kvm: Set up signal mask also for !CONFIG_IOTHREAD Block SIG_IPI, unblock it during KVM_RUN, just like in io-thread mode. It's unused so far, but this infrastructure will be required for self-IPIs and to process SIGBUS plus, in KVM mode, SIGIO and SIGALRM. As Windows doesn't support signal services, we need to provide a stub for the init function. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>