Re: [PATCH v9 13/14] iommu: Improve iopf_queue_remove_device()

[Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>]

On 1/6/24 12:25 AM, Jason Gunthorpe wrote:
> On Wed, Dec 20, 2023 at 09:23:31AM +0800, Lu Baolu wrote:
> > -int iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev)
> > +void iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev)
> >   {
> > -	int ret = 0;
> >   	struct iopf_fault *iopf, *next;
> > +	struct iommu_page_response resp;
> >   	struct dev_iommu *param = dev->iommu;
> >   	struct iommu_fault_param *fault_param;
> > +	const struct iommu_ops *ops = dev_iommu_ops(dev);
> >   
> >   	mutex_lock(&queue->lock);
> >   	mutex_lock(&param->lock);
> >   	fault_param = rcu_dereference_check(param->fault_param,
> >   					    lockdep_is_held(&param->lock));
> > -	if (!fault_param) {
> > -		ret = -ENODEV;
> > -		goto unlock;
> > -	}
> > -
> > -	if (fault_param->queue != queue) {
> > -		ret = -EINVAL;
> > -		goto unlock;
> > -	}
> >   
> > -	if (!list_empty(&fault_param->faults)) {
> > -		ret = -EBUSY;
> > +	if (WARN_ON(!fault_param || fault_param->queue != queue))
> >   		goto unlock;
> > -	}
> > -
> > -	list_del(&fault_param->queue_list);
> >   
> > -	/* Just in case some faults are still stuck */
> > +	mutex_lock(&fault_param->lock);
> >   	list_for_each_entry_safe(iopf, next, &fault_param->partial, list)
> >   		kfree(iopf);
> >   
> > +	list_for_each_entry_safe(iopf, next, &fault_param->faults, list) {
> > +		memset(&resp, 0, sizeof(struct iommu_page_response));
> > +		resp.pasid = iopf->fault.prm.pasid;
> > +		resp.grpid = iopf->fault.prm.grpid;
> > +		resp.code = IOMMU_PAGE_RESP_INVALID;
>
> I would probably move the resp and iopf variables into here:
>
> 		struct iopf_fault *iopf = &group->last_fault;
> 		struct iommu_page_response resp = {
> 			.pasid = iopf->fault.prm.pasid,
> 			.grpid = iopf->fault.prm.grpid,
> 			.code = IOMMU_PAGE_RESP_INVALID
> 		};
>
> (and call the other one partial_iopf)

Yours looks better. Done.

> But this looks fine either way
>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Thank you very much!

Best regards,
baolu