On 21/05/20 08:44, Tao Xu wrote: > > I am sorry, I mean: > By default, we don't expose WAITPKG to guest. For QEMU, we can use > "-overcommit cpu-pm=on" to use WAITPKG. But UMONITOR, UMWAIT and TPAUSE are not NOPs on older processors (which I should have checked before committing your patch, I admit). So you have broken "-cpu host -overcommit cpu-pm=on" on any processor that doesn't have WAITPKG. I'll send a patch. Paolo
