<div dir="ltr"><div dir="ltr">## Problem Description<br>Issue #457: Add support to debug unresponsive host.<br><br>Scope: High level design direction to solve this problem, <br><br>## Background and References<br>There are situation at customer places where OPAL/Linux goes unresponsive causing a system hang. And there is no way to figure out what went wrong with Linux kernel or OPAL. Looking for a way to trigger a dump capture on Linux host so that we can capture the OS dump for post analysis.<br><br>## Proposed Design for POWER processor based systems:<br>Get all Host CPUs in reset vector and Linux then has a mechanism to patch it into panic-kdump path to trigger dump capture. This will enable us to analyze and fix customer issue where we see Linux hang and unresponsive system.<br><br>### Redfish Schema used:<br>* Reference: DSP2046 2018.3,<br>* ComputerSystem 1.6.0 schema provides an action called #ComputerSystem.Resetâ€, This action is used to reset the system. ResetType parameter is used for indicating type of reset need to be performed. In this use case we can use “Nmi†type <br>   * Nmi: Generate a Diagnostic Interrupt (usually an NMI on x86 systems) to cease normal operations, perform diagnostic actions and typically halt the system. 
<br>* ### d-bus :<br><br>Option 1:  Extending the existing d-bus interface state.Host name space ( /openbmc/phosphor-dbus-interfaces/xyz/openbmc_project/State/Host.interface.yaml ) to support new RequestedHostTransition property called “Nmiâ€.  d-bus backend can internally invoke processor specific target to do Sreset( equivalent to x86 NMI) and associated actions.<br><br>Option 2: Introducing new d-bus interface in the control.state namespace ( /openbmc/phosphor-dbus-interfaces/xyz/openbmc_project/Control/Host/NMI.interface.yaml) namespace and implement the new d-bus back-end for respective processor specific targets.<br><br>## Alternatives Considered<br>NA<br><br>## Impacts:<br>NA<br><br>## Testing<br>NA<br><br>Looking for input from the team on this High level design direction approach.<br><br></div></div>