From 557973a9efb3bf51bc4c770fb18f3d42071eac30 Mon Sep 17 00:00:00 2001
From: Ashish Kalra <ashish.kalra@amd.com>
Date: Tue, 5 Apr 2022 16:27:26 +0000
Subject: [PATCH 14/20] OvmfPkg/VmgExitLib: Encryption state change hypercall
 support in VC handler

cherry-picked from https://patchew.org/EDK2/cover.1629380011.git.ashish.kalra@amd.com .

Make the #VC handler aware of the page encryption state
change hypercall by adding support to check KVM_HC_MAP_GPA_RANGE
hypercall and add the additional register values used by
hypercall in the GHCB.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 OvmfPkg/Library/CcExitLib/CcExitVcHandler.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
index 0fc30f7..5c9a908 100644
--- a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
+++ b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
@@ -677,6 +677,19 @@ VmmCallExit (
   Ghcb->SaveArea.Cpl = (UINT8)(Regs->Cs & 0x3);
   CcExitVmgSetOffsetValid (Ghcb, GhcbCpl);
 
+  if (Regs->Rax == KVM_HC_MAP_GPA_RANGE) {
+    //
+    // KVM_HC_MAP_GPA_RANGE hypercall requires these
+    // extra registers.
+    //
+    Ghcb->SaveArea.Rbx = Regs->Rbx;
+    CcExitVmgSetOffsetValid (Ghcb, GhcbRbx);
+    Ghcb->SaveArea.Rcx = Regs->Rcx;
+    CcExitVmgSetOffsetValid (Ghcb, GhcbRcx);
+    Ghcb->SaveArea.Rdx = Regs->Rdx;
+    CcExitVmgSetOffsetValid (Ghcb, GhcbRdx);
+  }
+
   Status = CcExitVmgExit (Ghcb, SVM_EXIT_VMMCALL, 0, 0);
   if (Status != 0) {
     return Status;
-- 
2.41.1