On Sat, Jan 7, 2023 at 11:04 AM Dave Voutila <d...@sisu.io> wrote: > Bringing this to tech@ to increase my chance of someone testing my > diff. > > As reported in this thread on misc@ [1], I believe newer Intel hardware > may be experiencing issues hosting Linux guests under vmm/vmd. It looks > like there are some newer instructions Intel added (TPAUSE specifically) > that also involve some new MSR(s). > > I don't have 12th gen Intel hardware to test this on (I think that's > Alder Lake). I'd like to mask this feature from vmm guests since it's > related to an MSR we don't yet pass through or emulate and has to do > with the TSC (which has it's own challenges in vmm). > > For someone testing, you should be able to grab an Alpine Linux iso > (-virt flavor) and boot it with vmd with the diff. (Without it should > "hang" and spike CPU or just die.) Also check that WAITPKG shows up in > your dmesg on the cpu feature output. >
This seem like it'll obviously work, but I guess it seems to me that this "opt-out" approach is generally unsafe/unstable and vmd should consider actively switching to "opt-in" on all these CPUID feature bits. I mean, what bits are defined in the SEFF first-leaf EDX that _do_ work with vmd? Philip
