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-bus-siox | 90 ++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-siox (limited to 'Documentation/ABI/testing/sysfs-bus-siox') diff --git a/Documentation/ABI/testing/sysfs-bus-siox b/Documentation/ABI/testing/sysfs-bus-siox new file mode 100644 index 000000000..50e80238f --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-siox @@ -0,0 +1,90 @@ +What: /sys/bus/siox/devices/siox-X/active +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + On reading represents the current state of the bus. If it + contains a "0" the bus is stopped and connected devices are + expected to not do anything because their watchdog triggered. + When the file contains a "1" the bus is operated and periodically + does a push-pull cycle to write and read data from the + connected devices. + + When writing a "0" or "1" the bus moves to the described state. + +What: /sys/bus/siox/devices/siox-X/device_add +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Write-only file. Write + + + + to add a new device dynamically. is the name that is used to match + to a driver (similar to the platform bus). and define + the length of the input and output shift register in bytes respectively. + + defines the 4 bit device type that is check to identify connection + problems. + + The new device is added to the end of the existing chain. + +What: /sys/bus/siox/devices/siox-X/device_remove +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Write-only file. A single write removes the last device in the siox chain. + +What: /sys/bus/siox/devices/siox-X/poll_interval_ns +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Defines the interval between two poll cycles in nano seconds. + Note this is rounded to jiffies on writing. On reading the current value + is returned. + +What: /sys/bus/siox/devices/siox-X-Y/connected +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value. "0" means the Yth device on siox bus X isn't "connected" i.e. + communication with it is not ensured. "1" signals a working connection. + +What: /sys/bus/siox/devices/siox-X-Y/inbytes +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the inbytes value provided to siox-X/device_add + +What: /sys/bus/siox/devices/siox-X-Y/status_errors +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Counts the number of time intervals when the read status byte doesn't yield the + expected value. + +What: /sys/bus/siox/devices/siox-X-Y/type +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the type value provided to siox-X/device_add. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting if the watchdog of the siox device is + active. "0" means the watchdog is not active and the device is expected to + be operational. "1" means the watchdog keeps the device in reset. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog_errors +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the number to time intervals when the + watchdog was active. + +What: /sys/bus/siox/devices/siox-X-Y/outbytes +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the outbytes value provided to siox-X/device_add. -- cgit v1.3.1