Re: [RFC v5 0/8] Stack trace support in X64 exception handling

[Paulo Alcantara <paulo@paulo.ac>]

"Yao, Jiewen" <jiewen.yao@intel.com> writes:

Hi Jiewen,

> =======================
> OVMF IA32: DXE worked, but SMM not.
>
> Since the page fault is only occurring in IA32 with no paging enabled 
> (default case), I suspect that when we don't have paging, we are unable 
> to successfully validate the memory address when it's i.e. outside SMRAM 
> - that is, we don't know when to stop unwinding the stack.
> =======================
>
> For IA32 SMM, I am a little confused.
> We unconditionally setup page table for SMM, no matter it is IA32 or X64.
>
> If you find a SMM driver running in a page-disable environment, it means, the SMM CORE load the driver in SMRAM, but the SMM CPU driver has not rebased the CPU yet.
> SMM driver is still using the PageTable/GDT/IDT setup by DXE CPU
> driver, not SMM CPU driver.

OK - thanks for clarifying that.

> Would you please double confirm what you have observed?
>
> You can just check the boot log file to see if PiSmmCpu driver has run
> or not.

Sure. I will do it and then get back to you once I got the results.

Thanks
Paulo