[PATCH v2 01/11] MdePkg, OvmfPkg: Clean up GHCB field offsets and save area

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

From: Tom Lendacky <thomas.lendacky@amd.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3008

Use OFFSET_OF () and sizeof () to calculate the GHCB register field
offsets instead of hardcoding the values in the GHCB_REGISTER enum.
Rename GHCB_REGISTER to GHCB_QWORD_OFFSET to more appropriately describe
the enum. While redefining the values, only include (and add) fields that
are used per the GHCB specification.

Also, remove the DR7 field from the GHCB_SAVE_AREA structure since it is
not used/defined in the GHCB specification and then rename the reserved
fields as appropriate.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 MdePkg/Include/Register/Amd/Ghcb.h            | 40 +++++++-------------
 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c |  4 +-
 2 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/MdePkg/Include/Register/Amd/Ghcb.h b/MdePkg/Include/Register/Amd/Ghcb.h
index 54a80da0f6d7..93fb6e3cb0fc 100644
--- a/MdePkg/Include/Register/Amd/Ghcb.h
+++ b/MdePkg/Include/Register/Amd/Ghcb.h
@@ -82,35 +82,10 @@
 #define IOIO_SEG_DS         (BIT11 | BIT10)
 
 
-typedef enum {
-  GhcbCpl              = 25,
-  GhcbRflags           = 46,
-  GhcbRip,
-  GhcbRsp              = 59,
-  GhcbRax              = 63,
-  GhcbRcx              = 97,
-  GhcbRdx,
-  GhcbRbx,
-  GhcbRbp              = 101,
-  GhcbRsi,
-  GhcbRdi,
-  GhcbR8,
-  GhcbR9,
-  GhcbR10,
-  GhcbR11,
-  GhcbR12,
-  GhcbR13,
-  GhcbR14,
-  GhcbR15,
-  GhcbXCr0             = 125,
-} GHCB_REGISTER;
-
 typedef PACKED struct {
   UINT8                  Reserved1[203];
   UINT8                  Cpl;
-  UINT8                  Reserved2[148];
-  UINT64                 Dr7;
-  UINT8                  Reserved3[144];
+  UINT8                  Reserved8[300];
   UINT64                 Rax;
   UINT8                  Reserved4[264];
   UINT64                 Rcx;
@@ -136,6 +111,19 @@ typedef PACKED struct {
   UINT32                 GhcbUsage;
 } GHCB;
 
+typedef enum {
+  GhcbCpl          = OFFSET_OF (GHCB, SaveArea.Cpl) / sizeof (UINT64),
+  GhcbRax          = OFFSET_OF (GHCB, SaveArea.Rax) / sizeof (UINT64),
+  GhcbRbx          = OFFSET_OF (GHCB, SaveArea.Rbx) / sizeof (UINT64),
+  GhcbRcx          = OFFSET_OF (GHCB, SaveArea.Rcx) / sizeof (UINT64),
+  GhcbRdx          = OFFSET_OF (GHCB, SaveArea.Rdx) / sizeof (UINT64),
+  GhcbXCr0         = OFFSET_OF (GHCB, SaveArea.XCr0) / sizeof (UINT64),
+  GhcbSwExitCode   = OFFSET_OF (GHCB, SaveArea.SwExitCode) / sizeof (UINT64),
+  GhcbSwExitInfo1  = OFFSET_OF (GHCB, SaveArea.SwExitInfo1) / sizeof (UINT64),
+  GhcbSwExitInfo2  = OFFSET_OF (GHCB, SaveArea.SwExitInfo2) / sizeof (UINT64),
+  GhcbSwScratch    = OFFSET_OF (GHCB, SaveArea.SwScratch) / sizeof (UINT64),
+} GHCB_QWORD_OFFSET;
+
 typedef union {
   struct {
     UINT32  Lower32Bits;
diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
index 8e42b305e83c..c5484a3f478c 100644
--- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
@@ -153,7 +153,7 @@ STATIC
 BOOLEAN
 GhcbIsRegValid (
   IN GHCB                *Ghcb,
-  IN GHCB_REGISTER       Reg
+  IN GHCB_QWORD_OFFSET   Reg
   )
 {
   UINT32  RegIndex;
@@ -179,7 +179,7 @@ STATIC
 VOID
 GhcbSetRegValid (
   IN OUT GHCB                *Ghcb,
-  IN     GHCB_REGISTER       Reg
+  IN     GHCB_QWORD_OFFSET   Reg
   )
 {
   UINT32  RegIndex;
-- 
2.28.0