Re: [PATCH v6 0/7] MdeModulePkg: add support for dispatching foreign arch PE/COFF images

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Monday, April 15, 2019 3:52 AM
> To: devel@edk2.groups.io
> Cc: Ard Biesheuvel; Kinney, Michael D; Andrew Fish; Leif Lindholm; Zeng, Star;
> Dong, Eric; Ni, Ray; Gao, Liming; Carsey, Jaben; Shi, Steven; Wang, Jian J; Wu,
> Hao A
> Subject: [PATCH v6 0/7] MdeModulePkg: add support for dispatching foreign
> arch PE/COFF images
> 
> Add the basic plumbing to DXE core, the PCI bus driver and the boot manager
> to allow PE/COFF images to be dispatched that target an architecture that is
> not native for the platform, but which is supported by one of potentially
> several available emulators.
> 
> One implementation of such an emulator can be found here:
> https://github.com/ardbiesheuvel/X86EmulatorPkg/tree/upstream-v4
> 
> This also allows us to get rid of the special treatment of EBC images in
> core code. Instead, the EbcDxe driver is augmented with an implementation
> of the EDK2 PE/COFF image emulator protocol so that internal knowledge of
> how EBC is implemented (I-cache flushing, thunks) is removed from the DXE
> core.
> 
> Changes since v5:
> - Fix build issues reported by Mike Kinney (#2, #5)
> - Fix CheckPatch.py issue regarding the use of EFI_D_ERROR (#2) [This is code
>   that is only being moved around but I fixed it nonetheless]
> - Use InstallMultipleProtocolInterfaces() to install the EBC protocol and the
>   PE/COFF emu protocol at the same time (to simplify/fix the error path) (#5)
> - Add Mike's Reviewed-by

The series looks good to be.
Please help to address the format issues as I replied in 1/7 and 2/7
patches.

With those addressed, for the series,
Reviewed-by: Hao Wu <hao.a.wu@intel.com>


Best Regards,
Hao Wu

> 
> Changes since v4:
> - Fix an issue in the protocol notify handler pointed out by Mike Kinney (#2)
> 
> Changes since v3:
> - Simplify the handling of option ROMs and Driver#### images, by simply
>   deferring to the LoadImage() boot service to decide whether an image
>   can be supported or not - this removes some redundant checks from the
>   BDS layer and the PCI bus driver.
> - Move the machine type supported by the emulator into the protocol struct,
>   so we can optimize away calls into the emulator for each image loaded.
>   Instead, the LoadImage() code will only invoke the IsSupported() method for
>   images that are known to have a matching machine type.
> 
> Note that I have considered, but ultimately dismissed the suggestion to
> register and unregister emulators via a new protocol. The main issue is
> that registering and unregistering structs containing sets of function
> pointers is awfully similar to managing a protocol database, and we already
> have the code to do that in EDK2.
> 
> So instead, I have removed all the code that iterates over a handle buffer
> of emu protocols and invokes each one to see if it will support the image.
> Instead, this is all done by CoreLoadImage().
> 
> Changes since v2:
> - incorporate feedback from Andrew Fish (delivered in person):
>   * pass a device path into the IsImageSupported() protocol method so that an
>     implementation can blacklist or whitelist certain devices, or implement
>     other policies that depend on the device where the driver originated
>   * allow the emulator to supersede the native loading of the image - this
>     permits things like X86 on X86 emulators for security sandboxing or debug
> 
> Changes since v1:
> - subsume the EBC handling into the EDK2 emulator protocol and abstract
>   away from EBC specifics in core code.
> - allow multiple emulator implementations to co-exist
> - incorporate Star's review feedback
> 
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Andrew Fish <afish@apple.com>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Jaben Carsey <jaben.carsey@intel.com>
> Cc: Steven Shi <steven.shi@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao Wu <hao.a.wu@intel.com>
> 
> Ard Biesheuvel (7):
>   MdeModulePkg: introduce PE/COFF image emulator protocol
>   MdeModulePkg/DxeCore: invoke the emulator protocol for foreign images
>   MdeModulePkg/PciBusDxe: dispatch option ROMs for foreign architectures
>   MdeModulePkg/UefiBootManagerLib: allow foreign Driver#### images
>   MdeModulePkg/EbcDxe: implement the PE/COFF emulator protocol
>   MdePkg/UefiBaseType.h: treat EBC as a non-native machine type
>   MdeModulePkg/DxeCore: remove explicit EBC handling
> 
>  .../Bus/Pci/PciBusDxe/PciOptionRomSupport.c   |   7 -
>  MdeModulePkg/Core/Dxe/DxeMain.h               |   6 +-
>  MdeModulePkg/Core/Dxe/DxeMain.inf             |   2 +-
>  MdeModulePkg/Core/Dxe/Image/Image.c           | 210 +++++++++++++-----
>  .../Include/Protocol/PeCoffImageEmulator.h    | 107 +++++++++
>  .../Library/UefiBootManagerLib/BmLoadOption.c |   6 +-
>  MdeModulePkg/MdeModulePkg.dec                 |   4 +
>  MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf |   3 +
>  MdeModulePkg/Universal/EbcDxe/EbcDxe.inf      |   3 +
>  MdeModulePkg/Universal/EbcDxe/EbcInt.c        | 121 +++++++++-
>  MdeModulePkg/Universal/EbcDxe/EbcInt.h        |   3 +
>  MdePkg/Include/Uefi/UefiBaseType.h            |   6 +-
>  12 files changed, 402 insertions(+), 76 deletions(-)
>  create mode 100644
> MdeModulePkg/Include/Protocol/PeCoffImageEmulator.h
> 
> --
> 2.17.1