Re: [PATCH v6 13/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU

[Jason Gunthorpe]

On Fri, Jan 24, 2025 at 04:30:42PM -0800, Nicolin Chen wrote:

> @@ -1831,31 +1831,30 @@ static int arm_smmu_handle_event(struct arm_smmu_device *smmu,
>  		return -EOPNOTSUPP;
>  	}

There is still the filter at the top:

	switch (event->id) {
	case EVT_ID_TRANSLATION_FAULT:
	case EVT_ID_ADDR_SIZE_FAULT:
	case EVT_ID_ACCESS_FAULT:
	case EVT_ID_PERMISSION_FAULT:
		break;
	default:
		return -EOPNOTSUPP;
	}

Is that right here or should more event types be forwarded to the
guest?
  
>  	mutex_lock(&smmu->streams_mutex);
[..]
  
> -	ret = iommu_report_device_fault(master->dev, &fault_evt);
> +	if (event->stall) {
> +		ret = iommu_report_device_fault(master->dev, &fault_evt);
> +	} else {
> +		down_read(&master->vmaster_rwsem);

This already holds the streams_mutex across all of this, do you think
we should get rid of the vmaster_rwsem and hold the streams_mutex on
write instead?

Jason