Re: [Qemu-devel] [s390] possible deadlock in handle_sigp?

[Christian Borntraeger]

On 09/12/2016 06:44 PM, Paolo Bonzini wrote:
> I think that two CPUs doing reciprocal SIGPs could in principle end up
> waiting on each other to complete their run_on_cpu.  If the SIGP has to
> be synchronous the fix is not trivial (you'd have to put the CPU in a
> state similar to cpu->halted = 1), otherwise it's enough to replace
> run_on_cpu with async_run_on_cpu.

IIRC the sigps are supossed to be serialized by the big QEMU lock. WIll 
have a look.