[PATCH v3 0/5] Abstract allocation of PEI accessible memory

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

At the moment, FirmwarePerformanceTableDataDxe or DxeCorePerformanceLib
are unusable on systems such as AMD Seattle, because they unconditionally
attempt to allocate memory below 4 GB, and ASSERT() if this fails. On AMD
Seattle, no 32-bit addressable DRAM exists, and so the driver will always
assert, and crash a running DEBUG build.

The reason for this is that some platforms (i.e., X64 builds consisting of
a 32-bit PEI stage and 64-bit remaining stages) require these allocations
to be below 4 GB, and for some reason, open coding this practice throughout
the code without regard for other architectures has been regarded as an
acceptable approach.

Instead, I would like to propose the approach implemented in this series:
- create an abstracted AllocatePeiAccessiblePages() routine in DxeServicesLib
  that simply allocates pages from any region on all architectures except X64,
  and allocate below 4 GB for X64
- update the various call sites with calls to this new function.

The above is implemented in patches #3 - #6. Patches #1 and #2 are fixes
for issues that I observed in ArmVirtPkg and OvmfPkg while working on
these patches.

Code can be found here:
https://github.com/ardbiesheuvel/edk2/tree/allocate-pei-v3

Changes since v2:
- move AllocatePeiAccessiblePages() to a separate .c file, and create a special
  X64 version (#3)
- add back ZeroMem() call to #4
- add Laszlo's ack to #4 - #5 (but not to #3 since it has been updated)

Changes since v1:
- add Laszlo's ack to #1 - #2
- move EfiAllocatePeiPages() to DxeServicesLib and drop Efi prefix
- update implementation to take EfiFreeMemoryTop into account when built
  for X64

Ard Biesheuvel (5):
  OvmfPkg/PlatformBootManagerLib: add missing report status code call
  ArmVirtPkg/PlatformBootManagerLib: add missing report status code call
  MdePkg/DxeServicesLib: introduce AllocatePeiAccessiblePages routine
  MdeModulePkg/DxeCorePerformanceLib: use AllocatePeiAccessiblePages
  MdeModulePkg/FirmwarePerformanceDataTableDxe: use
    AllocatePeiAccessiblePages

 .../PlatformBootManagerLib.inf                |  1 +
 .../PlatformBootManagerLib/QemuKernel.c       |  4 ++
 .../DxeCorePerformanceLib.c                   | 48 ++-----------
 .../FirmwarePerformanceDxe.c                  | 51 +++-----------
 .../FirmwarePerformanceDxe.inf                |  1 +
 MdePkg/Include/Library/DxeServicesLib.h       | 23 ++++++-
 MdePkg/Library/DxeServicesLib/Allocate.c      | 54 +++++++++++++++
 .../Library/DxeServicesLib/DxeServicesLib.inf | 11 ++-
 MdePkg/Library/DxeServicesLib/X64/Allocate.c  | 69 +++++++++++++++++++
 .../PlatformBootManagerLib.inf                |  1 +
 .../PlatformBootManagerLib/QemuKernel.c       |  4 ++
 11 files changed, 182 insertions(+), 85 deletions(-)
 create mode 100644 MdePkg/Library/DxeServicesLib/Allocate.c
 create mode 100644 MdePkg/Library/DxeServicesLib/X64/Allocate.c

-- 
2.17.0