cca9cd3dd6
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275 Platform features and capabilities are traditionally discovered via the CPUID instruction. Hypervisors typically trap and emulate the CPUID instruction for a variety of reasons. There are some cases where incorrect CPUID information can potentially lead to a security issue. The SEV-SNP firmware provides a feature to filter the CPUID results through the PSP. The filtered CPUID values are saved on a special page for the guest to consume. Reserve a page in MEMFD that will contain the results of filtered CPUID values. Cc: Michael Roth <michael.roth@amd.com> Cc: James Bottomley <jejb@linux.ibm.com> Cc: Min Xu <min.m.xu@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org> Cc: Erdem Aktas <erdemaktas@google.com> Cc: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Jiewen Yao <Jiewen.yao@intel.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
60 lines
1.7 KiB
NASM
60 lines
1.7 KiB
NASM
;-----------------------------------------------------------------------------
|
|
; @file
|
|
; OVMF metadata for the AMD SEV confidential computing guests
|
|
;
|
|
; Copyright (c) 2021, AMD Inc. All rights reserved.<BR>
|
|
;
|
|
; SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
;-----------------------------------------------------------------------------
|
|
|
|
BITS 64
|
|
|
|
%define OVMF_SEV_METADATA_VERSION 1
|
|
|
|
; The section must be accepted or validated by the VMM before the boot
|
|
%define OVMF_SECTION_TYPE_SNP_SEC_MEM 0x1
|
|
|
|
; AMD SEV-SNP specific sections
|
|
%define OVMF_SECTION_TYPE_SNP_SECRETS 0x2
|
|
|
|
;
|
|
; The section contains the hypervisor pre-populated CPUID values.
|
|
; In the case of SEV-SNP, the CPUID values are filtered and measured by
|
|
; the SEV-SNP firmware.
|
|
; The CPUID format is documented in SEV-SNP firmware spec 0.9 section 7.1
|
|
; (CPUID function structure).
|
|
;
|
|
%define OVMF_SECTION_TYPE_CPUID 0x3
|
|
|
|
|
|
ALIGN 16
|
|
|
|
TIMES (15 - ((OvmfSevGuidedStructureEnd - OvmfSevGuidedStructureStart + 15) % 16)) DB 0
|
|
|
|
OvmfSevGuidedStructureStart:
|
|
;
|
|
; OvmfSev metadata descriptor
|
|
;
|
|
OvmfSevMetadataGuid:
|
|
|
|
_DescriptorSev:
|
|
DB 'A','S','E','V' ; Signature
|
|
DD OvmfSevGuidedStructureEnd - _DescriptorSev ; Length
|
|
DD OVMF_SEV_METADATA_VERSION ; Version
|
|
DD (OvmfSevGuidedStructureEnd - _DescriptorSev - 16) / 12 ; Number of sections
|
|
|
|
; SEV-SNP Secrets page
|
|
SevSnpSecrets:
|
|
DD SEV_SNP_SECRETS_BASE
|
|
DD SEV_SNP_SECRETS_SIZE
|
|
DD OVMF_SECTION_TYPE_SNP_SECRETS
|
|
|
|
; CPUID values
|
|
CpuidSec:
|
|
DD CPUID_BASE
|
|
DD CPUID_SIZE
|
|
DD OVMF_SECTION_TYPE_CPUID
|
|
|
|
OvmfSevGuidedStructureEnd:
|
|
ALIGN 16
|