Re: [RFC PATCH 02/14] OvmfPkg/PlatformPei: Mark SEC GHCB page in the page encrpytion bitmap.

["Ashish Kalra" <ashish.kalra@amd.com>]

Hello Tobin,

Just a high level question, why is this patch included in this
patch series, i don't think you are supporting SEV-ES platform 
migration in this patch-set ?

Thanks,
Ashish

On Tue, Mar 02, 2021 at 03:48:27PM -0500, Tobin Feldman-Fitzthum wrote:
> From: Ashish Kalra <ashish.kalra@amd.com>
> 
> Mark the SEC GHCB page that is mapped as unencrypted in
> ResetVector code in the hypervisor page encryption bitmap.
> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
> 
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> ---
>  OvmfPkg/PlatformPei/AmdSev.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
> index dddffdebda..c72eeb37c5 100644
> --- a/OvmfPkg/PlatformPei/AmdSev.c
> +++ b/OvmfPkg/PlatformPei/AmdSev.c
> @@ -15,6 +15,7 @@
>  #include <Library/HobLib.h>
>  #include <Library/MemEncryptSevLib.h>
>  #include <Library/MemoryAllocationLib.h>
> +#include <Library/MemEncryptHypercallLib.h>
>  #include <Library/PcdLib.h>
>  #include <PiPei.h>
>  #include <Register/Amd/Msr.h>
> @@ -52,6 +53,15 @@ AmdSevEsInitialize (
>    PcdStatus = PcdSetBoolS (PcdSevEsIsEnabled, TRUE);
>    ASSERT_RETURN_ERROR (PcdStatus);
>  
> +  //
> +  // GHCB_BASE setup during reset-vector needs to be marked as
> +  // decrypted in the hypervisor page encryption bitmap.
> +  //
> +  SetMemoryEncDecHypercall3 (FixedPcdGet32 (PcdOvmfSecGhcbBase),
> +    EFI_SIZE_TO_PAGES(FixedPcdGet32 (PcdOvmfSecGhcbSize)),
> +    FALSE
> +    );
> +
>    //
>    // Allocate GHCB and per-CPU variable pages.
>    //   Since the pages must survive across the UEFI to OS transition
> -- 
> 2.20.1
>