[PATCH v2 2/6] iommufd/hw_pagetable: Use domain_alloc_user op for domain allocation

Yi Liu
2023-09-28T07:15:39Z

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 <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@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