Hi, > > SEV hardware does not have a concept of the metadata. To boot SEV guest we > > need to pass some information to VMM and in past those information were > > passed through SNP_BOOT_BLOCK (GUIDed structure) but Gerd recommended > > that it will be good idea if both SEV and TDX uses a common metadata > > approach > > to pass these information. I personally think it was a good suggestion. So, > > in SNP > > series I went ahead and created a generic metadata structure and hope that > > TDX will build on it. The user of the metadata structure is VMM (qemu, etc); > > while launching the guest the VMM knows whether its creating the SEV or TDX > > guest and will process the entries accordingly. > > > > As per the number of fields in the metadata is concerns, I felt 3 fields > > (start, size > > and type) should be good enough for all the cases. There was a question from > > Gerd to Min asking why do you need the dataoffset/rawdatasize etc and I > > don't > > remember seeing the answer for it. > > The discussion is in this link. https://edk2.groups.io/g/devel/message/80289
The question why TDX_BFV_RAW_DATA_OFFSET and TDX_BFV_RAW_DATA_SIZE are needed and why TDX_BFV_MEMORY_BASE + TDX_BFV_MEMORY_SIZE can't be used is still open. While being at it: The question why "config-b" with a completely different initialization code path is needed is still open too. The tdvf design guide is not helpful here. Although explains what is different in "config-a" vs. "config-b" it does not explain the background, i.e. why some features are supported by "config-b" only. And I guess these two questions are related. With "config-a" there is a fixed offset between TDX_BFV_RAW_DATA_OFFSET + TDX_BFV_MEMORY_BASE, so if you know one of them you can easily calculate the other. With "config-b" this is possibly not the case. So, can you please shed some light on this? thanks, Gerd -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#81063): https://edk2.groups.io/g/devel/message/81063 Mute This Topic: https://groups.io/mt/85761661/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
