Messages in this thread | | | Subject | Re: [PATCH 01/10] vfio: ccw: Moving state change out of IRQ context | From | Pierre Morel <> | Date | Tue, 24 Apr 2018 10:40:56 +0200 |
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On 24/04/2018 08:54, Dong Jia Shi wrote: > * Pierre Morel <pmorel@linux.vnet.ibm.com> [2018-04-19 16:48:04 +0200]: > > [...] > >> @@ -94,9 +83,15 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) >> static void vfio_ccw_sch_irq(struct subchannel *sch) >> { >> struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); >> + struct irb *irb = this_cpu_ptr(&cio_irb); >> >> inc_irq_stat(IRQIO_CIO); >> - vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT); >> + memcpy(&private->irb, irb, sizeof(*irb)); >> + >> + WARN_ON(work_pending(&private->io_work)); > Hmm, why do we need this?
The current design insure that we have not two concurrent SSCH requests. How ever I want here to track spurious interrupt. If we implement cancel, halt or clear requests, we also may trigger (AFAIU) a second interrupts depending on races between instructions, controller and device.
We do not need it strongly.
> >> + queue_work(vfio_ccw_work_q, &private->io_work); >> + if (private->completion) >> + complete(private->completion); >> } >> >> static int vfio_ccw_sch_probe(struct subchannel *sch) > [...] >
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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