Softoff features in PLDM lib.

[Brad Bishop]

> On Oct 9, 2021, at 7:47 AM, Thu Nguyen <thu at amperemail.onmicrosoft.com> wrote:
> 
> Dear Chicago Duan and George Liu,
> 
> 
> In PLDM source, I saw that Inspur supported graceful shutdown the host OS thru PLDM commands.
> 
> https://github.com/openbmc/pldm/commit/184f60263a0e4c3dda934d94ecb2a904ef835299#diff-59fd39a9594f6d6f82af25037f211858fafa418aacc055e85b4cc29abccf9dee
> 
> The feature used PLDM Platform SetEffecterState command to request the host OS shutdown.
> 
> I wonder which part in the host software will response for this PLDM request?
> 
> Does the host OS ( Centos, Ubuntu...) directly handle this type of command?
> 
> 
> Thanks.
> 
> Thu Nguyen.

Some POWER architecture servers run a type one hypervisor called PowerVM.  This is the only operating system I’m aware of that has a PLDM implementation.  If anyone watching is aware of any others please correct me.

The BMC code you reference was written specifically with PowerVM in mind.  In theory any software running on the host processor _could_ implement mctp & plum and support this effector but I honestly don’t ever see that happening in say, Windows or a typical Linux distribution (Centos, Ubuntu...).

How did you implement soft-off-via-bmc before OpenBMC?

I’d be curious to know how this soft-off-via-bmc functionality is typically implemented in x86 or arm based server designs with arbitrary operating systems.

thx - brad