert ksmbd.ko module after build your kernel. No need to load module +4. Insert the ksmbd.ko module after you build your kernel. No need to load the module if ksmbd is built into the kernel. - Set ksmbd in menuconfig(e.g. $ make menuconfig) @@ -175,7 +175,7 @@ Each layer 1. Enable all component prints # sudo ksmbd.control -d "all" -2. Enable one of components (smb, auth, vfs, oplock, ipc, conn, rdma) +2. Enable one of the components (smb, auth, vfs, oplock, ipc, conn, rdma) # sudo ksmbd.control -d "smb" 3. Show what prints are enabled. diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst index bb5c44f8bd1c..6dc66b4f31a7 100644 --- a/Documentation/kbuild/llvm.rst +++ b/Documentation/kbuild/llvm.rst @@ -126,7 +126,7 @@ Ccache ``ccache`` can be used with ``clang`` to improve subsequent builds, (though KBUILD_BUILD_TIMESTAMP_ should be set to a deterministic value between builds -in order to avoid 100% cache misses, see Reproducible_builds_ for more info): +in order to avoid 100% cache misses, see Reproducible_builds_ for more info):: KBUILD_BUILD_TIMESTAMP='' make LLVM=1 CC="ccache clang" diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst index 04f6aa377a5d..8e30c8f7697d 100644 --- a/Documentation/process/coding-style.rst +++ b/Documentation/process/coding-style.rst @@ -629,18 +629,6 @@ The preferred style for long (multi-line) comments is: * with beginning and ending almost-blank lines. */ -For files in net/ and drivers/net/ the preferred style for long (multi-line) -comments is a little different. - -.. code-block:: c - - /* The preferred comment style for files in net/ and drivers/net - * looks like this. - * - * It is nearly the same as the generally preferred comment style, - * but there is no initial almost-blank line. - */ - It's also important to comment data, whether they are basic types or derived types. To this end, use just one data declaration per line (no commas for multiple data declarations). This leaves you room for a small comment on each diff --git a/Documentation/process/maintainer-netdev.rst b/Documentation/process/maintainer-netdev.rst index fe8616397d63..c9edf9e7362d 100644 --- a/Documentation/process/maintainer-netdev.rst +++ b/Documentation/process/maintainer-netdev.rst @@ -355,23 +355,6 @@ just do it. As a result, a sequence of smaller series gets merged quicker and with better review coverage. Re-posting large series also increases the mailing list traffic. -Multi-line comments -~~~~~~~~~~~~~~~~~~~ - -Comment style convention is slightly different for networking and most of -the tree. Instead of this:: - - /* - * foobar blah blah blah - * another line of text - */ - -it is requested that you make it look like this:: - - /* foobar blah blah blah - * another line of text - */ - Local variable ordering ("reverse xmas tree", "RCS") ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -392,6 +375,22 @@ When working in existing code which uses nonstandard formatting make your code follow the most recent guidelines, so that eventually all code in the domain of netdev is in the preferred format. +Using device-managed and cleanup.h constructs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Netdev remains skeptical about promises of all "auto-cleanup" APIs, +including even ``devm_`` helpers, historically. They are not the preferred +style of implementation, merely an acceptable one. + +Use of ``guard()`` is discouraged within any function longer than 20 lines, +``scoped_guard()`` is considered more readable. Using normal lock/unlock is +still (weakly) preferred. + +Low level cleanup constructs (such as ``__free()``) can be used when building +APIs and helpers, especially scoped iterators. However, direct use of +``__free()`` within networking core and drivers is discouraged. +Similar guidance applies to declaring variables mid-function. + Resending after review ~~~~~~~~~~~~~~~~~~~~~~ diff --git a/Documentation/rust/coding-guidelines.rst b/Documentation/rust/coding-guidelines.rst index 05542840b16c..329b070a1d47 100644 --- a/Documentation/rust/coding-guidelines.rst +++ b/Documentation/rust/coding-guidelines.rst @@ -145,32 +145,32 @@ This is how a well-documented Rust function may look like: This example showcases a few ``rustdoc`` features and some conventions followed in the kernel: - - The first paragraph must be a single sentence briefly describing what - the documented item does. Further explanations must go in extra paragraphs. +- The first paragraph must be a single sentence briefly describing what + the documented item does. Further explanations must go in extra paragraphs. - - Unsafe functions must document their safety preconditions under - a ``# Safety`` section. +- Unsafe functions must document their safety preconditions under + a ``# Safety`` section. - - While not shown here, if a function may panic, the conditions under which - that happens must be described under a ``# Panics`` section. +- While not shown here, if a function may panic, the conditions under which + that happens must be described under a ``# Panics`` section. - Please note that panicking should be very rare and used only with a good - reason. In almost all cases, a fallible approach should be used, typically - returning a ``Result``. + Please note that panicking should be very rare and used only with a good + reason. In almost all cases, a fallible approach should be used, typically + returning a ``Result``. - - If