Re: [Qemu-devel] [PATCH v2 04/11] qemu_flush_work for remote vcpu execution

[Glauber Costa]

On Wed, Dec 02, 2009 at 11:27:53AM -0200, Marcelo Tosatti wrote:
> On Tue, Dec 01, 2009 at 10:51:30AM -0200, Glauber Costa wrote:
> > This function is similar to qemu-kvm's on_vcpu mechanism. Totally 
> > synchronous,
> > and guarantees that a given function will be executed at the specified vcpu.
> > 
> > This patch also convert usage within the breakpoints system
> > 
> > Signed-off-by: Glauber Costa <address@hidden>
> > ---
> 
> > @@ -3436,8 +3441,7 @@ static int tcg_has_work(void);
> >  
> >  static pthread_key_t current_env;
> >  
> > -CPUState *qemu_get_current_env(void);
> > -CPUState *qemu_get_current_env(void)
> > +static CPUState *qemu_get_current_env(void)
> >  {
> >      return pthread_getspecific(current_env);
> >  }
> > @@ -3474,8 +3478,10 @@ static int qemu_init_main_loop(void)
> >  
> >  static void qemu_wait_io_event(CPUState *env)
> >  {
> > -    while (!tcg_has_work())
> > +    while (!tcg_has_work()) {
> 
> This checks all cpus, while for KVM it should check only 
> the current cpu.
> 
> > +        qemu_flush_work(env);
> >          qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000);
> > +    }
> 
> KVM vcpu threads should block SIGUSR1, set the in-kernel signal mask 
> with KVM_SET_SIGNAL_MASK ioctl, and eat the signal in
> qemu_wait_io_event (qemu_flush_work should run after eating
> the signal). Similarly to qemu-kvm's kvm_main_loop_wait.
> 
> Otherwise a vcpu thread can lose a signal (say handle SIGUSR1 when not
> holding qemu_global_mutex before kernel entry).
> 
> I think this the source of the problems patch 8 attempts to fix.

I remember you had patches for both theses fixes.

Can you resend them, ontop of this series?