Re: [edk2-devel] [PATCH v3 13/39] UefiCpuPkg: Add CpuMmuLib.h to UefiCpuPkg

["Chao Li" <lichao@loongson.cn>]

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Hi Ray,

Thanks for review, here are some of my thoughts:


Thanks,
Chao
On 2023/11/30 08:59, Ni, Ray wrote:
> Chao,
> Since the lib class is so general, I'd like to understand more details to make sure it can properly fit into any CPU arch.
>
> In X86, cache setting is through MSRs and Page tables, and memory access control (read-only, not-present, non-executable) is through page tables.
Let me understand, 'cache setting' means does it access a certain 
address(probably a memory address) via cache? If so, I'd say the 'cache 
setting' should be a part of attributes.
>
> This CpuMmuLib is to provide both services. How does LoongArch64 manage the cache settings and memory access control?
> Is it proper to combine both services into one lib?
In LoongArch64, cache settings and memory access control are performed 
via page tables. Please check the patch 14 of this series.
>
> If the backend silicon IP is the same one that supports the "one" lib design, can we refine the lib API a bit?
Yes, I think Attribute's instance family can be bear the memory access 
and cache setting. So what are you suggestions if we improve the lib API?
>
> We have (Set|Get)MemoryRegionAttribute() and (Set|Clear)MemoryRegion(NoExec|ReadOnly). Can we merge them together?
Do you means the (Set|Get) merge together(differentiate Get or Set 
operations by parameters)? If so, I think it's OK, but maybe some 
existing instances will be modified together.
>
> And the API ConfigureMemoryManagementUint() accepts MEMORY_REGION_DESCRIPTOR but none of other APIs helps to construct the descriptor.
Yes, currently, no one helps construct MEMORY_REGION_DESCRIPTOR. I think 
the construction of descriptors is not part of the API, it should be the 
localized or private when I design them. Do I need to add an API to 
construct descripters?
>
> It seems to me the MmuLib is simply a combination of different random APIs.
> It's not a well-designed library class.
>
> We need more discussion to make it be able to be accommodated by other archs in future, at least by figuring out the path of X86, ARM.
Yes, the APIs looks like so fragmented and we should improve them. So we 
should talk more about this API, thanks.
>
> Thanks,
> Ray
>> -----Original Message-----
>> From: Chao Li<lichao@loongson.cn>
>> Sent: Friday, November 17, 2023 6:00 PM
>> To:devel@edk2.groups.io
>> Cc: Dong, Eric<eric.dong@intel.com>; Ni, Ray<ray.ni@intel.com>; Kumar,
>> Rahul R<rahul.r.kumar@intel.com>; Gerd Hoffmann<kraxel@redhat.com>;
>> Leif Lindholm<quic_llindhol@quicinc.com>; Ard Biesheuvel
>> <ardb+tianocore@kernel.org>; Sami Mujawar<sami.mujawar@arm.com>;
>> Sunil V L<sunilvl@ventanamicro.com>; Warkentin, Andrei
>> <andrei.warkentin@intel.com>
>> Subject: [PATCH v3 13/39] UefiCpuPkg: Add CpuMmuLib.h to UefiCpuPkg
>>
>> Add a new header file CpuMmuLib.h, whitch is referenced from
>> ArmPkg/Include/Library/ArmMmuLib.h. Currently, only support for
>> LoongArch64 is added, and more architectures can be accommodated in the
>> future.
>>
>> BZ:https://bugzilla.tianocore.org/show_bug.cgi?id=4584
>>
>> Cc: Eric Dong<eric.dong@intel.com>
>> Cc: Ray Ni<ray.ni@intel.com>
>> Cc: Rahul Kumar<rahul1.kumar@intel.com>
>> Cc: Gerd Hoffmann<kraxel@redhat.com>
>> Cc: Leif Lindholm<quic_llindhol@quicinc.com>
>> Cc: Ard Biesheuvel<ardb+tianocore@kernel.org>
>> Cc: Sami Mujawar<sami.mujawar@arm.com>
