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[CHERRY-PICK] UefiCpuPkg/MpInitLib: Enable execute disable bit. #790

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merged 1 commit into from
Apr 5, 2024
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[CHERRY-PICK] UefiCpuPkg/MpInitLib: Enable execute disable bit. #790

merged 1 commit into from
Apr 5, 2024

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kenlautner
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@kenlautner kenlautner commented Apr 5, 2024 •
edited by makubacki
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Description

This patch synchronizes the No-Execute bit in the IA32_EFER register for the APs before the RestoreVolatileRegisters operation.

The commit 964a4f0, titled "Eliminate the second INIT-SIPI-SIPI sequence," replaces the second INIT-SIPI-SIPI sequence with the BSP calling the SwitchApContext function to initiate a specialized start-up signal, waking up APs in the DXE instead of using INIT-SIPI-SIPI.

Due to this change, the logic for "Enable execute disable bit" in MpFuncs.nasm is no longer executed. However, to ensure the proper setup of the page table, it is necessary to synchronize the IA32_EFER.NXE for APs before executing RestoreVolatileRegisters.

Based on SDM:
If IA32_EFER.NXE is set to 1, it signifies execute-disable, meaning instruction fetches are not allowed from the 4-KByte page controlled by this entry. Conversely, if it is set to 0, it is reserved.

Reviewed-by: Laszlo Ersek [email protected]
Reviewed-by: Ray Ni [email protected]
Cc: Laszlo Ersek [email protected]
Cc: Eric Dong [email protected]
Cc: Ray Ni [email protected]
Cc: Rahul Kumar [email protected]
Cc: Gerd Hoffmann [email protected]
(cherry picked from commit cb3f41a)

  • Impacts functionality?
    • Functionality - Does the change ultimately impact how firmware functions?
    • Examples: Add a new library, publish a new PPI, update an algorithm, ...
  • Impacts security?
    • Security - Does the change have a direct security impact on an application,
      flow, or firmware?
    • Examples: Crypto algorithm change, buffer overflow fix, parameter
      validation improvement, ...
  • Breaking change?
    • Breaking change - Will anyone consuming this change experience a break
      in build or boot behavior?
    • Examples: Add a new library class, move a module to a different repo, call
      a function in a new library class in a pre-existing module, ...
  • Includes tests?
    • Tests - Does the change include any explicit test code?
    • Examples: Unit tests, integration tests, robot tests, ...
  • Includes documentation?
    • Documentation - Does the change contain explicit documentation additions
      outside direct code modifications (and comments)?
    • Examples: Update readme file, add feature readme file, link to documentation
      on an a separate Web page, ...

@xieyuanh @kenlautner
UefiCpuPkg/MpInitLib: Enable execute disable bit.
61d54b6 
This patch synchronizes the No-Execute bit in the IA32_EFER
register for the APs before the RestoreVolatileRegisters operation.

The commit 964a4f0, titled "Eliminate the second INIT-SIPI-SIPI
sequence," replaces the second INIT-SIPI-SIPI sequence with the BSP
calling the SwitchApContext function to initiate a specialized start-up
signal, waking up APs in the DXE instead of using INIT-SIPI-SIPI.

Due to this change, the logic for "Enable execute disable bit" in
MpFuncs.nasm is no longer executed. However, to ensure the proper setup
of the page table, it is necessary to synchronize the IA32_EFER.NXE for
APs before executing RestoreVolatileRegisters .

Based on SDM:
If IA32_EFER.NXE is set to 1, it signifies execute-disable, meaning
instruction fetches are not allowed from the 4-KByte page controlled by
this entry. Conversely, if it is set to 0, it is reserved.

Signed-off-by: Yuanhao Xie <[email protected]>
Reviewed-by: Laszlo Ersek <[email protected]>
Reviewed-by: Ray Ni <[email protected]>
Cc: Laszlo Ersek [email protected]
Cc: Eric Dong <[email protected]>
Cc: Ray Ni <[email protected]>
Cc: Rahul Kumar <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
@github-actions github-actions bot added the impact:non-functional Does not have a functional impact label Apr 5, 2024
@makubacki makubacki added the type:bug Something isn't working label Apr 5, 2024
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Note: Updated PR description to include cherry picked commit hash.

@makubacki makubacki removed the impact:non-functional Does not have a functional impact label Apr 5, 2024
@makubacki makubacki requested a review from kuqin12 April 5, 2024 16:40
@makubacki makubacki merged commit 7f1f52f into microsoft:release/202311 Apr 5, 2024
36 checks passed
ProjectMuBot referenced this pull request in microsoft/mu_tiano_platforms Apr 9, 2024
@ProjectMuBot
Bumps MU_BASECORE from 2023110003.1.1 to 2023110003.1.2
575a25e 
Introduces 3 new commits in [MU_BASECORE](https://github.com/microsoft/mu_basecore.git).

<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/microsoft/mu_basecore/commit/ad728a5b0ff40edd2598b2b8b4aa8e35a99ef349">ad728a</a> Updated LinuxCFLAGS to match the change made from edk2 (<a href="https://github.com/microsoft/mu_basecore/pull/789">#789</a>)</li>
<li><a href="https://github.com/microsoft/mu_basecore/commit/7f1f52fc97152e4a2c333aea732b9c644560fd68">7f1f52</a> [CHERRY-PICK] UefiCpuPkg/MpInitLib: Enable execute disable bit. (<a href="https://github.com/microsoft/mu_basecore/pull/790">#790</a>)</li>
<li><a href="https://github.com/microsoft/mu_basecore/commit/822b984a66116b1e4430980175ea497180bad85f">822b98</a> MdeModulePkg/MemoryProtectionSupport: Fix GCC type mismatch warnings (<a href="https://github.com/microsoft/mu_basecore/pull/791">#791</a>)</li>
</ul>
</details>

Signed-off-by: Project Mu Bot <[email protected]>
@ProjectMuBot ProjectMuBot mentioned this pull request Apr 9, 2024
Merged
kuqin12 referenced this pull request in microsoft/mu_tiano_platforms Apr 9, 2024
@ProjectMuBot
Bump MU_BASECORE from 2023110003.1.1 to 2023110003.1.2 (#903)
c44a559 
Bumps MU_BASECORE from `2023110003.1.1` to `2023110003.1.2`

Introduces 3 new commits in
[MU_BASECORE](https://github.com/microsoft/mu_basecore.git).

<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/microsoft/mu_basecore/commit/ad728a5b0ff40edd2598b2b8b4aa8e35a99ef349">ad728a</a>
Updated LinuxCFLAGS to match the change made from edk2 (<a
href="https://github.com/microsoft/mu_basecore/pull/789">#789</a>)</li>
<li><a
href="https://github.com/microsoft/mu_basecore/commit/7f1f52fc97152e4a2c333aea732b9c644560fd68">7f1f52</a>
[CHERRY-PICK] UefiCpuPkg/MpInitLib: Enable execute disable bit. (<a
href="https://github.com/microsoft/mu_basecore/pull/790">#790</a>)</li>
<li><a
href="https://github.com/microsoft/mu_basecore/commit/822b984a66116b1e4430980175ea497180bad85f">822b98</a>
MdeModulePkg/MemoryProtectionSupport: Fix GCC type mismatch warnings (<a
href="https://github.com/microsoft/mu_basecore/pull/791">#791</a>)</li>
</ul>
</details>

Signed-off-by: Project Mu Bot <[email protected]>
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@kuqin12 kuqin12 kuqin12 approved these changes

@makubacki makubacki makubacki approved these changes

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@kenlautner @makubacki @kuqin12 @xieyuanh