Re: [PATCH V5 2/2] OvmfPkg/ResetVector: Enable Intel TDX in ResetVector of Ovmf

["Erdem Aktas" <erdemaktas@google.com>]

On Mon, Aug 30, 2021 at 5:35 AM Min Xu <min.m.xu@intel.com> wrote:
> +;
> +; Check if it is Intel Tdx
> +;
> +; Modified: EAX, EBX, ECX, EDX
> +;
> +; If it is Intel Tdx, EAX is zero
> +; If it is not Intel Tdx, EAX is non-zero
> +;
> +IsTdx:

IsTdx returns 0 when TDX is enabled in CPUID but IsTdxEnabled return 1
when TDX is enabled. Is this intentional?

here is how IsTdxEnabled defined.
; If TDX is enabled then EAX will be 1
; If TDX is disabled then EAX will be 0.
;
IsTdxEnabled:

> +    ;
> +    ; In Td guest, BSP/AP shares the same entry point
> +    ; BSP builds up the page table, while APs shouldn't do the same task.
> +    ; Instead, APs just leverage the page table which is built by BSP.
> +    ; APs will wait until the page table is ready.
> +    ;
> +TdxApWait:
> +    cmp     byte[TDX_WORK_AREA_PGTBL_READY], 0
> +    je      TdxApWait
> +    jmp     ExitInitTdxWorkarea

Don't we need memory fence before  je      TdxApWait


> +; Check TDX features, Non-TDX or TDX-BSP or TDX-APs?
> +;
> +; By design TDX BSP is reponsible for inintializing the PageTables.
s/reponsible/responsible
s/inintializing/initializing