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Enable Spectre and Meltdown mitigations

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The FeatureSettingsOverride registry key in Windows, typically found under SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management and often managed alongside FeatureSettingsOverrideMask, provides administrators with granular control over software-based mitigations for CPU speculative execution vulnerabilities like Spectre and Meltdown. These vulnerabilities can potentially allow unauthorized access to sensitive data. Windows implements various mitigations to counter these threats, but they can sometimes introduce performance overhead. The FeatureSettingsOverride key allows for a tailored approach, enabling administrators to selectively enable or disable specific mitigations—such as those for different variants of Spectre (like v2 or Speculative Store Bypass - SSB) and Meltdown—or even to disable all of them if the performance impact is deemed too high for a particular environment, or to apply specific configurations like disabling Hyper-Threading on Intel CPUs in conjunction with these mitigations.

Policy Details

Policy Name
MicroarchHardening
Registry Key
SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
Supported On
At least Windows Server 2016, Windows 10
Available Languages
en-usfr-fr

Configuration Elements

Select an option:

Type: enum

Allowed Values
  • 72 Intel and AMD: enable all available mitigations
  • 8264 Intel: enable all mitigations (with Hyper-Threading disabled)
  • 8 Intel: enable mitigations for Spectre v2, Meltdown, and SSB
  • 0 Intel: enable mitigations for Spectre v2 and Meltdown
  • 1 Intel: enable mitigations for Meltdown only
  • 64 AMD and ARM: enable mitigations for Spectre v2
  • 3 Disable all mitigations

Enable Hyper-V mitigations for virtual machines below version 8.0

Type: boolean

True:1.0
False:Not set