[PATCH v3 0/2] OvmfPkg: broadcast SMIs and dynamically revert to traditional AP sync mode

[Laszlo Ersek <lersek@redhat.com>]

Previous version (v2):
<https://lists.01.org/pipermail/edk2-devel/2016-November/005003.html>.

In this version (again), OVMF negotiates the broadcast SMI feature with
QEMU dynamically. If the feature is available, OVMF selects it, and also
re-sets the UefiCpuPkg PCDs that are related to BSP-AP synchronization
to their "UefiCpuPkg.dec" defaults.

The difference relative to v2 is that for the SMI features, QEMU gained
a dedicated fw_cfg-based negotiation interface, replacing the previously
proposed (somewhat ad-hoc) ICH9_APM_STS-based interface. The QEMU
commits implementing and documenting the new interface are listed in
patch #2. (But, I also commented patch #2 heavily.)

Patch for patch:

- v2 1/4 was committed separately (b43dd22981b7,
  "UefiCpuPkg/PiSmmCpuDxeSmm: dynamic PcdCpuSmmApSyncTimeout,
  PcdCpuSmmSyncMode", 2016-11-17),

- v2 2/4 is now carried forward without changes, as patch #1 (I've
  picked up Jordan's R-b),

- the rest of v2 is replaced with patch #2.

I formatted this series with 7 lines of context, to make it an easier
read.

Repo:   https://github.com/lersek/edk2/
Branch: broadcast_smi_v3
Ref:    https://bugzilla.tianocore.org/show_bug.cgi?id=230

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

Thanks,
Laszlo

Laszlo Ersek (2):
  OvmfPkg: dynamic defaults for PcdCpuSmmApSyncTimeout,
    PcdCpuSmmSyncMode
  OvmfPkg/SmmControl2Dxe: select broadcast SMI if available

 OvmfPkg/OvmfPkgIa32.dsc                   |   7 +-
 OvmfPkg/OvmfPkgIa32X64.dsc                |   7 +-
 OvmfPkg/OvmfPkgX64.dsc                    |   7 +-
 OvmfPkg/SmmControl2Dxe/SmmControl2Dxe.inf |   8 +
 OvmfPkg/SmmControl2Dxe/SmiFeatures.h      |  49 +++
 OvmfPkg/SmmControl2Dxe/SmiFeatures.c      | 324 ++++++++++++++++++++
 OvmfPkg/SmmControl2Dxe/SmmControl2Dxe.c   |  21 ++
 7 files changed, 417 insertions(+), 6 deletions(-)
 create mode 100644 OvmfPkg/SmmControl2Dxe/SmiFeatures.h
 create mode 100644 OvmfPkg/SmmControl2Dxe/SmiFeatures.c

-- 
2.9.3