Re: [RFC] [PATCH V4 0/3] Add IOMMU support.

["Yao, Jiewen" <jiewen.yao@intel.com>]

Thanks. I agree.

From: Ni, Ruiyu
Sent: Thursday, May 4, 2017 3:02 PM
To: Yao, Jiewen <jiewen.yao@intel.com>; edk2-devel@lists.01.org
Cc: Leo Duran <leo.duran@amd.com>; Brijesh Singh <brijesh.singh@amd.com>; Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: RE: [RFC] [PATCH V4 0/3] Add IOMMU support.

Jiewen,
All 3 patches are good to me.
When you post V5 to retire one of the SetxxxAttribute() interfaces from IO_MMU protocol,
I suggest we keep the Mapping version, but rename the function name to SetAttribute().
As the 2 changes in below:

typedef
EFI_STATUS
(EFIAPI *EDKII_IOMMU_SET_ATTRIBUTE)( // <-- 1. Remove the _MAPPING
  IN EDKII_IOMMU_PROTOCOL  *This,
  IN EFI_HANDLE            DeviceHandle,
  IN VOID                  *Mapping,
  IN UINT64                IoMmuAccess
  );

///
/// IOMMU Protocol structure.
///
struct _EDKII_IOMMU_PROTOCOL {
  UINT64                              Revision;
  EDKII_IOMMU_SET_ATTRIBUTE           SetAttribute;
  EDKII_IOMMU_MAP                     Map;
  EDKII_IOMMU_UNMAP                   Unmap;
  EDKII_IOMMU_ALLOCATE_BUFFER         AllocateBuffer;
  EDKII_IOMMU_FREE_BUFFER             FreeBuffer;
  // <-- 2. Remove the SetMappingAttribute interface.
};

