Stefan Hajnoczi writes: > On Wed, Sep 14, 2016 at 06:01:17PM +0200, Lluís Vilanova wrote: >> Stefan Hajnoczi writes: >> >> > On Tue, Sep 06, 2016 at 04:25:53PM +0200, Lluís Vilanova wrote: >> >> +## vCPU >> >> + >> >> +# Create a new virtual (guest) CPU >> >> +# >> >> +# Targets: all >> >> +guest_cpu_init(void *cpu) "cpu=%p" >> >> > This isn't a vcpu trace event. Please add keep it with the other >> > non-vcpu trace events: >> >> > # cpus.c >> > guest_cpu_init(void *cpu) "cpu=%p" >> >> It actually is, but as the commit message says, declaring it as such prevents >> the event to be emitted.
> If it cannot be toggled on a per-vcpu basis then claiming it's a vcpu > event doesn't make sense. >> The culprit of this problem is that new vCPUs start with an empty per-vCPU >> trace >> event set. Should we make vCPUs "inherit" the state from the global state? >> (i.e., if any vcpu event is set on any vCPU, set it on the new one). The next >> question would then be, should this inheritance only apply until tracing is >> fully initialized of for the whole duration of QEMU? > I think the underlying issue is that trace_init_vcpu_events() assumes > there is a single instant where vcpus all exist and need to be > initialized. > A model that supports vcpu hotplug is really needed. In that model the > global dstate should be the "global" state that determines whether vcpus > are initialized with the event enabled or disabled. Ok, so then you're going for what I was saying. "Inheriting" the state of every new vCPU from the global dynamic state. If *any* vCPU has an event enabled, all new vCPUs will too. As I said, next question is whether inheritance should apply only until full initialization, or the whole time. I thing the latter is less confusing. Cheers, Lluis
