[PATCH 0/2] UefiCpuPkg/PiSmmCpuDxeSmm: drop support for obsolete processors, fix error handling

[PATCH 0/2] UefiCpuPkg/PiSmmCpuDxeSmm: drop support for obsolete processors, fix error handling

[Gerd Hoffmann]

Gerd Hoffmann (2):
  UefiCpuPkg/PiSmmCpuDxeSmm: drop support for obsolete processors
  UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling

 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

-- 
2.39.2

[PATCH 1/2] UefiCpuPkg/PiSmmCpuDxeSmm: drop support for obsolete processors

[Gerd Hoffmann]

It's highly unlikely the code ever runs on processors which are
almost 30 years old.  Drop the code handling them.

Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=4345
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
index d2d0950f3b42..55a9f79da8eb 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
@@ -871,24 +871,14 @@ PiCpuSmmEntry (
     //
     DEBUG ((DEBUG_INFO, "PiCpuSmmEntry: gSmmBaseHobGuid not found!\n"));
     //
+    // very old processors (i486 + pentium) need 32k not 4k alignment, exclude them.
+    //
+    ASSERT (FamilyId >= 6);
+    //
     // Allocate buffer for all of the tiles.
     //
-    // Intel(R) 64 and IA-32 Architectures Software Developer's Manual
-    // Volume 3C, Section 34.11 SMBASE Relocation
-    //   For Pentium and Intel486 processors, the SMBASE values must be
-    //   aligned on a 32-KByte boundary or the processor will enter shutdown
-    //   state during the execution of a RSM instruction.
-    //
-    // Intel486 processors: FamilyId is 4
-    // Pentium processors : FamilyId is 5
-    //
     BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
-    if ((FamilyId == 4) || (FamilyId == 5)) {
-      Buffer = AllocateAlignedCodePages (BufferPages, SIZE_32KB);
-    } else {
-      Buffer = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
-    }
-
+    Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
     ASSERT (Buffer != NULL);
     DEBUG ((DEBUG_INFO, "New Allcoated SMRAM SaveState Buffer (0x%08x, 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE (BufferPages)));
   }
-- 
2.39.2

[PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling

[Gerd Hoffmann]

ASSERT() is not proper handling of allocation failures, it gets compiled
out on RELEASE builds.  Print a message and enter dead loop instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
index 55a9f79da8eb..2e41df1f1074 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
@@ -879,6 +879,12 @@ PiCpuSmmEntry (
     //
     BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
     Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
+    if (!Buffer) {
+      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
+      CpuDeadLoop ();
+      return EFI_OUT_OF_RESOURCES;
+    }
+
     ASSERT (Buffer != NULL);
     DEBUG ((DEBUG_INFO, "New Allcoated SMRAM SaveState Buffer (0x%08x, 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE (BufferPages)));
   }
-- 
2.39.2

Re: [PATCH 1/2] UefiCpuPkg/PiSmmCpuDxeSmm: drop support for obsolete processors

[Ni, Ray]

