Re: [PATCH V2 3/3] UefiCpuPkg: Add New Memory Attributes

["Laszlo Ersek" <lersek@redhat.com>]

On 06/23/20 23:55, Oleksiy Yakovlev wrote:
> Add usage of EFI_MEMORY_SP and EFI_MEMORY_CPU_CRYPTO
> attributes introduced in UEFI 2.8.
> (UEFI 2.8, mantis 1919 and 1872).
> Use attributes bitmasks, defined in MdePkg.
> 
> Signed-off-by: Oleksiy Yakovlev <oleksiyy@ami.com>
> ---
>  UefiCpuPkg/CpuDxe/CpuDxe.c                         | 11 ++++-------
>  UefiCpuPkg/CpuDxe/CpuDxe.h                         | 12 ------------
>  UefiCpuPkg/CpuDxe/CpuPageTable.c                   |  6 +++---
>  UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c |  2 +-
>  4 files changed, 8 insertions(+), 23 deletions(-)
> 
> diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
> index a571fc3..52cc26e 100644
> --- a/UefiCpuPkg/CpuDxe/CpuDxe.c
> +++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
> @@ -10,9 +10,6 @@
>  #include "CpuMp.h"
>  #include "CpuPageTable.h"
>  
> -#define CACHE_ATTRIBUTE_MASK   (EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP)
> -#define MEMORY_ATTRIBUTE_MASK  (EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RO)
> -
>  //
>  // Global Variables
>  //
> @@ -417,8 +414,8 @@ CpuSetMemoryAttributes (
>      return EFI_SUCCESS;
>    }
>  
> -  CacheAttributes = Attributes & CACHE_ATTRIBUTE_MASK;
> -  MemoryAttributes = Attributes & MEMORY_ATTRIBUTE_MASK;
> +  CacheAttributes = Attributes & EFI_CACHE_ATTRIBUTE_MASK;
> +  MemoryAttributes = Attributes & EFI_MEMORY_ATTRIBUTE_MASK;
>  
>    if (Attributes != (CacheAttributes | MemoryAttributes)) {
>      return EFI_INVALID_PARAMETER;

OK.

> @@ -677,7 +674,7 @@ SetGcdMemorySpaceAttributes (
>      gDS->SetMemorySpaceAttributes (
>             RegionStart,
>             RegionLength,
> -           (MemorySpaceMap[Index].Attributes & ~EFI_MEMORY_CACHETYPE_MASK) | (MemorySpaceMap[Index].Capabilities & Attributes)
> +           (MemorySpaceMap[Index].Attributes & ~EFI_CACHE_ATTRIBUTE_MASK) | (MemorySpaceMap[Index].Capabilities & Attributes)
>             );
>    }
>  
> @@ -754,7 +751,7 @@ RefreshMemoryAttributesFromMtrr (
>      gDS->SetMemorySpaceAttributes (
>             MemorySpaceMap[Index].BaseAddress,
>             MemorySpaceMap[Index].Length,
> -           (MemorySpaceMap[Index].Attributes & ~EFI_MEMORY_CACHETYPE_MASK) |
> +           (MemorySpaceMap[Index].Attributes & ~EFI_CACHE_ATTRIBUTE_MASK) |
>             (MemorySpaceMap[Index].Capabilities & DefaultAttributes)
>             );
>    }
> diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.h b/UefiCpuPkg/CpuDxe/CpuDxe.h
> index 9299eaa..9771ec8 100644
> --- a/UefiCpuPkg/CpuDxe/CpuDxe.h
> +++ b/UefiCpuPkg/CpuDxe/CpuDxe.h
> @@ -39,18 +39,6 @@
>  #include <Guid/IdleLoopEvent.h>
>  #include <Guid/VectorHandoffTable.h>
>  
> -#define EFI_MEMORY_CACHETYPE_MASK     (EFI_MEMORY_UC  | \
> -                                       EFI_MEMORY_WC  | \
> -                                       EFI_MEMORY_WT  | \
> -                                       EFI_MEMORY_WB  | \
> -                                       EFI_MEMORY_UCE   \
> -                                       )
> -
> -#define EFI_MEMORY_PAGETYPE_MASK      (EFI_MEMORY_RP  | \
> -                                       EFI_MEMORY_XP  | \
> -                                       EFI_MEMORY_RO    \
> -                                       )
> -
>  #define HEAP_GUARD_NONSTOP_MODE       \
>          ((PcdGet8 (PcdHeapGuardPropertyMask) & (BIT6|BIT4|BIT1|BIT0)) > BIT6)
>  

