Comment by pbsd
9 years ago
Windows does have a microcode update driver, as you would expect, so it can fix this.
However, looking at the microcode update driver on an updated Windows 10 as of right now, I don't see a recent enough microcode version to fix it. The latest updates appear to be from 2015.
That's pretty cool, I didn't know of this functionality. Is there a good resource on how to look it up?
I haven't seen a description of it anywhere that I can think of. The driver lives in C:\Windows\system32\mcupdate_{genuineintel,authenticamd}.dll. All it does is detect which CPU it's running on, and load the appropriate microcode.
Loading the microcode is straightforward---all you need to do is put a few values in the appropriate MSRs. This is described in the Intel manuals, Volume 3. The microcode itself is embedded in the above DLLs, as a big binary table. The latest entry I see is 20150812 for the Intel 0x40651, aka Haswell.