From 8d9698ecf82a82ded2ce5d5e13d958d8e1c532a1 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Fri, 6 Nov 2020 11:53:07 -0600
Subject: [PATCH] OvmfPkg/VmgExitLib: Set the SwScratch valid bit for IOIO
 events

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

All fields that are set in the GHCB should have their associated bit in
the GHCB ValidBitmap field set. Add support to set the bit for the scratch
area field (SwScratch).

Fixes: 0020157a9825e5f5784ff014044f11c0558c92fe
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>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f817d034cea37fa78e00e86f61c3445f1208226d.1604685192.git.thomas.lendacky@amd.com>
---
 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
index 7d14341d59..e5f14035b0 100644
--- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
@@ -1233,6 +1233,7 @@ IoioExit (
       }
 
       Ghcb->SaveArea.SwScratch = (UINT64) Ghcb->SharedBuffer;
+      VmgSetOffsetValid (Ghcb, GhcbSwScratch);
       Status = VmgExit (Ghcb, SVM_EXIT_IOIO_PROT, ExitInfo1, ExitInfo2);
       if (Status != 0) {
         return Status;