Thanks/Ray

> -----Original Message-----
> From: Yao, Jiewen
> Sent: Saturday, April 29, 2017 9:48 PM
> To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>; Leo Duran <leo.duran@amd.com<mailto:leo.duran@amd.com>>; Brijesh
> Singh <brijesh.singh@amd.com<mailto:brijesh.singh@amd.com>>; Ard Biesheuvel <ard.biesheuvel@linaro.org<mailto:ard.biesheuvel@linaro.org>>
> Subject: [RFC] [PATCH V4 0/3] Add IOMMU support.
>
> ================ V4 ==============
> Refine the EDKII_IOMMU_PROTOCOL.
>
> 1) Add AllocateBuffer/FreeBuffer/Map/Unmap() API.
> They are similar to DmaLib in EmbeddedPkg and similar to the previous
> BmDmaLib (by leo.duran@amd.com<mailto:leo.duran@amd.com>).
>
> These APIs are invoked by PciHostBridge driver to allocate DMA memory.
>
> The PciHostBridge driver (IOMMU consumer) is simplified:
> It uses IOMMU, if IOMMU protocol is present.
> Else it uses original logic.
>
> 2) Add SetMappingAttribute() API.
> It is similar to SetAttribute() API in V1.
>
> This API is invoked by PciBus driver to set DMA access attribute (read/write) for
> device.
>
> The PciBus driver (IOMMU consumer) is simplified:
> It sets access attribute in Map/Unmap,
> if IOMMU protocol is present.
>
> 3) Remove SetRemapAddress/GetRemapAddress() API.
> Because PciHostBridge/PciBus can call the APIs defined above, there is no need
> to provide remap capability.
>
> -- Sample producer drivers:
> 1) The sample VTd driver (IOMMU producer) is at
> https://github.com/jyao1/edk2/tree/dma_v4/IntelSiliconPkg/IntelVTdDxe
>
> It is added to show the concept. It is not fully implemented yet.
> It will not be checked in in this patch.
>
> 2) The sample AMD SEV driver (IOMMU producer) is at
> https://github.com/jyao1/edk2/tree/dma_v4/IntelSiliconPkg/SampleAmdSevDx
> e
> (code is borrowed from leo.duran@amd.com<mailto:leo.duran@amd.com> and brijesh.singh@amd.com<mailto:brijesh.singh@amd.com>)
>
> This is not a right place to put this driver.
>
> It is added to show the concept.
> It is not fully implemented. It will not be checked in.
> Please do not use it directly.
>
> 3) The sample STYX driver (IOMMU producer) is at
> https://github.com/jyao1/edk2/tree/dma_v4/IntelSiliconPkg/SampleStyxDxe
> (code is borrowed from ard.biesheuvel@linaro.org<mailto:ard.biesheuvel@linaro.org>)
>
> This is not a right place to put this driver.
>
> It is added to show the concept.
> It is not fully implemented. It will not be checked in.
> Please do not use it directly.
>
>
> ================ V3 ==============
> 1) Add Remap capability (from Ard Biesheuvel) Add
> EDKII_IOMMU_REMAP_ADDRESS API in IOMMU_PROTOCOL.
>
> NOTE: The code is not fully validated yet.
> The purpose is to collect feedback to decide the next step.
>
> ================ V2 ==============
> 1) Enhance Unmap() in PciIo (From Ruiyu Ni) Maintain a local list of MapInfo and
> match it in Unmap.
>
> 2) CopyMem for ReadOperation in PciIo after SetAttribute (Leo Duran) Fix a bug
> in V1 that copy mem for read happen before SetAttribute, which will break AMD
> SEV solution.
>
> ================ V1 ==============
>
> This patch series adds IOMMU protocol and updates the consumer to support
> IOMMU based DMA access in UEFI.
>
> This patch series can support the BmDmaLib request for AMD SEV.
> submitted by Duran, Leo <leo.duran@amd.com<mailto:leo.duran@amd.com>> and Brijesh Singh
> <brijesh.ksingh@gmail.com<mailto:brijesh.ksingh@gmail.com>>.
> https://lists.01.org/pipermail/edk2-devel/2017-March/008109.html, and
> https://lists.01.org/pipermail/edk2-devel/2017-March/008820.html.
> We can have an AMD SEV specific IOMMU driver to produce IOMMU protocol,
> and clear SEV in IOMMU->SetAttribute().
>
> This patch series can also support Intel VTd based DMA protection, requested by
> Jiewen Yao <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>, discussed in
> https://lists.01.org/pipermail/edk2-devel/2017-March/008157.html.
> We can have an Intel VTd specific IOMMU driver to produce IOMMU protocol,
> and update VTd engine to grant or deny access in IOMMU->SetAttribute().
>
> This patch series does not provide a full Intel VTd driver, which will be provide in
> other patch in the future.
>
> The purpose of this patch series to review if this IOMMU protocol design can
> meet all DMA access and management requirement.
>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>
> Cc: Leo Duran <leo.duran@amd.com<mailto:leo.duran@amd.com>>
> Cc: Brijesh Singh <brijesh.singh@amd.com<mailto:brijesh.singh@amd.com>>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org<mailto:ard.biesheuvel@linaro.org>>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jiewen Yao <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>
>
> Jiewen Yao (3):
>   MdeModulePkg/Include: Add IOMMU protocol definition.
>   MdeModulePkg/PciHostBridge: Add IOMMU support.
>   MdeModulePkg/PciBus: Add IOMMU support.
>
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c                    |   9 +
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h                    |   1 +
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf               |   1 +
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c                     |  37 +++
>  MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c      |  37 +++
>  MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf |   2 +
>  MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h      |   2 +
>  MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c    |  61 ++++
>  MdeModulePkg/Include/Protocol/IoMmu.h                      | 310
> ++++++++++++++++++++
>  MdeModulePkg/MdeModulePkg.dec                              |   3 +
>  10 files changed, 463 insertions(+)
>  create mode 100644 MdeModulePkg/Include/Protocol/IoMmu.h
>
> --
> 2.7.4.windows.1