Re: [Qemu-devel] [PATCH/RFC 4/5] s390x/kvm: test whether a cpu is STOPPED when checking "has_work"

Paolo Bonzini
2014-07-28T14:19:49Z

Il 28/07/2014 16:16, David Hildenbrand ha scritto:
> Later, another vcpu might decide to turn that vcpu back on (by e.g. sending a
> SIGP START to that vcpu).
>
> I am not sure if such a mechanism/scenario is applicable to any other arch. They
> all seem to reset the cs->halted flag if they know they are able to run (e.g.
> due to an interrupt) - they have no such thing as "stopped cpus", only
> "halted/waiting cpus".

On x86, INIT_RECEIVED is pretty much a stopped CPU. It can only run
(and receive interrupts) after getting a special startup interrupt ("SIPI").

Paolo