On Thu, Sep 30, 2021, Oliver Upton wrote: > On Thu, Sep 30, 2021 at 10:09 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > Unlike PSCI power-off, WFI isn't cross-vCPU, thus there's no hard requirement > > for using a request. And KVM_REQ_SLEEP also has an additional guard in that it > > doesn't enter rcuwait if power_off (or pause) was cleared after the request was > > made, e.g. if userspace stuffed vCPU state and set the vCPU RUNNABLE. > > Yeah, I don't think the punt is necessary for anything but the case > where userspace sets the MP state to request WFI behavior. A helper > method amongst all WFI cases is sufficient, and using the deferral for > everything is a change in behavior. Is there an actual use case for letting userspace request WFI behavior?
