> On Jan 31, 2018, at 2:06 PM, Jim Mattson <jmattson@xxxxxxxxxx> wrote: > >> On Wed, Jan 31, 2018 at 1:59 PM, David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote: >> I'm actually working on IBRS_ALL at the moment. >> >> I was tempted to *not* let the guests turn it off. Expose SPEC_CTRL but >> just make it a no-op. > > Maybe we could convince Intel to add a LOCK bit to IA32_SPEC_CTRL like > the one in IA32_FEATURE_CONTROL. Please no. Some BIOS vendor is going to lock it to zero to win some silly benchmark.