>> Cc: Sunil V L<sunilvl@ventanamicro.com>
>> Cc: Andrei Warkentin<andrei.warkentin@intel.com>
>> Signed-off-by: Chao Li<lichao@loongson.cn>
>> ---
>>   UefiCpuPkg/Include/Library/CpuMmuLib.h | 155
>> +++++++++++++++++++++++++
>>   UefiCpuPkg/UefiCpuPkg.dec              |   4 +
>>   2 files changed, 159 insertions(+)
>>   create mode 100644 UefiCpuPkg/Include/Library/CpuMmuLib.h
>>
>> diff --git a/UefiCpuPkg/Include/Library/CpuMmuLib.h
>> b/UefiCpuPkg/Include/Library/CpuMmuLib.h
>> new file mode 100644
>> index 0000000000..23b2fe34ac
>> --- /dev/null
>> +++ b/UefiCpuPkg/Include/Library/CpuMmuLib.h
>> @@ -0,0 +1,155 @@
>> +/** @file
>> +
>> +  Copyright (c) 2023 Loongson Technology Corporation Limited. All rights
>> reserved.<BR>
>> +
>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +
>> +**/
>> +
>> +#ifndef CPU_MMU_LIB_H_
>> +#define CPU_MMU_LIB_H_
>> +
>> +#include <Uefi/UefiBaseType.h>
>> +
>> +#define EFI_MEMORY_CACHETYPE_MASK  (EFI_MEMORY_UC  | \
>> +                                    EFI_MEMORY_WC  | \
>> +                                    EFI_MEMORY_WT  | \
>> +                                    EFI_MEMORY_WB  | \
>> +                                    EFI_MEMORY_UCE   \
>> +                                    )
>> +
>> +typedef struct {
>> +  EFI_PHYSICAL_ADDRESS    PhysicalBase;
>> +  EFI_VIRTUAL_ADDRESS     VirtualBase;
>> +  UINTN                   Length;
>> +  UINTN                   Attributes;
>> +} MEMORY_REGION_DESCRIPTOR;
>> +
>> +/**
>> +  Converts EFI Attributes to corresponding architecture Attributes.
>> +
>> +  @param[in]  EfiAttributes     Efi Attributes.
>> +
>> +  @retval  Corresponding architecture attributes.
>> +**/
>> +UINTN
>> +EfiAttributeConverse (
>> +  IN UINTN  EfiAttributes
>> +  );
>> +
>> +/**
>> +  Finds the length and memory properties of the memory region
>> corresponding to the specified base address.
>> +
>> +  @param[in]  BaseAddress    To find the base address of the memory
>> region.
>> +  @param[in]  EndAddress     To find the end address of the memory
>> region.
>> +  @param[out]  RegionLength    The length of the memory region
>> found.
>> +  @param[out]  RegionAttributes    Properties of the memory region
>> found.
>> +
>> +  @retval  EFI_SUCCESS    The corresponding memory area was
>> successfully found
>> +           EFI_NOT_FOUND    No memory area found
>> +**/
>> +EFI_STATUS
>> +GetMemoryRegionAttribute (
>> +  IN     UINTN  BaseAddress,
>> +  IN     UINTN  EndAddress,
>> +  OUT    UINTN  *RegionLength,
>> +  OUT    UINTN  *RegionAttributes
>> +  );
>> +
>> +/**
>> +  Sets the Attributes  of the specified memory region
>> +
>> +  @param[in]  BaseAddress    The base address of the memory region
>> to set the Attributes.
>> +  @param[in]  Length         The length of the memory region to set
>> the Attributes.
>> +  @param[in]  Attributes     The Attributes to be set.
>> +  @param[in]  AttributeMask  Mask of memory attributes to take into
>> account.
>> +
>> +  @retval  EFI_SUCCESS    The Attributes was set successfully
>> +**/
>> +EFI_STATUS
>> +SetMemoryRegionAttributes (
>> +  IN EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN UINTN                 Length,
>> +  IN UINTN                 Attributes,
>> +  IN UINT64                AttributeMask
>> +  );
>> +
>> +/**
>> +  Sets the non-executable Attributes for the specified memory region
>> +
>> +  @param[in]  BaseAddress  The base address of the memory region to
>> set the Attributes.
