OvmfPkg: reserve SNP secrets page

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

During the SNP guest launch sequence, a special secrets page needs to be
inserted by the VMM. The PSP will populate the page; it will contain the
VM Platform Communication Key (VMPCKs) used by the guest to send and
receive secure messages to the PSP.

The purpose of the secrets page in the SEV-SNP is different from the one
used in SEV guests. In SEV, the secrets page contains the guest owner's
private data after the remote attestation.

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>
This commit is contained in:
Brijesh Singh via groups.io 2021-12-09 11:27:33 +08:00 committed by mergify[bot]
parent 3053183d41
commit 707c71a01b
5 changed files with 23 additions and 0 deletions

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@ -350,6 +350,13 @@
gUefiOvmfPkgTokenSpaceGuid.PcdBfvRawDataOffset|0|UINT32|0x56
gUefiOvmfPkgTokenSpaceGuid.PcdBfvRawDataSize|0|UINT32|0x57
## The base address and size of the SEV-SNP Secrets Area that contains
# the VM platform communication key used to send and recieve the
# messages to the PSP. If this is set in the .fdf, the platform
# is responsible to reserve this area from DXE phase overwrites.
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase|0|UINT32|0x58
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize|0|UINT32|0x59
[PcdsDynamic, PcdsDynamicEx]
gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent|0|UINT64|2
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable|FALSE|BOOLEAN|0x10

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@ -88,6 +88,9 @@ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvm
0x00C000|0x001000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize
0x00D000|0x001000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
0x010000|0x010000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize

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@ -59,3 +59,5 @@
gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableBase
gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize

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@ -103,6 +103,8 @@
%define SEV_ES_WORK_AREA_RDRAND (FixedPcdGet32 (PcdSevEsWorkAreaBase) + 8)
%define SEV_ES_WORK_AREA_ENC_MASK (FixedPcdGet32 (PcdSevEsWorkAreaBase) + 16)
%define SEV_ES_VC_TOP_OF_STACK (FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) + FixedPcdGet32 (PcdOvmfSecPeiTempRamSize))
%define SEV_SNP_SECRETS_BASE (FixedPcdGet32 (PcdOvmfSnpSecretsBase))
%define SEV_SNP_SECRETS_SIZE (FixedPcdGet32 (PcdOvmfSnpSecretsSize))
%include "X64/IntelTdxMetadata.asm"
%include "Ia32/Flat32ToFlat64.asm"

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@ -14,6 +14,9 @@ BITS 64
; 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
ALIGN 16
TIMES (15 - ((OvmfSevGuidedStructureEnd - OvmfSevGuidedStructureStart + 15) % 16)) DB 0
@ -30,5 +33,11 @@ _DescriptorSev:
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
OvmfSevGuidedStructureEnd:
ALIGN 16