(1) These changes have an additional effect. EFI_MEMORY_CACHETYPE_MASK
does not include EFI_MEMORY_WP, but EFI_CACHE_ATTRIBUTE_MASK does.

(1a) If that change is intentional, then this patch can remain as it is,
but we need an extra patch prepended (i.e., inserted between v2 patches
#2 and #3), for adding EFI_MEMORY_WP to EFI_MEMORY_CACHETYPE_MASK first.

(1b) If the EFI_MEMORY_WP change is not intended (i.e., it is an
oversight in this patch), then in every spot where we replace
EFI_MEMORY_CACHETYPE_MASK with EFI_CACHE_ATTRIBUTE_MASK, we need to
account for EFI_MEMORY_WP separately.

... After reading up on EFI_MEMORY_WP in the UEFI spec, I think it's
(1a) -- meaning that, this patch is correct, in itself. But, we should
still not hide the EFI_MEMORY_WP bugfix, for EFI_MEMORY_CACHETYPE_MASK,
in this patch.

So please insert a new patch just before this one, that does nothing
other than include EFI_MEMORY_WP in EFI_MEMORY_CACHETYPE_MASK.

The rest of the patch looks OK to me. Therefore, for this patch (in itself):

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Eric, Ray, Rahul: correct me if I'm wrong, please.

Thanks,
Laszlo

> diff --git a/UefiCpuPkg/CpuDxe/CpuPageTable.c b/UefiCpuPkg/CpuDxe/CpuPageTable.c
> index 0a02cb3..06ee1b8 100644
> --- a/UefiCpuPkg/CpuDxe/CpuPageTable.c
> +++ b/UefiCpuPkg/CpuDxe/CpuPageTable.c
> @@ -717,7 +717,7 @@ ConvertMemoryPageAttributes (
>      return RETURN_INVALID_PARAMETER;
>    }
>  
> -  if ((Attributes & ~(EFI_MEMORY_RP | EFI_MEMORY_RO | EFI_MEMORY_XP)) != 0) {
> +  if ((Attributes & ~EFI_MEMORY_ATTRIBUTE_MASK) != 0) {
>      DEBUG ((DEBUG_ERROR, "Attributes(0x%lx) has unsupported bit\n", Attributes));
>      return EFI_UNSUPPORTED;
>    }
> @@ -1018,9 +1018,9 @@ RefreshGcdMemoryAttributesFromPaging (
>  
>        Length = MIN (PageLength, MemorySpaceLength);
>        if (Attributes != (MemorySpaceMap[Index].Attributes &
> -                         EFI_MEMORY_PAGETYPE_MASK)) {
> +                         EFI_MEMORY_ATTRIBUTE_MASK)) {
>          NewAttributes = (MemorySpaceMap[Index].Attributes &
> -                         ~EFI_MEMORY_PAGETYPE_MASK) | Attributes;
> +                         ~EFI_MEMORY_ATTRIBUTE_MASK) | Attributes;
>          Status = gDS->SetMemorySpaceAttributes (
>                          BaseAddress,
>                          Length,
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
> index 9c5a92a..ebfc46a 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
> @@ -435,7 +435,7 @@ ConvertMemoryPageAttributes (
>    EFI_PHYSICAL_ADDRESS              MaximumSupportMemAddress;
>  
>    ASSERT (Attributes != 0);
> -  ASSERT ((Attributes & ~(EFI_MEMORY_RP | EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0);
> +  ASSERT ((Attributes & ~EFI_MEMORY_ATTRIBUTE_MASK) == 0);
>  
>    ASSERT ((BaseAddress & (SIZE_4KB - 1)) == 0);
>    ASSERT ((Length & (SIZE_4KB - 1)) == 0);
>