Are patches needed for the Meltdown and Spectre issues? When I run Microsoft's Get-SpeculationControlSettings PowerShell script from Windows 10 VM under Windows 8.1 x64 host on i5 4670, the output is as follows, indicating the Windows update doesn't seem to work in the VM. OTOH, in the host OS, the first CVE is enabled (has hardware support), and the second CVE test runs without throwing an exception, but the mitigation isn't enabled due to lack of hardware support.
PS C> Get-SpeculationControlSettings
Speculation control settings for CVE-2017-5715 [branch target injection]
Hardware support for branch target injection mitigation is present: False
Windows OS support for branch target injection mitigation is present: True
Windows OS support for branch target injection mitigation is enabled: False
Windows OS support for branch target injection mitigation is disabled by system policy: False
Windows OS support for branch target injection mitigation is disabled by absence of hardware support: True
Speculation control settings for CVE-2017-5754 [rogue data cache load]
Querying kernel VA shadow information failed with error C0000002
At C:\Program Files\WindowsPowerShell\Modules\SpeculationControl\1.0.0\SpeculationControl.psm1:159 char:13
+ throw (("Querying kernel VA shadow information failed wit ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OperationStopped: (Querying kernel... error C000
0002:String) [], RuntimeException
+ FullyQualifiedErrorId : Querying kernel VA shadow information failed wit h error C0000002