diff options
3 files changed, 78 insertions, 0 deletions
diff --git a/OvmfPkg/Include/Library/MemEncryptSevLib.h b/OvmfPkg/Include/Library/MemEncryptSevLib.h index e5ebb44018..1e2ec8641d 100644 --- a/OvmfPkg/Include/Library/MemEncryptSevLib.h +++ b/OvmfPkg/Include/Library/MemEncryptSevLib.h @@ -86,4 +86,27 @@ MemEncryptSevSetPageEncMask ( IN UINTN NumPages,
IN BOOLEAN Flush
);
+
+
+/**
+ Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM
+ Save State Map.
+
+ @param[out] BaseAddress The base address of the lowest-address page that
+ covers the initial SMRAM Save State Map.
+
+ @param[out] NumberOfPages The number of pages in the page range that covers
+ the initial SMRAM Save State Map.
+
+ @retval RETURN_SUCCESS BaseAddress and NumberOfPages have been set on
+ output.
+
+ @retval RETURN_UNSUPPORTED SMM is unavailable.
+**/
+RETURN_STATUS
+EFIAPI
+MemEncryptSevLocateInitialSmramSaveStateMapPages (
+ OUT UINTN *BaseAddress,
+ OUT UINTN *NumberOfPages
+ );
#endif // _MEM_ENCRYPT_SEV_LIB_H_
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/BaseMemEncryptSevLib.inf b/OvmfPkg/Library/BaseMemEncryptSevLib/BaseMemEncryptSevLib.inf index 2f0a2392a7..464fe1f33e 100644 --- a/OvmfPkg/Library/BaseMemEncryptSevLib/BaseMemEncryptSevLib.inf +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/BaseMemEncryptSevLib.inf @@ -51,3 +51,7 @@ CpuLib
DebugLib
MemoryAllocationLib
+ PcdLib
+
+[FeaturePcd]
+ gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c b/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c index 7078ab0d3f..b92ba50c61 100644 --- a/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c @@ -17,9 +17,13 @@ #include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/MemEncryptSevLib.h>
+#include <Library/PcdLib.h>
#include <Register/Amd/Cpuid.h>
#include <Register/Amd/Msr.h>
#include <Register/Cpuid.h>
+#include <Register/QemuSmramSaveStateMap.h>
+#include <Register/SmramSaveStateMap.h>
+#include <Uefi/UefiBaseType.h>
STATIC BOOLEAN mSevStatus = FALSE;
STATIC BOOLEAN mSevStatusChecked = FALSE;
@@ -87,3 +91,50 @@ MemEncryptSevIsEnabled ( return mSevStatus;
}
+
+
+/**
+ Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM
+ Save State Map.
+
+ @param[out] BaseAddress The base address of the lowest-address page that
+ covers the initial SMRAM Save State Map.
+
+ @param[out] NumberOfPages The number of pages in the page range that covers
+ the initial SMRAM Save State Map.
+
+ @retval RETURN_SUCCESS BaseAddress and NumberOfPages have been set on
+ output.
+
+ @retval RETURN_UNSUPPORTED SMM is unavailable.
+**/
+RETURN_STATUS
+EFIAPI
+MemEncryptSevLocateInitialSmramSaveStateMapPages (
+ OUT UINTN *BaseAddress,
+ OUT UINTN *NumberOfPages
+ )
+{
+ UINTN MapStart;
+ UINTN MapEnd;
+ UINTN MapPagesStart; // MapStart rounded down to page boundary
+ UINTN MapPagesEnd; // MapEnd rounded up to page boundary
+ UINTN MapPagesSize; // difference between MapPagesStart and MapPagesEnd
+
+ if (!FeaturePcdGet (PcdSmmSmramRequire)) {
+ return RETURN_UNSUPPORTED;
+ }
+
+ MapStart = SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET;
+ MapEnd = MapStart + sizeof (QEMU_SMRAM_SAVE_STATE_MAP);
+ MapPagesStart = MapStart & ~(UINTN)EFI_PAGE_MASK;
+ MapPagesEnd = ALIGN_VALUE (MapEnd, EFI_PAGE_SIZE);
+ MapPagesSize = MapPagesEnd - MapPagesStart;
+
+ ASSERT ((MapPagesSize & EFI_PAGE_MASK) == 0);
+
+ *BaseAddress = MapPagesStart;
+ *NumberOfPages = MapPagesSize >> EFI_PAGE_SHIFT;
+
+ return RETURN_SUCCESS;
+}
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