[Fw_Os_Forum] Support for EFI MP Services

Tue Jul 19 10:51:11 EDT 2016

Acan,
Yes. The PI MP Service Protocol is the one I was using originally, but
I did find the EFI_MP_SERVICES_PROTOCOL you mentioned. Unfortunately,
BS->LocateProtocol returns EFI_NOT_FOUND for that one as well;
however, I'm running under VMware ESXi, and I'm wondering whether the
lack of support could be due to ESXi's incomplete implementation of
the UEFI spec. Do modern desktop systems typically support this
protocol?
Question: Is support for EFI_MP_SERVICES_PROTOCOL mandatory for
firmware that claims to support certain versions of the UEFI spec, or
is it always optional?

Thanks,
Brett S.

On Mon, Jul 18, 2016 at 9:31 PM, Chen, Ming (Acan, DTD-SH)
<ming.chen at hp.com> wrote:
> Hi Brett,
>
> So the MP Service Protocol you have tried to locate is the (PI) MP Service Protocol, {0x3fdda605, 0xa76e, 0x4f46, {0xad, 0x29, 0x12, 0xf4, 0x53, 0x1b, 0x3d, 0x08}?
>
> From my understanding, the Framework MP Service Protocol should only exist in old systems. Below wiki have the GUID and interface definitions:
> http://wiki.phoenix.com/wiki/index.php/EFI_MP_SERVICES_PROTOCOL
>
>
> Thanks,
> Acan
>
> -----Original Message-----
> From: Brett Stahlman [mailto:brettstahlman at gmail.com]
> Sent: Monday, July 18, 2016 10:16 PM
> To: Chen, Ming (Acan, DTD-SH) <ming.chen at hp.com>
> Cc: fw_os_forum at mailman.uefi.org
> Subject: Re: [Fw_Os_Forum] Support for EFI MP Services
>
> Acan,
> Can you point me to the GUID for the Framework MP Service Protocol? So far, I've seen only this one:
>
> #define EFI_MP_SERVICES_PPI_GUID \
> {0xee16160a, 0xe8be, 0x47a6,\
> {0x82, 0xa, 0xc6, 0x90, 0xd, 0xb0, 0x25, 0xa } }
>
> Thanks,
> Brett S.
>
> On Sun, Jul 17, 2016 at 8:34 PM, Chen, Ming (Acan, DTD-SH) <ming.chen at hp.com> wrote:
>> Hi Brett,
>>
>> Just mention that there are two MP Service protocols: Framework MP Service Protocol, and (PI) MP Service Protocol.
>> Note sure if you have tried both when you BS->LocateProtocol()?
>>
>>
>> Thanks,
>> Acan
>>
>> -----Original Message-----
>> From: fw_os_forum-bounces at mailman.uefi.org
>> [mailto:fw_os_forum-bounces at mailman.uefi.org] On Behalf Of Brett
>> Stahlman
>> Sent: Saturday, July 16, 2016 3:27 AM
>> To: fw_os_forum at mailman.uefi.org
>> Subject: Re: [Fw_Os_Forum] Support for EFI MP Services
>>
>> Aaron,
>> So methods like GetNumberOfProcessors and StartupAllAPs (documented
>> here
>> http://www.uefi.org/sites/default/files/resources/Plugfest_Multiproces
>> sing-with_UEFI-McDaniel.pdf) are not meant to be called from a boot
>> loader using Boot Services?
>>
>> I will have a look at the other references. Hopefully the firmware's AP initialization obviates the need for some of the tedious, low-level real mode trampoline code I've seen in the kernel and other loader code performing AP bring up... If UEFI simplifies only the BSP side of things, it doesn't seem a very complete solution...
>>
>> Thanks,
>> Brett S.
>>
>> On Fri, Jul 15, 2016 at 11:28 AM,  <Aaron.Pop at congatec.com> wrote:
>>> Hi Brett,
>>>
>>>>>1. Is there a way to add support for MP Services to firmware that
>>>>>doesn't  have it natively? Is there a list somewhere documenting
>>>>>which firmware  supports?
>>> If you platform doesn't support the MP services protocol, chances are
>>> that your platform is not compliant with the Platform Initialization
>>> specification.  Additionally, the PI specification defines protocols
>>> that are intended for use by the firmware, not by boot loaders or the
>>> OS. I would highly recommend that your boot loader only use protocols
>>> that are defined in the UEFI specification.
>>
>>
>>>
>>>>>2. What is the best way to bring up the APs in an environment that
>>>>>doesn't  support the MP Services Protocol? I've read something that
>>>>>suggests it might  be easier with UEFI than with BIOS because the PI
>>>>>firmware does some  pre-initialization of the APs even before
>>>>>handoff to the BSP - but I haven't  found much documentation on this...
>>> X86/X86_64 operating systems follow intel's multi processor
>>> specification for waking APs when they are given control.
>>> (http://download.intel.com/design/archives/processors/pro/docs/242016
>>> 0
>>> 6.pdf) All firmware (even legacy BIOSes) would initialize all
>>> processors in the system, and then would either halt the APs, or put
>>> the APs into a spin loop and only leave the BSP (boot strap
>>> processor) running when giving control to a bootloader.
>>>
>>> For more information, you can refer to
>>> http://wiki.osdev.org/Symmetric_Multiprocessing, or you can check out
>>> how the linux kernel performs multi processor bring up.
>>>
>>> -Aaron
>>>
>>>
>>>
>>>
>>>
>>>
>>> From:        Brett Stahlman <brettstahlman at gmail.com>
>>> To:        fw_os_forum at mailman.uefi.org
>>> Date:        07/15/2016 09:11 AM
>>> Subject:        [Fw_Os_Forum] Support for EFI MP Services
>>> Sent by:        fw_os_forum-bounces at mailman.uefi.org
>>> ________________________________
>>>
>>>
>>>
>>> I'm working on an x86_64 UEFI boot loader that runs on the BSP in
>>> 64-bit long mode, and must bring up APs (secondary processors) after
>>> some preliminary initialization. I've seen some documentation on EFI
>>> MP (multi-processor) Service Protocol, but the headers in gnu-efi
>>> don't appear to support it, and BS->LocateProtocol() reports status
>>> 14 (EFI_NOT_FOUND). My questions are...
>>>
>>> 1. Is there a way to add support for MP Services to firmware that
>>> doesn't have it natively? Is there a list somewhere documenting which
>>> firmware supports?
>>> 2. What is the best way to bring up the APs in an environment that
>>> doesn't support the MP Services Protocol? I've read something that
>>> suggests it might be easier with UEFI than with BIOS because the PI
>>> firmware does some pre-initialization of the APs even before handoff
>>> to the BSP - but I haven't found much documentation on this...
>>>
>>> Any help would be greatly appreciated.
>>> Thanks,
>>> Brett S.
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