Re: [PATCH V4 0/9] rework on the IRQ hardening of virtio

[Halil Pasic]

On Wed, 11 May 2022 10:22:59 +0800
Jason Wang <jasowang@xxxxxxxxxx> wrote:

> >        CPU0
> >        ----
> >   lock(&vcdev->irq_lock);
> >   <Interrupt>
> >     lock(&vcdev->irq_lock);
> >
> >  *** DEADLOCK ***  
> 
> It looks to me we need to use write_lock_irq()/write_unlock_irq() to
> do the synchronization.
> 
> And we probably need to keep the
> read_lock_irqsave()/read_lock_irqrestore() logic since I can see the
> virtio_ccw_int_handler() to be called from process context (e.g from
> the io_subchannel_quiesce()).
> 

Sounds correct.

Regards,
Halil