REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3394
Add new API GetMaxPlatformAddressBits to get the max platform address
bits. Max physical address bits can be get from CPUID. When TME-MK
feature is enabled, the upper bits of the max physical address bits
are repurposed for usage as a KeyID.
Therefore, the max platform addressable bits is the max physical
address bits minus the upper bits used for KeyID if TME-MK is enable.
Cc: Michael D Kinney <michael.d.kin...@intel.com>
Cc: Liming Gao <gaolim...@byosoft.com.cn>
Signed-off-by: Zhiguang Liu <zhiguang....@intel.com>
---
MdePkg/Include/Library/CpuLib.h | 25 +++++++
MdePkg/Library/BaseCpuLib/X86BaseCpuLib.c | 81 +++++++++++++++++++++++
2 files changed, 106 insertions(+)
diff --git a/MdePkg/Include/Library/CpuLib.h b/MdePkg/Include/Library/CpuLib.h
index 3f29937dc7..a9bac083b7 100644
--- a/MdePkg/Include/Library/CpuLib.h
+++ b/MdePkg/Include/Library/CpuLib.h
@@ -87,6 +87,31 @@ GetCpuSteppingId (
VOID
);
+/**
+ Get the max platform addressable bits.
+ Max physical address bits can be get from CPUID. When TME-MK feature
+ is enabled, the upper bits of the max physical address bits are
+ repurposed for usage as a KeyID.
+ Therefore, the max platform addressable bits is the max physical
+ address bits minus the upper bits used for KeyID if TME-MK is enable.
+
+ @param[out] ValidAddressMask Bitmask with valid address bits set to
+ one; other bits are clear. Optional
+ parameter.
+
+ @param[out] ValidPageBaseAddressMask Bitmask with valid page base address
+ bits set to one; other bits are clear.
+ Optional parameter.
+
+ @return The max platform addressable bits.
+**/
+UINT8
+EFIAPI
+GetMaxPlatformAddressBits (
+ OUT UINT64 *ValidAddressMask OPTIONAL,
+ OUT UINT64 *ValidPageBaseAddressMask OPTIONAL
+ );
+
#endif
#endif
diff --git a/MdePkg/Library/BaseCpuLib/X86BaseCpuLib.c
b/MdePkg/Library/BaseCpuLib/X86BaseCpuLib.c
index 1cad32a4be..7b15cb3d73 100644
--- a/MdePkg/Library/BaseCpuLib/X86BaseCpuLib.c
+++ b/MdePkg/Library/BaseCpuLib/X86BaseCpuLib.c
@@ -14,6 +14,8 @@
#include <Library/BaseLib.h>
#include <Library/CpuLib.h>
+#include <Register/Intel/ArchitecturalMsr.h>
+#include <Uefi/UefiBaseType.h>
/**
Determine if the standard CPU signature is "AuthenticAMD".
@@ -79,3 +81,82 @@ GetCpuSteppingId (
return (UINT8)Eax.Bits.SteppingId;
}
+
+/**
+ Get the max platform addressable bits.
+ Max physical address bits can be get from CPUID. When TME-MK feature
+ is enabled, the upper bits of the max physical address bits are
+ repurposed for usage as a KeyID.
+ Therefore, the max platform addressable bits is the max physical
+ address bits minus the upper bits used for KeyID if TME-MK is enable.
+
+ @param[out] ValidAddressMask Bitmask with valid address bits set to
+ one; other bits are clear. Optional
+ parameter.
+
+ @param[out] ValidPageBaseAddressMask Bitmask with valid page base address
+ bits set to one; other bits are clear.
+ Optional parameter.
+
+ @return The max platform addressable bits.
+**/
+UINT8
+EFIAPI
+GetMaxPlatformAddressBits (
+ OUT UINT64 *ValidAddressMask OPTIONAL,
+ OUT UINT64 *ValidPageBaseAddressMask OPTIONAL
+ )
+{
+ UINT32 MaxExtendedFunction;
+ CPUID_VIR_PHY_ADDRESS_SIZE_EAX VirPhyAddressSize;
+ UINT64 AddressMask;
+ UINT64 PageBaseAddressMask;
+ UINT32 MaxFunction;
+ CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_ECX ExtendedFeatureFlagsEcx;
+ MSR_IA32_TME_ACTIVATE_REGISTER TmeActivate;
+ MSR_IA32_TME_CAPABILITY_REGISTER TmeCapability;
+
+ AsmCpuid (CPUID_EXTENDED_FUNCTION, &MaxExtendedFunction, NULL, NULL, NULL);
+ if (MaxExtendedFunction >= CPUID_VIR_PHY_ADDRESS_SIZE) {
+ AsmCpuid (
+ CPUID_VIR_PHY_ADDRESS_SIZE,
+ &VirPhyAddressSize.Uint32,
+ NULL,
+ NULL,
+ NULL
+ );
+ } else {
+ VirPhyAddressSize.Bits.PhysicalAddressBits = 36;
+ }
+
+ //
+ // CPUID enumeration of MAX_PA is unaffected by TME-MK activation and will
continue
+ // to report the maximum physical address bits available for software to use,
+ // irrespective of the number of KeyID bits.
+ // So, we need to check if TME is enabled and adjust the PA size accordingly.
+ //
+ AsmCpuid (CPUID_SIGNATURE, &MaxFunction, NULL, NULL, NULL);
+ if (MaxFunction >= CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS) {
+ AsmCpuidEx (CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, 0, NULL, NULL,
&ExtendedFeatureFlagsEcx.Uint32, NULL);
+ if (ExtendedFeatureFlagsEcx.Bits.TME_EN == 1) {
+ TmeActivate.Uint64 = AsmReadMsr64 (MSR_IA32_TME_ACTIVATE);
+ TmeCapability.Uint64 = AsmReadMsr64 (MSR_IA32_TME_CAPABILITY);
+ if ((TmeActivate.Bits.TmeEnable == 1) &&
(TmeCapability.Bits.MkTmeMaxKeyidBits != 0)) {
+ VirPhyAddressSize.Bits.PhysicalAddressBits -=
TmeActivate.Bits.MkTmeKeyidBits;
+ }
+ }
+ }
+
+ AddressMask = LShiftU64 (1,
VirPhyAddressSize.Bits.PhysicalAddressBits) - 1;
+ PageBaseAddressMask = AddressMask & ~(UINT64)EFI_PAGE_MASK;
+
+ if (ValidAddressMask != NULL) {
+ *ValidAddressMask = AddressMask;
+ }
+
+ if (ValidPageBaseAddressMask != NULL) {
+ *ValidPageBaseAddressMask = PageBaseAddressMask;
+ }
+
+ return (UINT8)VirPhyAddressSize.Bits.PhysicalAddressBits;
+}
--
2.31.1.windows.1
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