哪些版本的 Windows 使用 PCID 功能来加速 Meltdown 补丁？

Question

我有Windows 7 企业版 SP1 64 位使用 Intel i7-6820HQ（带有最新微码修订版 0xC6）并且 InSpectre #8 显示我拥有两种保护，但速度较慢。

是不是因为 Windows 7 不使用 PCID 功能？哪些版本使用该功能？

图片：

PS C:\> Get-SpeculationControlSettings
Speculation control settings for CVE-2017-5715 [branch target injection]
For more information about the output below, please refer to https://support.microsoft.com/en-in/help/4074629

Hardware support for branch target injection mitigation is present: True
Windows OS support for branch target injection mitigation is present: True
Windows OS support for branch target injection mitigation is enabled: True

Speculation control settings for CVE-2017-5754 [rogue data cache load]

Hardware requires kernel VA shadowing: True
Windows OS support for kernel VA shadow is present: True
Windows OS support for kernel VA shadow is enabled: True
Windows OS support for PCID performance optimization is enabled: False [not required for security]

Speculation control settings for CVE-2018-3639 [speculative store bypass]

Hardware is vulnerable to speculative store bypass: True
Hardware support for speculative store bypass mitigation is present: True
Windows OS support for speculative store bypass mitigation is present: True
Windows OS support for speculative store bypass mitigation is enabled system-wide: False


BTIHardwarePresent                  : True
BTIWindowsSupportPresent            : True
BTIWindowsSupportEnabled            : True
BTIDisabledBySystemPolicy           : False
BTIDisabledByNoHardwareSupport      : False
KVAShadowRequired                   : True
KVAShadowWindowsSupportPresent      : True
KVAShadowWindowsSupportEnabled      : True
KVAShadowPcidEnabled                : False
SSBDWindowsSupportPresent           : True
SSBDHardwareVulnerable              : True
SSBDHardwarePresent                 : True
SSBDWindowsSupportEnabledSystemWide : False

PS：Coreinfo v3.31 确认硬件支持：

PCID            *       Supports PCIDs and settable CR4.PCIDE
INVPCID         *       Supports INVPCID instruction