[edk2-devel] [PATCH 4/5] UefiCpuPkg: Explain relationship between several SMM PCDs
Ni, Ray
ray.ni at intel.com
Sun Aug 25 22:45:12 UTC 2019
There are three PCDs that may impact the behavior of each other in
SMM environment:
PcdCpuSmmProfileEnable
PcdHeapGuardPropertyMask in MdeModulePkg
PcdCpuSmmRestrictedMemoryAccess
The patch updates the comments in DEC file to document it.
Signed-off-by: Ray Ni <ray.ni at intel.com>
Cc: Eric Dong <eric.dong at intel.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
---
UefiCpuPkg/UefiCpuPkg.dec | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index 83acd33612..9a03bdd716 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -81,7 +81,8 @@ [Ppis]
[PcdsFeatureFlag]
## Indicates if SMM Profile will be enabled.
# If enabled, instruction executions in and data accesses to memory outside of SMRAM will be logged.
- # It could not be enabled at the same time with SMM static page table feature (PcdCpuSmmStaticPageTable).
+ # In X64 build, it could not be enabled when PcdCpuSmmRestrictedMemoryAccess is TRUE.
+ # In IA32 build, the page table memory is not marked as read-only when it is enabled.
# This PCD is only for validation purpose. It should be set to false in production.<BR><BR>
# TRUE - SMM Profile will be enabled.<BR>
# FALSE - SMM Profile will be disabled.<BR>
@@ -285,6 +286,11 @@ [PcdsFixedAtBuild.X64, PcdsPatchableInModule.X64, PcdsDynamic.X64, PcdsDynamicEx
# The PCD value is considered as constantly TRUE in IA32 platforms.
# When the PCD value is TRUE, page table is initialized to cover all memory spaces
# and the memory occupied by page table is protected by page table itself as read-only.
+ # In X64 build, it cannot be enabled at the same time with SMM profile feature (PcdCpuSmmProfileEnable).
+ # In X64 build, it could not be enabled also at the same time with heap guard feature for SMM
+ # (PcdHeapGuardPropertyMask in MdeModulePkg).
+ # In IA32 build, page table memory is not marked as read-only when either SMM profile feature (PcdCpuSmmProfileEnable)
+ # or heap guard feature for SMM (PcdHeapGuardPropertyMask in MdeModulePkg) is enabled.
# TRUE - Access to non-SMRAM memory is restricted to reserved, runtime and ACPI NVS type after SmmReadyToLock.<BR>
# FALSE - Access to any type of non-SMRAM memory after SmmReadyToLock is allowed.<BR>
# @Prompt Access to non-SMRAM memory is restricted to reserved, runtime and ACPI NVS type after SmmReadyToLock.
--
2.21.0.windows.1
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