Re: [PATCH V8 3/3] OvmfPkg: Enable TDX in ResetVector

["Min Xu" <min.m.xu@intel.com>]

On September 27, 2021 4:43 PM, Gerd Hoffmann wrote:
>   Hi,
> 
> > +_Bfv:
> > +  DD TDX_BFV_RAW_DATA_OFFSET
> > +  DD TDX_BFV_RAW_DATA_SIZE
> > +  DQ TDX_BFV_MEMORY_BASE
> > +  DQ TDX_BFV_MEMORY_SIZE
> > +  DD TDX_METADATA_SECTION_TYPE_BFV
> > +  DD TDX_METADATA_ATTRIBUTES_EXTENDMR
> 
> Size is still added twice, doesn't make sense given that they are either equal
> or RAW_DATA_SIZE is zero.  One size field being 32bit and the other being
> 64bit is pointless too (see also my mail to Jiewen).
>
Gerd, I would like to hold on until Jiewen and you reach consensus. Thanks for your understanding.
> 
> > +  DD TDX_METADATA_SECTION_TYPE_TEMP_MEM
> 
> There are a bunch of TEMP_MEM entries, some of them are next to each
> other in MEMFD, so you can squash them into one entry.

Below is the layout of MEMFD (Used by TDX)
I will squash the TEMP_MEM entries into one entry if they're adjacent. For example,  Mailbox + WorkArea will be squash into one entry.
But the Heap/Stack cannot be squashed with Mailbox/Workarea, because there is a memory hole (0xD000 - 0x10000) between these 2 entry.

+------------------------------------------------+  0x20000
|                                                                 |
|      PcdOvmfSecPeiTempRam             | * Tdx Heap/Stack (Mem)*
|                                                                 |
+------------------------------------------------+ 0x10000
|                                                                 |
+------------------------------------------------+0xD000
|     PcdOvmfSecGhcbBackupBase       |  *Tdx Mailbox (Mem)*
+------------------------------------------------+0xC000
|    PcdOvmWorkArea                            |  *WorkArea (Mem)*
+------------------------------------------------+0xB000
|    PcdOvmfSecGhcb                              | *TdHob  (HOB)*
+------------------------------------------------+0x9000
|    PcdOvmfSecGhcbPageTable            |
|    PcdGuidedExtractHandlerTable      |
|    PcdOvmfLockBoxStorage                 |
+------------------------------------------------+ 0x6000
|                                                                 |
|    PcdOvmfSecPageTables                   |  *PageTables (Mem)*
|                                                                 | 
+------------------------------------------------+0x0000

> 
> Can you move the metadata changes to a separate patch please?
> 
Yes, the metadata changes will be in a separate patch in the next version.

Thanks!
Min