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

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