[PATCH 00/14] OvmfPkg: add the Variable PEIM, defragment the UEFI memmap

[Laszlo Ersek <lersek@redhat.com>]

This series implements the ideas discussed in the thread

  [edk2] memory type information HOB / UEFI memmap defrag
  https://lists.01.org/pipermail/edk2-devel/2017-February/007576.html

I'm seeing good results, with approx. 20-24 UEFI memmap entries removed.

The benefits of the patch set are automatically enabled for SMM_REQUIRE
builds.

For non-SMM builds (which are the default), another build flag is being
introduced, namely MEM_VARSTORE_EMU_ENABLE. This build flag controls the
reserved memory / NvVars file based variable emulation. It remains
enabled by default (keeping the current status quo). For benefiting from
the Variable PEIM and the dependent UEFI memmap defragmentation,
MEM_VARSTORE_EMU_ENABLE has to be *disabled*. There are two reasons for
this:

- The PEI phase FTW and Variable modules need immediate (at-startup)
  access to the variable store, but the reserved memory based emulation
  depends on dynamic allocation, plus moving the dynamic pflash
  detection to PEI is out of question.

- Even more importantly, reading actual variable contents from the
  non-pflash varstore would require, in PEI, similar hackery that
  currently happens in BDS -- that's not going to happen.

In fact one of the longer term goals with MEM_VARSTORE_EMU_ENABLE is to
identify what we'll rip out once we finally decide to drop the reserved
memory / NvVars file based emulation.

A summary of build modes:

* default build: works as before, with the Variable PEIM and UEFI memmap
  defragmentation remaining unavailable.

* -D SMM_REQUIRE: works as before, with the Variable PEIM and UEFI
  memmap defragmentation enabled.

  As a reminder, this build is inherently incompatible with QEMU's
  "-bios" and "-L" parameters, which will trigger the ASSERT() in
  QemuFlashInitialize()
  [OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c], added in commit
  b963ec494c48 ("OvmfPkg: QemuFlashFvbServicesRuntimeDxe: adhere to -D
  SMM_REQUIRE", 2015-11-30).

* -D MEM_VARSTORE_EMU_ENABLE=FALSE: eliminates the reserved memory /
  NvVars based variable emulation, turns pflash into a hard requirement,
  and enables the Variable PEIM and the UEFI memmap defragmentation.

  If such a build is executed with -bios or -L, then the FTW and
  Variable PEIMs will temporarily see a well-formed, but empty varstore
  (straight from "OvmfPkg/VarStore.fdf.inc"), and then
  QemuFlashFvbServicesRuntimeDxe will trip a new ASSERT(), in patch #6,
  that is similar to the one added in commit b963ec494c48 (see above).

Anatomy of the series:

* Patches 01 through 04 clean up some innocent warts I noticed while
  working on the feature.

* Patches 05 through 07 introduce the new build option and its basic
  effect, the disabling of reserved memory based variable emulation.

* Patches 08 through 12 include the FTW and Variable PEIMs.

* Patch 13 enables UEFI memmap defragmentation.

* Patch 14 updates the README file.

The variable PEIM was independently requested in
<https://bugzilla.tianocore.org/show_bug.cgi?id=386> earlier, but
without a good upstreamable use case, I disagreed with its inclusion.
The memmap defragmentation is a good use case however.

Also, I didn't lie about "downstream pressure" in my previous patch set;
I wrote this one at Sunday/Monday night (and now it's Tues/Wed night).
So one could consider this personal diligence. :)

The series conforms to the multi-line function call syntax outlined in
<https://bugzilla.tianocore.org/show_bug.cgi?id=425>.

Repo:   https://github.com/lersek/edk2.git
Branch: memmap_defrag

CC: Jordan Justen <jordan.l.justen@intel.com>

Thanks
Laszlo

Laszlo Ersek (14):
  OvmfPkg/EmuVariableFvbRuntimeDxe: always format an auth varstore
    header
  OvmfPkg: remove gUefiOvmfPkgTokenSpaceGuid.PcdSecureBootEnable
  OvmfPkg/PlatformPei: remove unused PcdVariableStoreSize dependency
  OvmfPkg/PlatformPei: don't allocate reserved mem varstore if
    SMM_REQUIRE
  OvmfPkg: introduce PcdMemVarstoreEmuEnable feature flag
  OvmfPkg/QemuFlashFvbServicesRuntimeDxe: check PcdMemVarstoreEmuEnable
  OvmfPkg: conditionally disable reserved memory varstore emulation at
    build
  OvmfPkg: resolve PcdLib for all PEIMs individually
  OvmfPkg: resolve PcdLib for PEIMs to PeiPcdLib by default
  OvmfPkg: introduce FlashNvStorageAddressLib
  OvmfPkg: include FaultTolerantWritePei and VariablePei
  OvmfPkg/QemuFlashFvbServicesRuntimeDxe: don't set flash PCDs if SMM or
    no-emu
  OvmfPkg/PlatformPei: remedy UEFI memory map fragmentation
  OvmfPkg/README: document MEM_VARSTORE_EMU_ENABLE and memmap defrag

 OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c                                |  79 +---------
 OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.inf                              |   3 -
 OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c   |  53 +++++++
 OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf |  48 +++++++
 OvmfPkg/OvmfPkg.dec                                                   |   7 +-
 OvmfPkg/OvmfPkgIa32.dsc                                               |  43 +++---
 OvmfPkg/OvmfPkgIa32.fdf                                               |   8 +-
 OvmfPkg/OvmfPkgIa32X64.dsc                                            |  43 +++---
 OvmfPkg/OvmfPkgIa32X64.fdf                                            |   8 +-
 OvmfPkg/OvmfPkgX64.dsc                                                |  43 +++---
 OvmfPkg/OvmfPkgX64.fdf                                                |   8 +-
 OvmfPkg/PlatformPei/MemTypeInfo.c                                     | 151 ++++++++++++++++++++
 OvmfPkg/PlatformPei/Platform.c                                        |  28 +---
 OvmfPkg/PlatformPei/Platform.h                                        |   5 +
 OvmfPkg/PlatformPei/PlatformPei.inf                                   |   4 +-
 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesRuntimeDxe.inf      |   1 +
 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesSmm.inf             |   1 +
 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c               |  58 +++++---
 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c                    |   1 +
 OvmfPkg/README                                                        |  10 ++
 20 files changed, 425 insertions(+), 177 deletions(-)
 create mode 100644 OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf
 create mode 100644 OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c
 create mode 100644 OvmfPkg/PlatformPei/MemTypeInfo.c

-- 
2.9.3