Is there any feedback from CXL stakeholders? It is OK if more time is needed to check with CXL stakeholders. But looks like we all agree that the GCD attribute conversion table shall be updated to convert EFI_RESOURCE_ATTRIBUTE_SPECIAL_PURPOSE to EFI_MEMORY_SP. So could we review and merge the conversion table update first, while we are waiting for the feedback from CXL stakeholders? If you agree, a pull request has been created for the conversion table update: https://github.com/tianocore/edk2/pull/5691.
BRs, Lin, Du -----Original Message----- From: Oliver Smith-Denny <o...@linux.microsoft.com> Sent: Friday, May 24, 2024 5:05 AM To: devel@edk2.groups.io; Lin, Du <du....@intel.com>; mikub...@linux.microsoft.com Cc: Liming Gao <gaolim...@byosoft.com.cn>; Kinney, Michael D <michael.d.kin...@intel.com>; Ni, Ray <ray...@intel.com> Subject: Re: [edk2-devel] [PATCH v3 1/1] MdeModulePkg: Add the EFI_RESOURCE_ATTRIBUTE_SPECIAL_PURPOSE attribute On 5/23/2024 2:17 AM, Du Lin wrote: > Thanks for the quick response. > > Agree that the PI and UEFI specs are vague on SP. That is also why I opted to > minimize code changes to DXE core for SP support in patch > https://edk2.groups.io/g/devel/message/118712. > > Would it make more sense to let the caller determine if SP memory is > available for UEFI via EFI resource types (e.g., EFI_RESOURCE_SYSTEM_MEMORY > vs EFI_RESOURCE_MEMORY_RESERVED)? > > CDAT can be read in PEI phase via DOE method and CDAT is important to support > CXL 2.0. I believe CDAT spec is referencing EFI_MEMORY_TYPE and Memory > Attributes defined in UEFI spec section 7.2. "EfiConventionalMemory Type with > EFI_MEMORY_SP Attribute" may suggest that the memory type shall be > EfiConventionalMemory and the attribute shall have SP set when reporting the > memory to OS. And the concern is whether this combination can still be > supported if we always mark resource HOBs with SP set as > EfiGcdMemoryTypeReserved. Thanks for the clarification. I agree that it makes sense to let the resource HOB creator determine whether UEFI will put this in system memory or reserved memory. DxeCore at that point could decide to not allocate any memory with the EFI_MEMORY_SP attribute (or it could decide it doesn't care). We are meeting with some CXL stakeholders to make sure there is no concern with changing this patch and then we will respin this. Thanks, Oliver -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#119402): https://edk2.groups.io/g/devel/message/119402 Mute This Topic: https://groups.io/mt/106165072/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
