From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- Documentation/ABI/testing/sysfs-class-devlink | 130 ++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devlink (limited to 'Documentation/ABI/testing/sysfs-class-devlink') diff --git a/Documentation/ABI/testing/sysfs-class-devlink b/Documentation/ABI/testing/sysfs-class-devlink new file mode 100644 index 000000000..8a21ce515 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-devlink @@ -0,0 +1,130 @@ +What: /sys/class/devlink/.../ +Date: May 2020 +Contact: Saravana Kannan +Description: + Provide a place in sysfs for the device link objects in the + kernel at any given time. The name of a device link directory, + denoted as ... above, is of the form -- + where is the supplier bus:device name and + is the consumer bus:device name. + +What: /sys/class/devlink/.../auto_remove_on +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link will ever be + automatically removed by the driver core when the consumer and + supplier devices themselves are still present. + + This will be one of the following strings: + + - 'consumer unbind' + - 'supplier unbind' + - 'never' + + 'consumer unbind' means the device link will be removed when + the consumer's driver is unbound from the consumer device. + + 'supplier unbind' means the device link will be removed when + the supplier's driver is unbound from the supplier device. + + 'never' means the device link will not be automatically removed + when as long as the supplier and consumer devices themselves + are still present. + +What: /sys/class/devlink/.../consumer +Date: May 2020 +Contact: Saravana Kannan +Description: + This file is a symlink to the consumer device's sysfs directory. + +What: /sys/class/devlink/.../runtime_pm +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link has any impact on the + runtime power management behavior of the consumer and supplier + devices. For example: Making sure the supplier doesn't enter + runtime suspend while the consumer is active. + + This will be one of the following strings: + + === ======================================== + '0' Does not affect runtime power management + '1' Affects runtime power management + === ======================================== + +What: /sys/class/devlink/.../status +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates the status of the device link. The status + of a device link is affected by whether the supplier and + consumer devices have been bound to their corresponding + drivers. The status of a device link also affects the binding + and unbinding of the supplier and consumer devices with their + drivers and also affects whether the software state of the + supplier device is synced with the hardware state of the + supplier device after boot up. + See also: sysfs-devices-state_synced. + + This will be one of the following strings: + + - 'not tracked' + - 'dormant' + - 'available' + - 'consumer probing' + - 'active' + - 'supplier unbinding' + - 'unknown' + + 'not tracked' means this device link does not track the status + and has no impact on the binding, unbinding and syncing the + hardware and software device state. + + 'dormant' means the supplier and the consumer devices have not + bound to their driver. + + 'available' means the supplier has bound to its driver and is + available to supply resources to the consumer device. + + 'consumer probing' means the consumer device is currently + trying to bind to its driver. + + 'active' means the supplier and consumer devices have both + bound successfully to their drivers. + + 'supplier unbinding' means the supplier devices is currently in + the process of unbinding from its driver. + + 'unknown' means the state of the device link is not any of the + above. If this is ever the value, there's a bug in the kernel. + +What: /sys/class/devlink/.../supplier +Date: May 2020 +Contact: Saravana Kannan +Description: + This file is a symlink to the supplier device's sysfs directory. + +What: /sys/class/devlink/.../sync_state_only +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link is limited to only + affecting the syncing of the hardware and software state of the + supplier device. + + This will be one of the following strings: + + === ================================ + '0' + '1' Affects runtime power management + === ================================ + + '0' means the device link can affect other device behaviors + like binding/unbinding, suspend/resume, runtime power + management, etc. + + '1' means the device link will only affect the syncing of + hardware and software state of the supplier device after boot + up and doesn't not affect other behaviors of the devices. -- cgit v1.3.1