Out-of-band SRESET
Hi,
One requirement from a OpenPOWER service point-of-view is to be able to trigger an out-of-band SRESET on a unresponsive system. We can then have the necessary plumbing in the host Linux kernel to either drop the machine into a debugger or trigger a dump capture, if configured.
On P9, this would translate to a series of SCOM operations for the SBE It would be good to have a REST API defined to cater to this specific purpose.
The API should cater to:
- SRESET a core
- SRESET a chip
- SRESET all cores
Thoughts?
Regards,
Ananth
Quoted 16 lines · Ananth N Mavinakayanahalli
Hi,
One requirement from a OpenPOWER service point-of-view is to be able to trigger an out-of-band SRESET on a unresponsive system. We can then have the necessary plumbing in the host Linux kernel to either drop the machine into a debugger or trigger a dump capture, if configured.
On P9, this would translate to a series of SCOM operations for the SBE It would be good to have a REST API defined to cater to this specific purpose.
The API should cater to:
- SRESET a core
- SRESET a chip
- SRESET all cores
Quoted 5 lines
Thoughts?
Regards,
Ananth
Ananth,
I understand the desire from your end with respect to debugging the host. Is there something we can do to model this better from a REST perspective to make this less Power-specific? Do other architectures also have a "send debug interrupt"?
Do you need to SRESET targeting an SMT thread? We will need to come up with some kind of identifier for sending the debug interrupts.
Signature · 1 line
Patrick Williams
I know x86 has debug modes but I'm unfamiliar with them. I'll ask my teammates who know more for some details to see if and how the BMC is involved.
Quoted 35 lines · Patrick Williams
Quoted 16 lines · Ananth N Mavinakayanahalli
Hi,
One requirement from a OpenPOWER service point-of-view is to be able to trigger an out-of-band SRESET on a unresponsive system. We can then have the necessary plumbing in the host Linux kernel to either drop the machine into a debugger or trigger a dump capture, if configured.
On P9, this would translate to a series of SCOM operations for the SBE It would be good to have a REST API defined to cater to this specific purpose.
The API should cater to:
- SRESET a core
- SRESET a chip
- SRESET all coresQuoted 5 lines
Thoughts?
Regards,
AnanthAnanth,
I understand the desire from your end with respect to debugging the host. Is there something we can do to model this better from a REST perspective to make this less Power-specific? Do other architectures also have a "send debug interrupt"?
Do you need to SRESET targeting an SMT thread? We will need to come up with some kind of identifier for sending the debug interrupts.
--
Patrick Williams
Quoted 23 lines · Patrick Williams
Quoted 16 lines · Ananth N Mavinakayanahalli
Hi,
One requirement from a OpenPOWER service point-of-view is to be able to trigger an out-of-band SRESET on a unresponsive system. We can then have the necessary plumbing in the host Linux kernel to either drop the machine into a debugger or trigger a dump capture, if configured.
On P9, this would translate to a series of SCOM operations for the SBE It would be good to have a REST API defined to cater to this specific purpose.
The API should cater to:
- SRESET a core
- SRESET a chip
- SRESET all coresQuoted 5 lines
Thoughts?
Regards,
Ananth
Quoted 6 lines
Ananth,
I understand the desire from your end with respect to debugging the host. Is there something we can do to model this better from a REST perspective to make this less Power-specific? Do other architectures also have a "send debug interrupt"?
on x86 there's the NMI, which can be sent via "ipmitool power diag"
It also exists in RedFish as a type of restart (on, forceoff, gracefulrestart, nmi etc)
Signature · 2 lines
Stewart Smith OPAL Architect, IBM.
Quoted 23 lines · Patrick Williams
Quoted 16 lines · Ananth N Mavinakayanahalli
Hi,
One requirement from a OpenPOWER service point-of-view is to be able to trigger an out-of-band SRESET on a unresponsive system. We can then have the necessary plumbing in the host Linux kernel to either drop the machine into a debugger or trigger a dump capture, if configured.
On P9, this would translate to a series of SCOM operations for the SBE It would be good to have a REST API defined to cater to this specific purpose.
The API should cater to:
- SRESET a core
- SRESET a chip
- SRESET all coresQuoted 5 lines
Thoughts?
Regards,
Ananth
Quoted 6 lines
Ananth,
I understand the desire from your end with respect to debugging the host. Is there something we can do to model this better from a REST perspective to make this less Power-specific? Do other architectures also have a "send debug interrupt"?
Any option that says nmi for x86 can apply here, IMO.
Quoted 2 lines
Do you need to SRESET targeting an SMT thread? We will need to come up with some kind of identifier for sending the debug interrupts.
For starters, we will be using the SRESET as an unrecoverable entity -- option of last resort. The SRESET all cores will be the most used, but I can envisage cases where we would need specific cores/threads to be forced into xmon or such. While it is good to have the design to be able to accommodate it, targeted SMT thread reset isn't a 'must have' to begin with.
Ananth