From d511d6e0e7a9ffa960afb275c28093bfe41e42ad Mon Sep 17 00:00:00 2001
From: Michael Kubacki <michael.a.kubacki@intel.com>
Date: Mon, 14 Oct 2019 10:14:24 -0700
Subject: [PATCH] OvmfPkg: Disable variable runtime cache

Sets gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache
to FALSE in OvmfPkgIa32.dsc, OvmfPkgIa32X64.dsc, and OvmfPkgX64.dsc
so that when SMM_REQUIRE is TRUE, the SMM variable driver will not
use the runtime variable cache.

This is done for OvmfPkg because it currently depends upon a SMM
variable GetVariable ()implementation as a simple method to exercise
the SMM driver stack. This allows the following commands to be used
for variables such as Boot####, BootOrder, and BootNext to test SMM
timing and stability differences on the BSP (e.g. CPU#0) vs an
AP (e.g. CPU#1).
 # taskset -c 0 efibootmgr
 # taskset -c 1 efibootmgr

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 OvmfPkg/OvmfPkgIa32.dsc    | 1 +
 OvmfPkg/OvmfPkgIa32X64.dsc | 1 +
 OvmfPkg/OvmfPkgX64.dsc     | 1 +
 3 files changed, 3 insertions(+)

diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 05bb6ae136..d350b75630 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -431,6 +431,7 @@
 !if $(SMM_REQUIRE) == TRUE
   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE
 !endif
 
 [PcdsFixedAtBuild]
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 4a75a0332e..1ef82cafe4 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -436,6 +436,7 @@
 !if $(SMM_REQUIRE) == TRUE
   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE
 !endif
 
 [PcdsFixedAtBuild]
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index ed54181180..232815c08e 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -436,6 +436,7 @@
 !if $(SMM_REQUIRE) == TRUE
   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE
 !endif
 
 [PcdsFixedAtBuild]
-- 
2.39.2