UefiCpuPkg: Support TDX in BaseXApicX2ApicLib

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

MSR is accessed in BaseXApicX2ApicLib. In TDX some MSRs are accessed
directly from/to CPU. Some should be accessed via explicit requests
from the host VMM using TDCALL(TDG.VP.VMCALL). This is done by the
help of TdxLib.

Please refer to [TDX] Section 18.1
TDX: https://software.intel.com/content/dam/develop/external/us/en/
documents/tdx-module-1.0-public-spec-v0.931.pdf

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c

@@ -23,11 +23,155 @@
 #include <Library/TimerLib.h>
 #include <Library/PcdLib.h>
 #include <Library/UefiCpuLib.h>
+#include <IndustryStandard/Tdx.h>
 
 //
 // Library internal functions
 //
 
+/**
+  Some MSRs in TDX are accessed via TdCall.
+  Some are directly read/write from/to CPU.
+
+  @param  MsrIndex  Index of the MSR
+  @retval TRUE      MSR accessed via TdCall.
+  @retval FALSE     MSR accessed not via TdCall.
+
+**/
+BOOLEAN
+AccessMsrTdxCall (
+  IN UINT32  MsrIndex
+  )
+{
+  if (!TdIsEnabled ()) {
+    return FALSE;
+  }
+
+  switch (MsrIndex) {
+    case MSR_IA32_X2APIC_TPR:
+    case MSR_IA32_X2APIC_PPR:
+    case MSR_IA32_X2APIC_EOI:
+    case MSR_IA32_X2APIC_ISR0:
+    case MSR_IA32_X2APIC_ISR1:
+    case MSR_IA32_X2APIC_ISR2:
+    case MSR_IA32_X2APIC_ISR3:
+    case MSR_IA32_X2APIC_ISR4:
+    case MSR_IA32_X2APIC_ISR5:
+    case MSR_IA32_X2APIC_ISR6:
+    case MSR_IA32_X2APIC_ISR7:
+    case MSR_IA32_X2APIC_TMR0:
+    case MSR_IA32_X2APIC_TMR1:
+    case MSR_IA32_X2APIC_TMR2:
+    case MSR_IA32_X2APIC_TMR3:
+    case MSR_IA32_X2APIC_TMR4:
+    case MSR_IA32_X2APIC_TMR5:
+    case MSR_IA32_X2APIC_TMR6:
+    case MSR_IA32_X2APIC_TMR7:
+    case MSR_IA32_X2APIC_IRR0:
+    case MSR_IA32_X2APIC_IRR1:
+    case MSR_IA32_X2APIC_IRR2:
+    case MSR_IA32_X2APIC_IRR3:
+    case MSR_IA32_X2APIC_IRR4:
+    case MSR_IA32_X2APIC_IRR5:
+    case MSR_IA32_X2APIC_IRR6:
+    case MSR_IA32_X2APIC_IRR7:
+      return FALSE;
+    default:
+      break;
+  }
+
+  return TRUE;
+}
+
+/**
+  Read MSR value.
+
+  @param  MsrIndex  Index of the MSR to read
+  @retval 64-bit    Value of MSR.
+
+**/
+UINT64
+LocalApicReadMsrReg64 (
+  IN UINT32  MsrIndex
+  )
+{
+  UINT64  Val;
+  UINT64  Status;
+
+  if (AccessMsrTdxCall (MsrIndex)) {
+    Status = TdVmCall (TDVMCALL_RDMSR, (UINT64)MsrIndex, 0, 0, 0, &Val);
+    if (Status != 0) {
+      TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+    }
+  } else {
+    Val = AsmReadMsr64 (MsrIndex);
+  }
+
+  return Val;
+}
+
+/**
+  Write to MSR.
+
+  @param  MsrIndex  Index of the MSR to write to
+  @param  Value     Value to be written to the MSR
+
+  @return Value
+
+**/
+UINT64
+LocalApicWriteMsrReg64 (
+  IN UINT32  MsrIndex,
+  IN UINT64  Value
+  )
+{
+  UINT64  Status;
+
+  if (AccessMsrTdxCall (MsrIndex)) {
+    Status = TdVmCall (TDVMCALL_WRMSR, (UINT64)MsrIndex, Value, 0, 0, 0);
+    if (Status != 0) {
+      TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+    }
+  } else {
+    AsmWriteMsr64 (MsrIndex, Value);
+  }
+
+  return Value;
+}
+
+/**
+  Read MSR value.
+
+  @param  MsrIndex  Index of the MSR to read
+  @retval 32-bit    Value of MSR.
+
+**/
+UINT32
+LocalApicReadMsrReg32 (
+  IN UINT32  MsrIndex
+  )
+{
+  return (UINT32)LocalApicReadMsrReg64 (MsrIndex);
+}
+
+/**
+  Write to MSR.
+
+  @param  MsrIndex  Index of the MSR to write to
+  @param  Value     Value to be written to the MSR
+
+  @return Value
+
+**/
+UINT32
+LocalApicWriteMsrReg32 (
+  IN UINT32  MsrIndex,
+  IN UINT32  Value
+  )
+{
+  return (UINT32)LocalApicWriteMsrReg64 (MsrIndex, Value);
+}
+
 /**
   Determine if the CPU supports the Local APIC Base Address MSR.
 
