[PATCH RFC v2 04/28] MdePkg: Define the Page State Change VMGEXIT structures

["Brijesh Singh" <brijesh.singh@amd.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

The Page State Change NAE exit will be used by the SEV-SNP guest to
request a page state change using the GHCB protocol. See the GHCB
spec section 4.1.6 and 2.3.1 for more detail on the structure
definitions.

Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 MdePkg/Include/Register/Amd/Fam17Msr.h | 15 ++++++++++
 MdePkg/Include/Register/Amd/Ghcb.h     | 29 ++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/MdePkg/Include/Register/Amd/Fam17Msr.h b/MdePkg/Include/Register/Amd/Fam17Msr.h
index e19bd04b6c..432cee2feb 100644
--- a/MdePkg/Include/Register/Amd/Fam17Msr.h
+++ b/MdePkg/Include/Register/Amd/Fam17Msr.h
@@ -58,6 +58,19 @@ typedef union {
     UINT64  GuestFrameNumber:52;
   } GhcbGpaRegister;
 
+  struct {
+    UINT64 Function:12;
+    UINT64 GuestFrameNumber:40;
+    UINT64 Operation:4;
+    UINT64 Reserved:8;
+  } SnpPageStateChangeRequest;
+
+  struct {
+    UINT32 Function:12;
+    UINT32 Reserved:20;
+    UINT32 ErrorCode;
+  } SnpPageStateChangeResponse;
+
   VOID    *Ghcb;
 
   UINT64  GhcbPhysicalAddress;
@@ -69,6 +82,8 @@ typedef union {
 #define GHCB_INFO_CPUID_RESPONSE           5
 #define GHCB_INFO_GHCB_GPA_REGISTER_REQUEST   18
 #define GHCB_INFO_GHCB_GPA_REGISTER_RESPONSE  19
+#define GHCB_INFO_SNP_PAGE_STATE_CHANGE_REQUEST   20
+#define GHCB_INFO_SNP_PAGE_STATE_CHANGE_RESPONSE  21
 #define GHCB_HYPERVISOR_FEATURES_REQUEST   128
 #define GHCB_HYPERVISOR_FEATURES_RESPONSE  129
 #define GHCB_INFO_TERMINATE_REQUEST        256
diff --git a/MdePkg/Include/Register/Amd/Ghcb.h b/MdePkg/Include/Register/Amd/Ghcb.h
index 2d64a4c28f..1e7c0daed3 100644
--- a/MdePkg/Include/Register/Amd/Ghcb.h
+++ b/MdePkg/Include/Register/Amd/Ghcb.h
@@ -54,6 +54,7 @@
 #define SVM_EXIT_NMI_COMPLETE   0x80000003ULL
 #define SVM_EXIT_AP_RESET_HOLD  0x80000004ULL
 #define SVM_EXIT_AP_JUMP_TABLE  0x80000005ULL
+#define SVM_EXIT_SNP_PAGE_STATE_CHANGE    0x80000010ULL
 #define SVM_EXIT_HYPERVISOR_FEATURES  0x8000FFFDULL
 #define SVM_EXIT_UNSUPPORTED    0x8000FFFFULL
 
@@ -160,4 +161,32 @@ typedef union {
 #define GHCB_HV_FEATURES_SNP_AP_CREATE                    (GHCB_HV_FEATURES_SNP | BIT1)
 #define GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION         (GHCB_HV_FEATURES_SNP_AP_CREATE | BIT2)
 #define GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION_TIMER   (GHCB_HV_FEATURES_SNP_RESTRICTED_INJECTION | BIT3)
+
+// SNP Page State Change
+#define SNP_PAGE_STATE_MAX_NPAGES           4095
+#define SNP_PAGE_STATE_MAX_ENTRY            253
+#define SNP_PAGE_STATE_PRIVATE              1
+#define SNP_PAGE_STATE_SHARED               2
+#define SNP_PAGE_STATE_PSMASH               3
+#define SNP_PAGE_STATE_UNSMASH              4
+
+typedef PACKED struct {
+  UINT64  CurrentPage:12;
+  UINT64  GuestFrameNumber:40;
+  UINT64  Op:4;
+  UINT64  PageSize:1;
+  UINT64  Rsvd: 7;
+} SNP_PAGE_STATE_ENTRY;
+
+typedef PACKED struct {
+  UINT16 CurrentEntry;
+  UINT16 EndEntry;
+  UINT32 Rsvd;
+} SNP_PAGE_STATE_HEADER;
+
+typedef struct {
+  SNP_PAGE_STATE_HEADER  Header;
+  SNP_PAGE_STATE_ENTRY   Entry[SNP_PAGE_STATE_MAX_ENTRY];
+} SNP_PAGE_STATE_CHANGE_INFO;
+
 #endif
-- 
2.17.1