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authorLaszlo Ersek <lersek@redhat.com>2019-09-20 17:07:43 +0200
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2020-02-05 12:59:32 +0000
commit300aae1180909b9141225d6a67e100fbfacc758f (patch)
tree7a086f8355a7fefb54c98258d44f436ea576806d /OvmfPkg/PlatformPei
parent84b223c18ca41532645e7594067e87d509a3c96f (diff)
downloadedk2-300aae1180909b9141225d6a67e100fbfacc758f.tar.gz
OvmfPkg/SEV: don't manage the lifecycle of the SMRAM at the default SMBASE
When OVMF runs in a SEV guest, the initial SMM Save State Map is (1) allocated as EfiBootServicesData type memory in OvmfPkg/PlatformPei, function AmdSevInitialize(), for preventing unintended information sharing with the hypervisor; (2) decrypted in AmdSevDxe; (3) re-encrypted in OvmfPkg/Library/SmmCpuFeaturesLib, function SmmCpuFeaturesSmmRelocationComplete(), which is called by PiSmmCpuDxeSmm right after initial SMBASE relocation; (4) released to DXE at the same location. The SMRAM at the default SMBASE is a superset of the initial Save State Map. The reserved memory allocation in InitializeRamRegions(), from the previous patch, must override the allocating and freeing in (1) and (4), respectively. (Note: the decrypting and re-encrypting in (2) and (3) are unaffected.) In AmdSevInitialize(), only assert the containment of the initial Save State Map, in the larger area already allocated by InitializeRamRegions(). In SmmCpuFeaturesSmmRelocationComplete(), preserve the allocation of the initial Save State Map into OS runtime, as part of the allocation done by InitializeRamRegions(). Only assert containment. These changes only affect the normal boot path (the UEFI memory map is untouched during S3 resume). Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Jordan Justen <jordan.l.justen@intel.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com> Message-Id: <20200129214412.2361-9-lersek@redhat.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Diffstat (limited to 'OvmfPkg/PlatformPei')
-rw-r--r--OvmfPkg/PlatformPei/AmdSev.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index 2ae8126ccf..e484f4b311 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -9,6 +9,7 @@
//
// The package level header files this module uses
//
+#include <IndustryStandard/Q35MchIch9.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
#include <Library/MemEncryptSevLib.h>
@@ -16,6 +17,7 @@
#include <PiPei.h>
#include <Register/Amd/Cpuid.h>
#include <Register/Cpuid.h>
+#include <Register/Intel/SmramSaveStateMap.h>
#include "Platform.h"
@@ -83,10 +85,22 @@ AmdSevInitialize (
);
ASSERT_RETURN_ERROR (LocateMapStatus);
- BuildMemoryAllocationHob (
- MapPagesBase, // BaseAddress
- EFI_PAGES_TO_SIZE (MapPagesCount), // Length
- EfiBootServicesData // MemoryType
- );
+ if (mQ35SmramAtDefaultSmbase) {
+ //
+ // The initial SMRAM Save State Map has been covered as part of a larger
+ // reserved memory allocation in InitializeRamRegions().
+ //
+ ASSERT (SMM_DEFAULT_SMBASE <= MapPagesBase);
+ ASSERT (
+ (MapPagesBase + EFI_PAGES_TO_SIZE (MapPagesCount) <=
+ SMM_DEFAULT_SMBASE + MCH_DEFAULT_SMBASE_SIZE)
+ );
+ } else {
+ BuildMemoryAllocationHob (
+ MapPagesBase, // BaseAddress
+ EFI_PAGES_TO_SIZE (MapPagesCount), // Length
+ EfiBootServicesData // MemoryType
+ );
+ }
}
}