Re: [PATCH v2 9/9] qemu: Place helper processes into the same trusted group

It would need to use SCOPE_THREAD_GROUP, except even that is not sufficient as the helper may have fork+exec'd another helper by this point, and our call will only affect the first process. IOW, to set core scheduling cookies on the helpers, we need to set them upfront at the time we spawn the helper. IOW, during startup, IIUC, we need to fork  a dummy process solely to call PR_SCHED_CORE_CREATE. Then when forking anything else, whether a helper, or QEMU itself, we need to pull the cookie from that dummy process, and then finally kill that dummy process.