Re: [edk2-devel] [PATCH v1 0/4] Support SMM Relocated SmBase handling

["Gerd Hoffmann" <kraxel@redhat.com>]

On Fri, Jan 13, 2023 at 10:18:59AM +0000, Wu, Jiaxin wrote:
> Thanks Comments Gerd, I will resolve the CI check issue (I have noticed that in https://github.com/tianocore/edk2/pull/3884) & refine the usage description in next version.
> 
> Anyway, Ray also helped explain the usage as below, I will integrate it in the hob definition .h file, help below can help understand the design.:
> 
> The default SMBASE for the x86 processor is 0x30000. When SMI happens, CPU runs the
> SMI handler at SMBASE+0x8000. Also, the SMM save state area is within SMBASE+0x10000.
> 
> One of the SMM initialization from CPU perspective is to program the new SMBASE (in TSEG range)
> for each CPU thread. When the SMBASE update happens in a PEI module, the PEI module shall
> produce the SMM_BASE_HOB in HOB database which tells the PiSmmCpuDxeSmm driver which runs
> at a later phase about the new SMBASE for each CPU thread.

There are no PEI module changes in this patch series.

So where does the HOB come from?

And what are the reasons for setting SMBASE in a PEI module instead
of PiSmmCpuDxeSmm?

take care,
  Gerd