[RFC 4/7] iommufd: Support attach/replace for SIOV virtual device {dev, pasid}

[Yi Liu]

From: Kevin Tian <kevin.tian@xxxxxxxxx>

SIOV devices allows driver to tag different PASIDs for the virtual devices
within it. Such driver should call iommufd_device_bind_pasid() to connect
the pasid of the device to iommufd, and then driver is able to attach the
virtual device to IOAS/HWPT with the iommufd_device_attach() API.

Unlike physical devices, for SIOV virtual devices, iommufd_device_attach()
eventually uses the idev->default_pasid when the virtual device is attached
to an IOAS/HWPT. Also, there is no need to do immediate_attach per iommu
domain allocation in the attach/replace path if any iommu domain allocation
happens since the attach/replace is eventually pasid attach/replace.

Signed-off-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/iommu/iommufd/device.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 35c1419ee96b..4882e3106b2e 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -841,7 +841,11 @@ int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id)
 		.pasid = IOMMU_PASID_INVALID
 	};
 
-	rc = iommufd_device_change_pt(idev, pt_id, &data);
+	if (idev->igroup)
+		rc = iommufd_device_change_pt(idev, pt_id, &data);
+	else
+		/* SIOV device follows generic pasid attach flow */
+		rc = iommufd_device_pasid_attach(idev, idev->default_pasid, pt_id);
 	if (rc)
 		return rc;
 
@@ -876,7 +880,12 @@ int iommufd_device_replace(struct iommufd_device *idev, u32 *pt_id)
 		.pasid = IOMMU_PASID_INVALID
 	};
 
-	return iommufd_device_change_pt(idev, pt_id, &data);
+	if (idev->igroup) {
+		return iommufd_device_change_pt(idev, pt_id, &data);
+	} else {
+		/* SIOV device follows generic pasid replace flow */
+		return iommufd_device_pasid_replace(idev, idev->default_pasid, pt_id);
+	}
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_device_replace, IOMMUFD);
 
@@ -891,8 +900,12 @@ void iommufd_device_detach(struct iommufd_device *idev)
 {
 	struct iommufd_hw_pagetable *hwpt;
 
-	hwpt = iommufd_hw_pagetable_detach(idev);
-	iommufd_hw_pagetable_put(idev->ictx, hwpt);
+	if (idev->igroup) {
+		hwpt = iommufd_hw_pagetable_detach(idev);
+		iommufd_hw_pagetable_put(idev->ictx, hwpt);
+	} else {
+		iommufd_device_pasid_detach(idev, idev->default_pasid);
+	}
 	refcount_dec(&idev->obj.users);
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_device_detach, IOMMUFD);
-- 
2.34.1