From f714fd67f296c2ff5bf2809dc3382d2fa2631dee Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Fri, 6 Nov 2020 11:53:10 -0600
Subject: [PATCH] OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Set the SwScratch
 valid bit

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: 437eb3f7a8db7681afe0e6064d3a8edb12abb766
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <cc8c8449740d2be0b287e6c69d48bf6cb067c7d8.1604685192.git.thomas.lendacky@amd.com>
---
 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashDxe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashDxe.c b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashDxe.c
index 565383ee26..f9b21b5413 100644
--- a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashDxe.c
+++ b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashDxe.c
@@ -66,6 +66,7 @@ QemuFlashPtrWrite (
     VmgInit (Ghcb);
     Ghcb->SharedBuffer[0] = Value;
     Ghcb->SaveArea.SwScratch = (UINT64) (UINTN) Ghcb->SharedBuffer;
+    VmgSetOffsetValid (Ghcb, GhcbSwScratch);
     VmgExit (Ghcb, SVM_EXIT_MMIO_WRITE, (UINT64) (UINTN) Ptr, 1);
     VmgDone (Ghcb);
   } else {