>> +  @param[in]  Length       The length of the memory region to set the
>> Attributes.
>> +
>> +  @retval  EFI_SUCCESS    The Attributes was set successfully
>> +**/
>> +EFI_STATUS
>> +SetMemoryRegionNoExec (
>> +  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN  UINTN                 Length
>> +  );
>> +
>> +/**
>> +  Clears the non-executable Attributes for the specified memory region
>> +
>> +  @param[in]  BaseAddress  The base address of the memory region to
>> clear the Attributes.
>> +  @param[in]  Length       The length of the memory region to clear
>> the Attributes.
>> +
>> +  @retval  EFI_SUCCESS    The Attributes was clear successfully
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +ClearMemoryRegionNoExec (
>> +  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN  UINT64                Length
>> +  );
>> +
>> +/**
>> +  Sets the read-only Attributes for the specified memory region
>> +
>> +  @param[in]  BaseAddress  The base address of the memory region to
>> set the Attributes.
>> +  @param[in]  Length       The length of the memory region to set the
>> Attributes.
>> +
>> +  @retval  EFI_SUCCESS    The Attributes was set successfully
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +SetMemoryRegionReadOnly (
>> +  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN  UINT64                Length
>> +  );
>> +
>> +/**
>> +  Clears the read-only Attributes for the specified memory region
>> +
>> +  @param[in]  BaseAddress  The base address of the memory region to
>> clear the Attributes.
>> +  @param[in]  Length       The length of the memory region to clear
>> the Attributes.
>> +
>> +  @retval  EFI_SUCCESS    The Attributes was clear successfully
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +ClearMemoryRegionReadOnly (
>> +  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN  UINT64                Length
>> +  );
>> +
>> +/**
>> +  Create a page table and initialize the memory management unit(MMU).
>> +
>> +  @param[in]  MemoryTable           A pointer to a memory ragion
>> table.
>> +  @param[out] TranslationTableBase  A pointer to a translation table base
>> address.
>> +  @param[out] TranslationTableSize  A pointer to a translation table base
>> size.
>> +
>> +  @retval  EFI_SUCCESS                Configure MMU successfully.
>> +           EFI_INVALID_PARAMETER      MemoryTable is NULL.
>> +           EFI_UNSUPPORTED            Out of memory space or
>> size not aligned.
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +ConfigureMemoryManagementUint (
>> +  IN  MEMORY_REGION_DESCRIPTOR  *MemoryTable,
>> +  OUT VOID                      **TranslationTableBase OPTIONAL,
>> +  OUT UINTN                     *TranslationTableSize  OPTIONAL
>> +  );
>> +
>> +#endif // CPU_MMU_LIB_H_
>> diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
>> index 154b1d06fe..150beae981 100644
>> --- a/UefiCpuPkg/UefiCpuPkg.dec
>> +++ b/UefiCpuPkg/UefiCpuPkg.dec
>> @@ -62,6 +62,10 @@
>>     ##  @libraryclass  Provides function for manipulating x86 paging
>> structures.
>>     CpuPageTableLib|Include/Library/CpuPageTableLib.h
>>
>> +[LibraryClasses.LoongArch64]
>> +  ##  @libraryclass  Provides macros and functions for the memory
>> management unit.
>> +  CpuMmuLib|Include/Library/CpuMmuLib.h
>> +
>>     ## @libraryclass   Provides functions for manipulating smram savestate
>> registers.
>>     MmSaveStateLib|Include/Library/MmSaveStateLib.h
>>
>> --
>> 2.27.0
>
>
> 
>


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