Re: [PATCH v2 0/2] OvmfPkg: Enable measured direct boot on AMD SEV-SNP

["Dov Murik" <dovmurik@linux.ibm.com>]

On 16/02/2023 10:06, Dov Murik wrote:
> (Note: This is a new version of this one-year-old patch series; the v1
> series [1] got a few Acked-by but it's been so long that I don't
> consider them relevant anymore.)
> 
> AMD SEV and SEV-ES support measured direct boot with
> kernel/initrd/cmdline hashes injected by QEMU and verified by OVMF
> during boot.
> 
> To enable the same approach for AMD SEV-SNP we make sure the page in
> which QEMU inserts the hashes of kernel/initrd/cmdline is not already
> pre-validated, as SNP doesn't allow validating a page twice.
> 
> The first patch rearranges the pages in AmdSevX64's MEMFD so they are in
> the same order both as in the main target (OvmfPkgX64), with the
> exception of the SEV Launch Secret page which isn't defined in
> OvmfPkgX64.
> 
> The second patch modifies the SNP metadata structure such that on
> AmdSev target the SEV Launch Secret page is not included in the ranges
> that are pre-validated (zero pages) by the VMM; instead the VMM will
> insert content into this page (the hashes table), or mark it explicitly
> as a zero page if no hashes are added.
> 
> A corresponding RFC patch to QEMU will be published soon in qemu-devel.

The corresponding QEMU RFC patch series is at:

  https://lore.kernel.org/qemu-devel/20230216084913.2148508-1-dovmurik@linux.ibm.com/

and the QEMU tree can be fetched from:

  https://github.com/confidential-containers-demo/qemu/tree/snp-kernel-hashes-v2

This edk2 series is also published at:

  https://github.com/confidential-containers-demo/edk2/tree/snp-kernel-hashes-v2



-Dov


> 
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Michael Roth <michael.roth@amd.com>
> Cc: Ashish Kalra <ashish.kalra@amd.com>
> Cc: Mario Smarduch <mario.smarduch@amd.com>
> Cc: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>
> 
> ---
> 
> v2 changes:
> * Rebased on master
> * Updated AmdSev MEMFD size to match OvmfX64
> 
> v1:
> [1] https://edk2.groups.io/g/devel/message/88137
> 
> 
> Dov Murik (2):
>   OvmfPkg/AmdSev: Reorder MEMFD pages to match the order in
>     OvmfPkgX64.fdf
>   OvmfPkg/ResetVector: Exclude SEV launch secrets page from
>     pre-validation
> 
>  OvmfPkg/AmdSev/AmdSevX64.fdf          | 27 ++++++++++----------
>  OvmfPkg/ResetVector/ResetVector.nasmb | 14 +++++++++-
>  2 files changed, 27 insertions(+), 14 deletions(-)
>