[PATCH v5 2/4] OvmfPkg/VmgExitLib: Add support for hypercalls with SEV-ES.

["Ashish Kalra" <ashish.kalra@amd.com>]

From: Ashish Kalra <ashish.kalra@amd.com>

Make the VC handler hypercall aware by adding support
to compare the hypercall number and add the additional
register values used by hypercall in the GHCB.

Also mark the SEC GHCB page (that is mapped as
unencrypted in ResetVector code) in the hypervisor
guest page status tracking.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
index 41b0c8cc53..7f69bfab5f 100644
--- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
@@ -1171,6 +1171,15 @@ VmmCallExit (
   Ghcb->SaveArea.Cpl = (UINT8) (Regs->Cs & 0x3);
   VmgSetOffsetValid (Ghcb, GhcbCpl);
 
+  if (Regs->Rax == KVM_HC_MAP_GPA_RANGE) {
+    Ghcb->SaveArea.Rbx = Regs->Rbx;
+    VmgSetOffsetValid (Ghcb, GhcbRbx);
+    Ghcb->SaveArea.Rcx = Regs->Rcx;
+    VmgSetOffsetValid (Ghcb, GhcbRcx);
+    Ghcb->SaveArea.Rdx = Regs->Rdx;
+    VmgSetOffsetValid (Ghcb, GhcbRdx);
+  }
+
   Status = VmgExit (Ghcb, SVM_EXIT_VMMCALL, 0, 0);
   if (Status != 0) {
     return Status;
-- 
2.17.1