Re: [Qemu-devel] [PATCH] ipmi: do not take/drop iothread lock

[Corey Minyard]

On 01/26/2016 10:21 AM, Michael S. Tsirkin wrote:
> On Tue, Jan 26, 2016 at 05:15:53PM +0100, Paolo Bonzini wrote:
> > This is not necessary and actually causes a hang; it was probably copied
> > and pasted from KVM code, that is one of the very few places that run
> > outside iothread lock.
> >
> > Signed-off-by: Paolo Bonzini <address@hidden>
> Makes sense. I wonder how hard would it be to have a test to catch this.

The IPMI side would be easy for me, but I don't know how to handle 
catching the NMI.

-corey

> > ---
> >   hw/ipmi/ipmi.c | 2 --
> >   1 file changed, 2 deletions(-)
> >
> > diff --git a/hw/ipmi/ipmi.c b/hw/ipmi/ipmi.c
> > index 52aba1e..fcba0ca 100644
> > --- a/hw/ipmi/ipmi.c
> > +++ b/hw/ipmi/ipmi.c
> > @@ -50,9 +50,7 @@ static int ipmi_do_hw_op(IPMIInterface *s, enum ipmi_op op, 
> > int checkonly)
> >           if (checkonly) {
> >               return 0;
> >           }
> > -        qemu_mutex_lock_iothread();
> >           qmp_inject_nmi(NULL);
> > -        qemu_mutex_unlock_iothread();
> >           return 0;
> >   
> >       case IPMI_POWERCYCLE_CHASSIS:
> > --
> > 2.5.0