From 06f45fe96fcd81531b0bcb2a6115da563ae6dbd6 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 19 Feb 2021 16:40:28 +0100 Subject: xen/events: add per-xenbus device event statistics and settings Add syfs nodes for each xenbus device showing event statistics (number of events and spurious events, number of associated event channels) and for setting a spurious event threshold in case a frontend is sending too many events without being rogue on purpose. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210219154030.10892-7-jgross@suse.com Signed-off-by: Boris Ostrovsky --- Documentation/ABI/testing/sysfs-devices-xenbus | 41 ++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-xenbus (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-devices-xenbus b/Documentation/ABI/testing/sysfs-devices-xenbus new file mode 100644 index 000000000000..fd796cb4f315 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-xenbus @@ -0,0 +1,41 @@ +What: /sys/devices/*/xenbus/event_channels +Date: February 2021 +Contact: Xen Developers mailing list +Description: + Number of Xen event channels associated with a kernel based + paravirtualized device frontend or backend. + +What: /sys/devices/*/xenbus/events +Date: February 2021 +Contact: Xen Developers mailing list +Description: + Total number of Xen events received for a Xen pv device + frontend or backend. + +What: /sys/devices/*/xenbus/jiffies_eoi_delayed +Date: February 2021 +Contact: Xen Developers mailing list +Description: + Summed up time in jiffies the EOI of an interrupt for a Xen + pv device has been delayed in order to avoid stalls due to + event storms. This value rising is a first sign for a rogue + other end of the pv device. + +What: /sys/devices/*/xenbus/spurious_events +Date: February 2021 +Contact: Xen Developers mailing list +Description: + Number of events received for a Xen pv device which did not + require any action. Too many spurious events in a row will + trigger delayed EOI processing. + +What: /sys/devices/*/xenbus/spurious_threshold +Date: February 2021 +Contact: Xen Developers mailing list +Description: + Controls the tolerated number of subsequent spurious events + before delayed EOI processing is triggered for a Xen pv + device. Default is 1. This can be modified in case the other + end of the pv device is issuing spurious events on a regular + basis and is known not to be malicious on purpose. Raising + the value for such cases can improve pv device performance. -- cgit v1.2.3