[PATCH 2/6] iommufd/hw_pagetable: Use domain_alloc_user op for domain allocation

[Yi Liu]

This makes IOMMUFD to use iommu_domain_alloc_user() for iommu_domain
creation as IOMMUFD needs to support iommu_domain allocation with
parameters from userspace in nested support. If the iommu driver
doesn't provide domain_alloc_user callback then IOMMUFD falls back to
use iommu_domain_alloc().

Suggested-by: Jason Gunthorpe <j...@nvidia.com>
Reviewed-by: Lu Baolu <baolu...@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
Co-developed-by: Nicolin Chen <nicol...@nvidia.com>
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
Signed-off-by: Yi Liu <yi.l....@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c 
b/drivers/iommu/iommufd/hw_pagetable.c
index cf2c1504e20d..48874f896521 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -5,6 +5,7 @@
 #include <linux/iommu.h>
 #include <uapi/linux/iommufd.h>
 
+#include "../iommu-priv.h"
 #include "iommufd_private.h"
 
 void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
@@ -74,6 +75,7 @@ struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
                           struct iommufd_device *idev, bool immediate_attach)
 {
+       const struct iommu_ops *ops = dev_iommu_ops(idev->dev);
        struct iommufd_hw_pagetable *hwpt;
        int rc;
 
@@ -88,10 +90,19 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct 
iommufd_ioas *ioas,
        refcount_inc(&ioas->obj.users);
        hwpt->ioas = ioas;
 
-       hwpt->domain = iommu_domain_alloc(idev->dev->bus);
-       if (!hwpt->domain) {
-               rc = -ENOMEM;
-               goto out_abort;
+       if (ops->domain_alloc_user) {
+               hwpt->domain = ops->domain_alloc_user(idev->dev, 0);
+               if (IS_ERR(hwpt->domain)) {
+                       rc = PTR_ERR(hwpt->domain);
+                       hwpt->domain = NULL;
+                       goto out_abort;
+               }
+       } else {
+               hwpt->domain = iommu_domain_alloc(idev->dev->bus);
+               if (!hwpt->domain) {
+                       rc = -ENOMEM;
+                       goto out_abort;
+               }
        }
 
        /*
-- 
2.34.1