[Qemu-devel] Re: [PATCH v2 13/24] kvm: Set up signal mask also for !CONFIG_IOTHREAD

[Avi Kivity <avi@redhat.com>]

On 02/28/2011 06:16 PM, Jan Kiszka wrote:
> On 2011-02-28 16:55, Avi Kivity wrote:
> >  On 02/01/2011 11:15 PM, Jan Kiszka wrote:
> >>  From: Jan Kiszka<jan.kiszka@siemens.com>
> >>
> >>  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.
> >>
> >
> >  This patch breaks qemu-kvm after merging.  The symptoms are that Windows
> >  XP x64 does not respond when netcat connects to some server in it, via
> >  -net user,hostfwd.  The vcpu thread loops indefinitely on KVM_EXIT_INTR,
> >  which is consistent with signals being messed up.
> >
> >  I verified that 981085dd465c1 merged with ff48eb5fe79ad works,
> >  while 981085dd465c1 merged with ff48eb5fe79ad^ fails.
> >
> >
> >>  diff --git a/cpus.c b/cpus.c
> >>  index 42717ba..a33e470 100644
> >>  --- a/cpus.c
> >>  +++ b/cpus.c
> >>  @@ -231,11 +231,9 @@ fail:
> >>        return err;
> >>    }
> >>
> >>  -#ifdef CONFIG_IOTHREAD
> >>    static void dummy_signal(int sig)
> >>    {
> >>    }
> >>  -#endif
> >>
> >>    #else /* _WIN32 */
> >>
> >>  @@ -267,6 +265,32 @@ static void qemu_event_increment(void)
> >>    #endif /* _WIN32 */
> >>
> >>    #ifndef CONFIG_IOTHREAD
> >>  +static void qemu_kvm_init_cpu_signals(CPUState *env)
> >>  +{
> >>  +#ifndef _WIN32
> >>  +    int r;
> >>  +    sigset_t set;
> >>  +    struct sigaction sigact;
> >>  +
> >>  +    memset(&sigact, 0, sizeof(sigact));
> >>  +    sigact.sa_handler = dummy_signal;
> >>  +    sigaction(SIG_IPI,&sigact, NULL);
> >>  +
> >>  +    sigemptyset(&set);
> >>  +    sigaddset(&set, SIG_IPI);
> >>  +    pthread_sigmask(SIG_BLOCK,&set, NULL);
> >>  +
> >>  +    pthread_sigmask(SIG_BLOCK, NULL,&set);
> >>  +    sigdelset(&set, SIG_IPI);
> >>  +    sigdelset(&set, SIGBUS);
> >>  +    r = kvm_set_signal_mask(env,&set);
> >>  +    if (r) {
> >>  +        fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
> >>  +        exit(1);
> >>  +    }
> >>  +#endif
> >>  +}
> >>  +
> >>    int qemu_init_main_loop(void)
> >>    {
> >>        cpu_set_debug_excp_handler(cpu_debug_handler);
> >>  @@ -292,6 +316,7 @@ void qemu_init_vcpu(void *_env)
> >>                fprintf(stderr, "kvm_init_vcpu failed: %s\n",
> >>  strerror(-r));
> >>                exit(1);
> >>            }
> >>  +        qemu_kvm_init_cpu_signals(env);
>
> Just comment that out as long as qemu-kvm is (mis-)using !IOTHREAD mode.
> I thought it would run before setup_kernel_sigmask, but it's the other
> way around, and then the wrong non-iothread signal setup is applied.

That's what I tried, and it didn't work?!  Maybe I forgot to compile or 
something.

-- 
error compiling committee.c: too many arguments to function