From: Brijesh Singh <brijesh.singh@amd.com>
Date: Thu, 5 Oct 2017 20:16:42 +0000 (-0500)
Subject: OvmfPkg/PlatformPei: DENY_EXECUTE_ON_SECURITY_VIOLATION when SEV is active
X-Git-Tag: edk2-stable201903~3207
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=6041ac65ae879389f3ab5c0699f916d3e71c97fe

OvmfPkg/PlatformPei: DENY_EXECUTE_ON_SECURITY_VIOLATION when SEV is active

The following commit:

1fea9ddb4e3f OvmfPkg: execute option ROM images regardless of Secure Boot

sets the OptionRomImageVerificationPolicy to ALWAYS_EXECUTE the expansion
ROMs attached to the emulated PCI devices. A expansion ROM constitute
another channel through which a cloud provider (i.e hypervisor) can
inject a code in guest boot flow to compromise it.

When SEV is enabled, the bios code has been verified by the guest owner
via the SEV guest launch sequence before its executed. When secure boot,
is enabled, lets make sure that we do not allow guest bios to execute a
code which is not signed by the guest owner.

Fixes: https://bugzilla.tianocore.org/show_bug.cgi?id=728
Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---

diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 92e943d4a0..7fb557b7c9 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -483,10 +483,6 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStackSize|0x4000
 !endif
 
-!if $(SECURE_BOOT_ENABLE) == TRUE
-  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
-!endif
-
   # IRQs 5, 9, 10, 11 are level-triggered
   gPcAtChipsetPkgTokenSpaceGuid.Pcd8259LegacyModeEdgeLevel|0x0E20
 
@@ -544,6 +540,11 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout|100000
 !endif
 
+!if $(SECURE_BOOT_ENABLE) == TRUE
+  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
+!endif
+
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform.
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 7f9220ccb9..4bcbddb957 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -489,10 +489,6 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStackSize|0x4000
 !endif
 
-!if $(SECURE_BOOT_ENABLE) == TRUE
-  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
-!endif
-
   # IRQs 5, 9, 10, 11 are level-triggered
   gPcAtChipsetPkgTokenSpaceGuid.Pcd8259LegacyModeEdgeLevel|0x0E20
 
@@ -552,6 +548,11 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout|100000
 !endif
 
+!if $(SECURE_BOOT_ENABLE) == TRUE
+  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
+!endif
+
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform.
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 36c60fc19c..e52a3bd4db 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -488,10 +488,6 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStackSize|0x4000
 !endif
 
-!if $(SECURE_BOOT_ENABLE) == TRUE
-  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
-!endif
-
   # IRQs 5, 9, 10, 11 are level-triggered
   gPcAtChipsetPkgTokenSpaceGuid.Pcd8259LegacyModeEdgeLevel|0x0E20
 
@@ -551,6 +547,11 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout|100000
 !endif
 
+!if $(SECURE_BOOT_ENABLE) == TRUE
+  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy|0x00
+!endif
+
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform.
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index 26f7c3fdbb..1539e5b5cd 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -59,4 +59,11 @@ AmdSevInitialize (
   ASSERT_RETURN_ERROR (PcdStatus);
 
   DEBUG ((DEBUG_INFO, "SEV is enabled (mask 0x%lx)\n", EncryptionMask));
+
+  //
+  // Set Pcd to Deny the execution of option ROM when security
+  // violation.
+  //
+  PcdStatus = PcdSet32S (PcdOptionRomImageVerificationPolicy, 0x4);
+  ASSERT_RETURN_ERROR (PcdStatus);
 }
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf
index 16a8db7b0b..de7434d93d 100644
--- a/OvmfPkg/PlatformPei/PlatformPei.inf
+++ b/OvmfPkg/PlatformPei/PlatformPei.inf
@@ -41,6 +41,7 @@
   IntelFrameworkModulePkg/IntelFrameworkModulePkg.dec
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
+  SecurityPkg/SecurityPkg.dec
   UefiCpuPkg/UefiCpuPkg.dec
   OvmfPkg/OvmfPkg.dec
 
@@ -96,6 +97,7 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdPropertiesTableEnable
   gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable
   gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask
+  gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy
   gUefiCpuPkgTokenSpaceGuid.PcdCpuLocalApicBaseAddress
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber
   gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds