From c745cfb27ae3eec2d16e1f8643338f2067d4fef8 Mon Sep 17 00:00:00 2001 From: Moshe Shemesh Date: Tue, 14 Feb 2023 18:38:05 +0200 Subject: [PATCH] devlink: Update devlink health documentation Update devlink-health.rst file: - Add devlink formatted message (fmsg) API documentation. - Add auto-dump as a condition to do dump once error reported. - Expand OOB to clarify this acronym. Signed-off-by: Moshe Shemesh Reviewed-by: Jiri Pirko Reviewed-by: Jakub Kicinski Signed-off-by: Jakub Kicinski --- .../networking/devlink/devlink-health.rst | 23 +++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/devlink/devlink-health.rst b/Documentation/networking/devlink/devlink-health.rst index e37f77734b5b..e0b8cfed610a 100644 --- a/Documentation/networking/devlink/devlink-health.rst +++ b/Documentation/networking/devlink/devlink-health.rst @@ -33,7 +33,7 @@ Device driver can provide specific callbacks for each "health reporter", e.g.: * Recovery procedures * Diagnostics procedures * Object dump procedures - * OOB initial parameters + * Out Of Box initial parameters Different parts of the driver can register different types of health reporters with different handlers. @@ -46,12 +46,31 @@ Once an error is reported, devlink health will perform the following actions: * A log is being send to the kernel trace events buffer * Health status and statistics are being updated for the reporter instance * Object dump is being taken and saved at the reporter instance (as long as - there is no other dump which is already stored) + auto-dump is set and there is no other dump which is already stored) * Auto recovery attempt is being done. Depends on: - Auto-recovery configuration - Grace period vs. time passed since last recover +Devlink formatted message +========================= + +To handle devlink health diagnose and health dump requests, devlink creates a +formatted message structure ``devlink_fmsg`` and send it to the driver's callback +to fill the data in using the devlink fmsg API. + +Devlink fmsg is a mechanism to pass descriptors between drivers and devlink, in +json-like format. The API allows the driver to add nested attributes such as +object, object pair and value array, in addition to attributes such as name and +value. + +Driver should use this API to fill the fmsg context in a format which will be +translated by the devlink to the netlink message later. When it needs to send +the data using SKBs to the netlink layer, it fragments the data between +different SKBs. In order to do this fragmentation, it uses virtual nests +attributes, to avoid actual nesting use which cannot be divided between +different SKBs. + User Interface ==============