BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
The VMM launch sequence should have pre-validated all the data pages used
in the Reset vector. The range does not cover the data pages used during
the SEC phase (mainly PEI and DXE firmware volume decompression memory).
When SEV-SNP is active, the memory must be pre-validated before the access.
Add support to pre-validate the memory range from SnpSecPreValidatedStart
to SnpSecPreValidatedEnd. This should be sufficent to enter into the PEI
phase.
Cc: James Bottomley <j...@linux.ibm.com>
Cc: Min Xu <min.m...@intel.com>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org>
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Erdem Aktas <erdemak...@google.com>
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
---
OvmfPkg/FvmainCompactScratchEnd.fdf.inc | 5 ++++
OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf | 2 ++
OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c | 5 ++++
OvmfPkg/OvmfPkg.dec | 5 ++++
OvmfPkg/Sec/SecMain.c | 27
++++++++++++++++++++
OvmfPkg/Sec/SecMain.inf | 3 +++
6 files changed, 47 insertions(+)
diff --git a/OvmfPkg/FvmainCompactScratchEnd.fdf.inc
b/OvmfPkg/FvmainCompactScratchEnd.fdf.inc
index 46f5258329..b560fb0b8e 100644
--- a/OvmfPkg/FvmainCompactScratchEnd.fdf.inc
+++ b/OvmfPkg/FvmainCompactScratchEnd.fdf.inc
@@ -63,3 +63,8 @@ DEFINE DECOMP_SCRATCH_BASE_MASK = 0xFFF00000
DEFINE DECOMP_SCRATCH_BASE = (($(DECOMP_SCRATCH_BASE_UNALIGNED) +
$(DECOMP_SCRATCH_BASE_ALIGNMENT)) & $(DECOMP_SCRATCH_BASE_MASK))
SET gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDecompressionScratchEnd =
$(DECOMP_SCRATCH_BASE) + $(DECOMP_SCRATCH_SIZE)
+
+#
+# The range of pages that should be pre-validated during the SEC phase when
SEV-SNP is active in the guest VM.
+SET gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedStart =
$(MEMFD_BASE_ADDRESS) + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfPeiMemFvBase
+SET gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedEnd =
$(DECOMP_SCRATCH_BASE) + $(DECOMP_SCRATCH_SIZE)
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
b/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
index f4058911e7..2b60920f4b 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
@@ -58,5 +58,7 @@
[FixedPcd]
gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedEnd
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedStart
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedEnd
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedStart
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c
b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c
index ff4c0742ed..7d8e681acd 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c
@@ -27,6 +27,11 @@ STATIC SNP_PRE_VALIDATED_RANGE mPreValidatedRange[] = {
{
FixedPcdGet32 (PcdOvmfSnpHypervisorPreValidatedStart),
FixedPcdGet32 (PcdOvmfSnpHypervisorPreValidatedEnd)
+ },
+ // This range is pre-validated by the Sec/SecMain.c
+ {
+ FixedPcdGet32 (PcdOvmfSnpSecPreValidatedStart),
+ FixedPcdGet32 (PcdOvmfSnpSecPreValidatedEnd)
}
};
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 70948ab478..d1bfe49731 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -332,6 +332,11 @@
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedStart|0x0|UINT32|0x49
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpHypervisorPreValidatedEnd|0x0|UINT32|0x50
+ ## The range of memory that need to be pre-validated in the SEC phase
+ # when SEV-SNP is active in the guest VM.
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedStart|0|UINT32|0x51
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedEnd|0|UINT32|0x52
+
[PcdsDynamic, PcdsDynamicEx]
gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent|0|UINT64|2
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable|FALSE|BOOLEAN|0x10
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index 7c9650ba8f..c5467465ab 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -907,6 +907,26 @@ SevEsIsEnabled (
return ((SevEsWorkArea != NULL) && (SevEsWorkArea->SevEsEnabled != 0));
}
+/**
+ Pre-validate System RAM used for decompressing the PEI and DXE firmware
volumes
+ when SEV-SNP is active. The PCDs SecPreValidatedStart and SecPreValidatedEnd
are
+ set in OvmfPkg/FvmainCompactScratchEnd.fdf.inc.
+
+**/
+STATIC
+VOID
+SevSnpSecPreValidateSystemRam (
+ VOID
+ )
+{
+ PHYSICAL_ADDRESS Start, End;
+
+ Start = (EFI_PHYSICAL_ADDRESS)(UINTN) PcdGet32
(PcdOvmfSnpSecPreValidatedStart);
+ End = (EFI_PHYSICAL_ADDRESS)(UINTN) PcdGet32 (PcdOvmfSnpSecPreValidatedEnd);
+
+ MemEncryptSevSnpPreValidateSystemRam (Start, EFI_SIZE_TO_PAGES (End -
Start));
+}
+
VOID
EFIAPI
SecCoreStartupWithStack (
@@ -1038,6 +1058,13 @@ SecCoreStartupWithStack (
SecCoreData.BootFirmwareVolumeBase = BootFv;
SecCoreData.BootFirmwareVolumeSize = (UINTN) BootFv->FvLength;
+ if (SevSnpIsEnabled ()) {
+ //
+ // Pre-validate the System RAM used in the SEC Phase
+ //
+ SevSnpSecPreValidateSystemRam ();
+ }
+
//
// Make sure the 8259 is masked before initializing the Debug Agent and the
debug timer is enabled
//
diff --git a/OvmfPkg/Sec/SecMain.inf b/OvmfPkg/Sec/SecMain.inf
index 7f78dcee27..8144b1d115 100644
--- a/OvmfPkg/Sec/SecMain.inf
+++ b/OvmfPkg/Sec/SecMain.inf
@@ -50,6 +50,7 @@
PeCoffExtraActionLib
ExtractGuidedSectionLib
LocalApicLib
+ MemEncryptSevLib
CpuExceptionHandlerLib
[Ppis]
@@ -70,6 +71,8 @@
gUefiOvmfPkgTokenSpaceGuid.PcdGuidedExtractHandlerTableSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDecompressionScratchEnd
gEfiMdeModulePkgTokenSpaceGuid.PcdInitValueInTempStack
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedStart
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecPreValidatedEnd
[FeaturePcd]
gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
--
2.17.1
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#74651): https://edk2.groups.io/g/devel/message/74651
Mute This Topic: https://groups.io/mt/82479077/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
