Re: [PATCH v10 17/18] iommufd/selftest: Add test ops to test pasid attach/detach

[Nicolin Chen <nicolinc@nvidia.com>]

On Thu, Mar 20, 2025 at 04:17:58PM -0700, Nicolin Chen wrote:
> On Thu, Mar 20, 2025 at 06:47:43AM -0700, Yi Liu wrote:
> > +static int iommufd_test_pasid_check_domain(struct iommufd_ucmd *ucmd,
> > +					   struct iommu_test_cmd *cmd)
> > +{
> > +	struct iommu_domain *attached_domain, *expect_domain = NULL;
> > +	struct iommufd_hw_pagetable *hwpt = NULL;
> > +	struct iommu_attach_handle *handle;
> > +	struct selftest_obj *sobj;
> > +	struct mock_dev *mdev;
> > +	bool result;
> > +	int rc = 0;
> > +
> > +	sobj = iommufd_test_get_selftest_obj(ucmd->ictx, cmd->id);
> > +	if (IS_ERR(sobj))
> > +		return PTR_ERR(sobj);
> > +
> > +	mdev = sobj->idev.mock_dev;
> > +
> > +	handle = iommu_attach_handle_get(mdev->dev.iommu_group,
> > +					 cmd->pasid_check.pasid, 0);
> > +	if (IS_ERR(handle))
> > +		attached_domain = NULL;
> > +	else
> > +		attached_domain = handle->domain;
> > +
> > +	if (cmd->pasid_check.hwpt_id) {
> > +		hwpt = iommufd_get_hwpt(ucmd, cmd->pasid_check.hwpt_id);
> > +		if (IS_ERR(hwpt)) {
> 
> Do we need cmd->pasid_check.hwpt_id to be optional?

Okay. After reading PATCH-18, it looks like what we want is to
verify whether the hwpt is detached or not using hwpt_id=0.

Similar to check_iotlb() and check_cache(), I think this can be:
	/* hwpt_id=0 is to check whether pasid is detached or not */
	if (!attached_domain && !cmd->pasid_check.hwpt_id)
		goto put_and_return_0;

	hwpt = iommufd_get_hwpt(ucmd, cmd->pasid_check.hwpt_id);
	if (IS_ERR())
		goto put_and_return_PTR_ERR;

	if (hwpt->domain != attached_domain)
		rc = -EINVAL;

Also, given that we pass in hwpt_id, let's call it:
iommufd_test_pasid_check_hwpt/IOMMU_TEST_OP_PASID_CHECK_HWPT?

Thanks
Nicolin