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| author | Ray Ni <ray.ni@intel.com> | 2019-08-26 06:27:13 +0800 |
|---|---|---|
| committer | Ray Ni <ray.ni@intel.com> | 2019-09-04 01:00:11 +0800 |
| commit | f64a597d45f9a10c378735baeeaed0c0c42da527 (patch) | |
| tree | 10dc4e29b9158c5e1cf468e037770199aca8cd2e /UefiCpuPkg/UefiCpuPkg.dec | |
| parent | 79186ddcddcabe48eceb58efd296252e3d53b003 (diff) | |
| download | edk2-f64a597d45f9a10c378735baeeaed0c0c42da527.tar.gz edk2-f64a597d45f9a10c378735baeeaed0c0c42da527.tar.bz2 edk2-f64a597d45f9a10c378735baeeaed0c0c42da527.zip | |
UefiCpuPkg: Explain relationship between several SMM PCDs
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@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'UefiCpuPkg/UefiCpuPkg.dec')
| -rw-r--r-- | UefiCpuPkg/UefiCpuPkg.dec | 8 |
1 files changed, 7 insertions, 1 deletions
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 @@ [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 @@ # 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.
|