From: Tom Lendacky <thomas.lenda...@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3345
The TPM support in OVMF performs MMIO accesses during the PEI phase. At
this point, MMIO ranges have not been marked un-encyrpted, so an SEV-ES
guest will fail attempting to perform MMIO to an encrypted address.
Read the PcdTpmBaseAddress and mark the specification defined range
(0x5000 in length) as un-encrypted, to allow an SEV-ES guest to process
the MMIO requests.
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Brijesh Singh <brijesh.si...@amd.com>
Cc: James Bottomley <j...@linux.ibm.com>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Min Xu <min.m...@intel.com>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/PlatformPei/PlatformPei.inf | 1 +
OvmfPkg/PlatformPei/AmdSev.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf
b/OvmfPkg/PlatformPei/PlatformPei.inf
index 6ef77ba7bb21..de60332e9390 100644
--- a/OvmfPkg/PlatformPei/PlatformPei.inf
+++ b/OvmfPkg/PlatformPei/PlatformPei.inf
@@ -113,6 +113,7 @@ [Pcd]
[FixedPcd]
gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress
+ gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress
gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiACPIMemoryNVS
gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiACPIReclaimMemory
gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiReservedMemoryType
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index dddffdebda4b..d524929f9e10 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -141,6 +141,7 @@ AmdSevInitialize (
)
{
UINT64 EncryptionMask;
+ UINT64 TpmBaseAddress;
RETURN_STATUS PcdStatus;
//
@@ -206,6 +207,24 @@ AmdSevInitialize (
}
}
+ //
+ // PEI TPM support will perform MMIO accesses, be sure this range is not
+ // marked encrypted.
+ //
+ TpmBaseAddress = PcdGet64 (PcdTpmBaseAddress);
+ if (TpmBaseAddress != 0) {
+ RETURN_STATUS DecryptStatus;
+
+ DecryptStatus = MemEncryptSevClearPageEncMask (
+ 0,
+ TpmBaseAddress,
+ EFI_SIZE_TO_PAGES (0x5000),
+ FALSE
+ );
+
+ ASSERT_RETURN_ERROR (DecryptStatus);
+ }
+
//
// Check and perform SEV-ES initialization if required.
//
--
2.31.0
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