Reviewed-by: Ray Ni <ray.ni@intel.com>

> -----Original Message-----
> From: Gerd Hoffmann <kraxel@redhat.com>
> Sent: Friday, March 10, 2023 8:49 PM
> To: devel@edk2.groups.io
> Cc: Ni, Ray <ray.ni@intel.com>; Oliver Steffen <osteffen@redhat.com>; Gerd
> Hoffmann <kraxel@redhat.com>; Kumar, Rahul R
> <rahul.r.kumar@intel.com>; Pawel Polawski <ppolawsk@redhat.com>;
> Dong, Eric <eric.dong@intel.com>
> Subject: [PATCH 1/2] UefiCpuPkg/PiSmmCpuDxeSmm: drop support for
> obsolete processors
> 
> It's highly unlikely the code ever runs on processors which are
> almost 30 years old.  Drop the code handling them.
> 
> Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=4345
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 20 +++++---------------
>  1 file changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> index d2d0950f3b42..55a9f79da8eb 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> @@ -871,24 +871,14 @@ PiCpuSmmEntry (
>      //
>      DEBUG ((DEBUG_INFO, "PiCpuSmmEntry: gSmmBaseHobGuid not
> found!\n"));
>      //
> +    // very old processors (i486 + pentium) need 32k not 4k alignment,
> exclude them.
> +    //
> +    ASSERT (FamilyId >= 6);
> +    //
>      // Allocate buffer for all of the tiles.
>      //
> -    // Intel(R) 64 and IA-32 Architectures Software Developer's Manual
> -    // Volume 3C, Section 34.11 SMBASE Relocation
> -    //   For Pentium and Intel486 processors, the SMBASE values must be
> -    //   aligned on a 32-KByte boundary or the processor will enter shutdown
> -    //   state during the execution of a RSM instruction.
> -    //
> -    // Intel486 processors: FamilyId is 4
> -    // Pentium processors : FamilyId is 5
> -    //
>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> (mMaxNumberOfCpus - 1));
> -    if ((FamilyId == 4) || (FamilyId == 5)) {
> -      Buffer = AllocateAlignedCodePages (BufferPages, SIZE_32KB);
> -    } else {
> -      Buffer = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
> -    }
> -
> +    Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
>      ASSERT (Buffer != NULL);
>      DEBUG ((DEBUG_INFO, "New Allcoated SMRAM SaveState Buffer (0x%08x,
> 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE (BufferPages)));
>    }
> --
> 2.39.2

Re: [PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling

[Ni, Ray]

Reviewed-by: Ray Ni <ray.ni@intel.com>

> -----Original Message-----
> From: Gerd Hoffmann <kraxel@redhat.com>
> Sent: Friday, March 10, 2023 8:49 PM
> To: devel@edk2.groups.io
> Cc: Ni, Ray <ray.ni@intel.com>; Oliver Steffen <osteffen@redhat.com>; Gerd
> Hoffmann <kraxel@redhat.com>; Kumar, Rahul R
> <rahul.r.kumar@intel.com>; Pawel Polawski <ppolawsk@redhat.com>;
> Dong, Eric <eric.dong@intel.com>
> Subject: [PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling
> 
> ASSERT() is not proper handling of allocation failures, it gets compiled
> out on RELEASE builds.  Print a message and enter dead loop instead.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> index 55a9f79da8eb..2e41df1f1074 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> @@ -879,6 +879,12 @@ PiCpuSmmEntry (
>      //
>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> (mMaxNumberOfCpus - 1));
>      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
> +    if (!Buffer) {
> +      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> +      CpuDeadLoop ();
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +
>      ASSERT (Buffer != NULL);
>      DEBUG ((DEBUG_INFO, "New Allcoated SMRAM SaveState Buffer (0x%08x,
> 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE (BufferPages)));
>    }
> --
> 2.39.2

Re: [PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling

[Ni, Ray]

Just found "if (!Buffer)" doesn't follow EDK2 coding style.
I changed to "if (Buffer == NULL) {" in final merge PR.

> -----Original Message-----
> From: Gerd Hoffmann <kraxel@redhat.com>
> Sent: Friday, March 10, 2023 8:49 PM
> To: devel@edk2.groups.io
> Cc: Ni, Ray <ray.ni@intel.com>; Oliver Steffen <osteffen@redhat.com>;
> Gerd Hoffmann <kraxel@redhat.com>; Kumar, Rahul R
> <rahul.r.kumar@intel.com>; Pawel Polawski <ppolawsk@redhat.com>; Dong,
> Eric <eric.dong@intel.com>
> Subject: [PATCH 2/2] UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling
> 
> ASSERT() is not proper handling of allocation failures, it gets compiled
> out on RELEASE builds.  Print a message and enter dead loop instead.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> index 55a9f79da8eb..2e41df1f1074 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> @@ -879,6 +879,12 @@ PiCpuSmmEntry (
>      //
>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> (mMaxNumberOfCpus - 1));
>      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
> +    if (!Buffer) {
> +      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> +      CpuDeadLoop ();
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +
>      ASSERT (Buffer != NULL);
>      DEBUG ((DEBUG_INFO, "New Allcoated SMRAM SaveState Buffer (0x%08x,
> 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE (BufferPages)));
>    }
> --
> 2.39.2