@@ -78,7 +222,7 @@ GetLocalApicBaseAddress (
     return PcdGet32 (PcdCpuLocalApicBaseAddress);
   }
 
-  ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+  ApicBaseMsr.Uint64 = LocalApicReadMsrReg64 (MSR_IA32_APIC_BASE);
 
   return (UINTN)(LShiftU64 ((UINT64)ApicBaseMsr.Bits.ApicBaseHi, 32)) +
          (((UINTN)ApicBaseMsr.Bits.ApicBase) << 12);
@@ -109,12 +253,12 @@ SetLocalApicBaseAddress (
     return;
   }
 
-  ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+  ApicBaseMsr.Uint64 = LocalApicReadMsrReg64 (MSR_IA32_APIC_BASE);
 
   ApicBaseMsr.Bits.ApicBase   = (UINT32)(BaseAddress >> 12);
   ApicBaseMsr.Bits.ApicBaseHi = (UINT32)(RShiftU64 ((UINT64)BaseAddress, 32));
 
-  AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
+  LocalApicWriteMsrReg64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
 }
 
 /**
@@ -154,7 +298,7 @@ ReadLocalApicReg (
     ASSERT (MmioOffset != XAPIC_ICR_HIGH_OFFSET);
 
     MsrIndex = (UINT32)(MmioOffset >> 4) + X2APIC_MSR_BASE_ADDRESS;
-    return AsmReadMsr32 (MsrIndex);
+    return LocalApicReadMsrReg32 (MsrIndex);
   }
 }
 
@@ -203,7 +347,7 @@ WriteLocalApicReg (
     // Use memory fence here to force the serializing semantics to be consisent with xAPIC mode.
     //
     MemoryFence ();
-    AsmWriteMsr32 (MsrIndex, Value);
+    LocalApicWriteMsrReg32 (MsrIndex, Value);
   }
 }
 
@@ -309,7 +453,7 @@ GetApicMode (
     return LOCAL_APIC_MODE_XAPIC;
   }
 
-  ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+  ApicBaseMsr.Uint64 = LocalApicReadMsrReg64 (MSR_IA32_APIC_BASE);
   //
   // Local APIC should have been enabled
   //
@@ -354,9 +498,9 @@ SetApicMode (
       case LOCAL_APIC_MODE_XAPIC:
         break;
       case LOCAL_APIC_MODE_X2APIC:
-        ApicBaseMsr.Uint64    = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+        ApicBaseMsr.Uint64    = LocalApicReadMsrReg64 (MSR_IA32_APIC_BASE);
         ApicBaseMsr.Bits.EXTD = 1;
-        AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
+        LocalApicWriteMsrReg64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
         break;
       default:
         ASSERT (FALSE);