Re: [PATCH v1] UefiCpuPkg: Cpu feature data stored in memory may be migrated

["Dong, Eric" <eric.dong@intel.com>]

Hi,

Can you help to explain more why PeiAllocatePages does not have the problem while PeiAllocatePool has?

Thanks,
Eric

-----Original Message-----
From: Lou, Yun <yun.lou@intel.com> 
Sent: Wednesday, September 29, 2021 7:53 PM
To: devel@edk2.groups.io
Cc: Lou, Yun <yun.lou@intel.com>; Ni, Ray <ray.ni@intel.com>; Dong, Eric <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>; Kumar, Rahul1 <rahul1.kumar@intel.com>
Subject: [PATCH v1] UefiCpuPkg: Cpu feature data stored in memory may be migrated

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3634

The memory allocated through "PeiAllocatePool" is located in HOB, and
in DXE phase, the HOB will be migrated to a different location.
After the migration, the data stored in the HOB stays the same, but the
address of pointer to the memory(such as the pointers in ACPI_CPU_DATA
structure) changes, which may cause "PiSmmCpuDxeSmm" driver can't find
the memory(the pointers in ACPI_CPU_DATA structure) that allocated in
"PeiRegisterCpuFeaturesLib", so use "PeiAllocatePages" to allocate
memory instead.

Signed-off-by: Jason Lou <yun.lou@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
---
 UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
index 6e2ab79518..e9eba64914 100644
--- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
+++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
@@ -153,7 +153,7 @@ CpuInitDataInitialize (
   CpuFeaturesData->AcpiCpuData= AcpiCpuData;

 

   CpuStatus = &AcpiCpuData->CpuFeatureInitData.CpuStatus;

-  Location = AllocateZeroPool (sizeof (EFI_CPU_PHYSICAL_LOCATION) * NumberOfCpus);

+  Location = AllocatePages (EFI_SIZE_TO_PAGES (sizeof (EFI_CPU_PHYSICAL_LOCATION) * NumberOfCpus));

   ASSERT (Location != NULL);

   AcpiCpuData->CpuFeatureInitData.ApLocation = (EFI_PHYSICAL_ADDRESS)(UINTN)Location;

 

@@ -205,11 +205,11 @@ CpuInitDataInitialize (
   //

   // Collect valid core count in each package because not all cores are valid.

   //

-  ThreadCountPerPackage = AllocateZeroPool (sizeof (UINT32) * CpuStatus->PackageCount);

+  ThreadCountPerPackage = AllocatePages (EFI_SIZE_TO_PAGES (sizeof (UINT32) * CpuStatus->PackageCount));

   ASSERT (ThreadCountPerPackage != NULL);

   CpuStatus->ThreadCountPerPackage = (EFI_PHYSICAL_ADDRESS)(UINTN)ThreadCountPerPackage;

 

-  ThreadCountPerCore = AllocateZeroPool (sizeof (UINT8) * CpuStatus->PackageCount * CpuStatus->MaxCoreCount);

+  ThreadCountPerCore = AllocatePages (EFI_SIZE_TO_PAGES (sizeof (UINT8) * CpuStatus->PackageCount * CpuStatus->MaxCoreCount));

   ASSERT (ThreadCountPerCore != NULL);

   CpuStatus->ThreadCountPerCore = (EFI_PHYSICAL_ADDRESS)(UINTN)ThreadCountPerCore;

 

-- 
2.28.0.windows.1