On 7 December 2017 at 17:07, Eduardo Habkost <ehabk...@redhat.com> wrote: > On Thu, Dec 07, 2017 at 04:53:59PM +0000, Peter Maydell wrote: >> On 7 December 2017 at 16:48, Igor Mammedov <imamm...@redhat.com> wrote: >> > On Thu, 7 Dec 2017 16:05:50 +0000 >> > Peter Maydell <peter.mayd...@linaro.org> wrote: >> > >> >> Hi; I'm currently writing '-cpu max' support for ARM. For that I'd >> >> like to be able to do the "probe host kernel for its supported feature >> >> set" in the CPU object's instance-init function, but I'd like to do > > I don't think instance_init is appropriate for that, as > object_free(object_new(t)) must be always safe to call and free > of side-effects for all types. Wouldn't it work if you do that > on realize?
I think we need the information before realize, but I'll double check. In any case the probe is safe to call and free of side-effects. (If it fails we can stash a flag that we didn't manage to probe, which realize can check.) >> Right, that was my question -- are we guaranteed that anything >> that calls object_new(cpu) does it with a lock? > > object_new() itself doesn't seem to be thread-safe (see > type_initialize()), so I'm pretty sure there shouldn't be any > object_new() calls in QEMU without the BQL being held. Cool. thanks -- PMM
