Microsoft shows how to mitigate Spectre variant 2 with Retpoline on Windows

Spectre variant

Although it has been more than a year since Spectre found, this vulnerability still plagues many users. Many software and hardware companies, including Intel, Microsoft, and Canonical, issued some method to fix Spectre vulnerabilities but these methods make the performance to lose. To alleviate the performance degradation experienced by AMD and Intel’s older processors, Google developed a new mitigation technology called Retpoline.

Spectre variant

Retpoline technology has been deployed by default in the preview version of the Windows 10 19H1 branch. Earlier this month, Microsoft also released the KB4482887 cumulative update for Windows 10 October update, introducing “Retpoline” and planning to roll it out to more devices. On the official blog post updates, Microsoft guides how consumers can make manual changes in the registry if they want to enable Retpoline on their device.

On Client SKUs:

  1. reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0x400
  2. reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 0x400
  3. Reboot

On Server SKUs:

  1. reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0x400
  2. reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 0x401
  3. Reboot