Re: [PATCH v2 11/11] OvmfPkg/AmdSev: Enforce hash verification of kernel blobs

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

On 7/6/21 3:55 AM, Dov Murik wrote:
> In the AmdSevX86 build, use SevHashesBlobVerifierLib to enforce
> verification of hashes of the kernel/initrd/cmdline blobs fetched from
> firmware config.
> 
> This allows for secure (measured) boot of SEV guests with QEMU's
> -kernel/-initrd/-append switches (with the corresponding QEMU support
> for injecting the hashes table into initial measured guest memory).
> 
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Ashish Kalra <ashish.kalra@amd.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3457
> Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  OvmfPkg/AmdSev/AmdSevX64.dsc | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
> index 8b260df114e3..d1ed0abbd0fb 100644
> --- a/OvmfPkg/AmdSev/AmdSevX64.dsc
> +++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
> @@ -173,7 +173,7 @@ [LibraryClasses]
>    LockBoxLib|OvmfPkg/Library/LockBoxLib/LockBoxBaseLib.inf
>    CustomizedDisplayLib|MdeModulePkg/Library/CustomizedDisplayLib/CustomizedDisplayLib.inf
>    FrameBufferBltLib|MdeModulePkg/Library/FrameBufferBltLib/FrameBufferBltLib.inf
> -  BlobVerifierLib|OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf
> +  BlobVerifierLib|OvmfPkg/Library/BlobVerifierLib/SevHashesBlobVerifierLib.inf
>  
>  !if $(SOURCE_DEBUG_ENABLE) == TRUE
>    PeCoffExtraActionLib|SourceLevelDebugPkg/Library/PeCoffExtraActionLibDebug/PeCoffExtraActionLibDebug.inf
> @@ -696,7 +696,7 @@ [Components]
>    }
>    OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.inf {
>      <LibraryClasses>
> -      NULL|OvmfPkg/Library/BlobVerifierLib/NullBlobVerifierLib.inf
> +      NULL|OvmfPkg/Library/BlobVerifierLib/SevHashesBlobVerifierLib.inf
>    }
>    OvmfPkg/VirtioPciDeviceDxe/VirtioPciDeviceDxe.inf
>    OvmfPkg/Virtio10Dxe/Virtio10.inf
>