Re: [PATCH V5 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa

["Zhu, Lingshan" <lingshan.zhu@intel.com>]

On 8/5/2020 4:06 PM, Jason Wang wrote:
>
> On 2020/7/31 下午2:55, Zhu Lingshan wrote:
>> +static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
>> +{
>> +    struct vhost_virtqueue *vq = &v->vqs[qid];
>> +    const struct vdpa_config_ops *ops = v->vdpa->config;
>> +    struct vdpa_device *vdpa = v->vdpa;
>> +    int ret, irq;
>> +
>> +    spin_lock(&vq->call_ctx.ctx_lock);
>> +    irq = ops->get_vq_irq(vdpa, qid);
>
>
> Btw, this assumes that get_vq_irq is mandatory. This looks wrong since 
> there's no guarantee that the vDPA device driver can see irq. And this 
> break vdpa simulator.
>
> Let's add a check and make it optional by document this assumption in 
> the vdpa.h.
fix soon. Thanks!
>
> Thanks
>
>
>> +    if (!vq->call_ctx.ctx || irq < 0) {
>> +        spin_unlock(&vq->call_ctx.ctx_lock);
>> +        return;
>> +    }
>> +
>