providing examples of usage would help readers, they must be written in - a section called ``# Examples``. +- If providing examples of usage would help readers, they must be written in + a section called ``# Examples``. - - Rust items (functions, types, constants...) must be linked appropriately - (``rustdoc`` will create a link automatically). +- Rust items (functions, types, constants...) must be linked appropriately + (``rustdoc`` will create a link automatically). - - Any ``unsafe`` block must be preceded by a ``// SAFETY:`` comment - describing why the code inside is sound. +- Any ``unsafe`` block must be preceded by a ``// SAFETY:`` comment + describing why the code inside is sound. - While sometimes the reason might look trivial and therefore unneeded, - writing these comments is not just a good way of documenting what has been - taken into account, but most importantly, it provides a way to know that - there are no *extra* implicit constraints. + While sometimes the reason might look trivial and therefore unneeded, + writing these comments is not just a good way of documenting what has been + taken into account, but most importantly, it provides a way to know that + there are no *extra* implicit constraints. To learn more about how to write documentation for Rust and extra features, please take a look at the ``rustdoc`` book at: diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst index d06a36106cd4..8e3ad9678719 100644 --- a/Documentation/rust/quick-start.rst +++ b/Documentation/rust/quick-start.rst @@ -305,7 +305,7 @@ If GDB/Binutils is used and Rust symbols are not getting demangled, the reason is the toolchain does not support Rust's new v0 mangling scheme yet. There are a few ways out: - - Install a newer release (GDB >= 10.2, Binutils >= 2.36). +- Install a newer release (GDB >= 10.2, Binutils >= 2.36). - - Some versions of GDB (e.g. vanilla GDB 10.1) are able to use - the pre-demangled names embedded in the debug info (``CONFIG_DEBUG_INFO``). +- Some versions of GDB (e.g. vanilla GDB 10.1) are able to use + the pre-demangled names embedded in the debug info (``CONFIG_DEBUG_INFO``). diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index a4b7dc4a9dda..e32471977d0a 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8097,6 +8097,14 @@ KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS By default, KVM emulates MONITOR/MWAIT (if guest CPUID on writes to MISC_ENABLE if KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT is disabled. + +KVM_X86_QUIRK_SLOT_ZAP_ALL By default, KVM invalidates all SPTEs in + fast way for memslot deletion when VM type + is KVM_X86_DEFAULT_VM. + When this quirk is disabled or when VM type + is other than KVM_X86_DEFAULT_VM, KVM zaps + only leaf SPTEs that are within the range of + the memslot being deleted. =================================== ============================================ 7.32 KVM_CAP_MAX_VCPU_ID diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 02880d5552d5..be3c323888b1 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -11,6 +11,8 @@ The acquisition orders for mutexes are as follows: - cpus_read_lock() is taken outside kvm_lock +- kvm_usage_lock is taken outside cpus_read_lock() + - kvm->lock is taken outside vcpu->mutex - kvm->lock is taken outside kvm->slots_lock and kvm->irq_lock @@ -24,6 +26,12 @@ The acquisition orders for mutexes are as follows: are taken on the waiting side when modifying memslots, so MMU notifiers must not take either kvm->slots_lock or kvm->slots_arch_lock. +cpus_read_lock() vs kvm_lock: +- Taking cpus_read_lock() outside of kvm_lock is problematic, despite that + being the official ordering, as it is quite easy to unknowingly trigger + cpus_read_lock() while holding kvm_lock. Use caution when walking vm_list, + e.g. avoid complex operations when possible. + For SRCU: - ``synchronize_srcu(&kvm->srcu)`` is called inside critical sections @@ -227,10 +235,16 @@ time it will be set using the Dirty tracking mechanism described above. :Type: mutex :Arch: any :Protects: - vm_list - - kvm_usage_count + +``kvm_usage_lock`` +^^^^^^^^^^^^^^^^^^ + +:Type: mutex +:Arch: any +:Protects: - kvm_usage_count - hardware virtualization enable/disable -:Comment: KVM also disables CPU hotplug via cpus_read_lock() during - enable/disable. +:Comment: Exists to allow taking cpus_read_lock() while kvm_usage_count is + protected, which simplifies the virtualization enabling logic. ``kvm->mn_invalidate_lock`` ^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -290,11 +304,12 @@ time it will be set using the Dirty tracking mechanism described above. wakeup. ``vendor_module_lock`` -^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +^^^^^^^^^^^^^^^^^^^^^^ :Type: mutex :Arch: x86 :Protects: loading a vendor module (kvm_amd or kvm_intel) -:Comment: Exists because using kvm_lock leads to deadlock. cpu_hotplug_lock is - taken outside of kvm_lock, e.g. in KVM's CPU online/offline callbacks, and - many operations need to take cpu_hotplug_lock when loading a vendor module, - e.g. updating static calls. +:Comment: Exists because using kvm_lock leads to deadlock. kvm_lock is taken + in notifiers, e.g. __kvmclock_cpufreq_notifier(), that may be invoked while + cpu_hotplug_lock is held, e.g. from cpufreq_boost_trigger_state(), and many + operations need to take cpu_hotplug_lock when loading a vendor module, e.g. + updating static calls. |