vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()

Every caller has a readily available vfio_device pointer, use that instead
of passing in a generic struct device. The struct vfio_device already
contains the group we need so this avoids complexity, extra refcountings,
and a confusing lifecycle model.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 16 insertions, 30 deletions

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index cb4730756510..0f85e789fbd3 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -2134,7 +2134,7 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
 /*
  * Pin a set of guest PFNs and return their associated host PFNs for local
  * domain only.
- * @dev [in]     : device
+ * @device [in]  : device
  * @user_pfn [in]: array of user/guest PFNs to be pinned.
  * @npage [in]   : count of elements in user_pfn array.  This count should not
  *		   be greater VFIO_PIN_PAGES_MAX_ENTRIES.
@@ -2142,32 +2142,26 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
  * @phys_pfn[out]: array of host PFNs
  * Return error or number of pages pinned.
  */
-int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
-		   int prot, unsigned long *phys_pfn)
+int vfio_pin_pages(struct vfio_device *device, unsigned long *user_pfn,
+		   int npage, int prot, unsigned long *phys_pfn)
 {
 	struct vfio_container *container;
-	struct vfio_group *group;
+	struct vfio_group *group = device->group;
 	struct vfio_iommu_driver *driver;
 	int ret;
 
-	if (!dev || !user_pfn || !phys_pfn || !npage)
+	if (!user_pfn || !phys_pfn || !npage)
 		return -EINVAL;
 
 	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
 		return -E2BIG;
 
-	group = vfio_group_get_from_dev(dev);
-	if (!group)
-		return -ENODEV;
-
-	if (group->dev_counter > 1) {
-		ret = -EINVAL;
-		goto err_pin_pages;
-	}
+	if (group->dev_counter > 1)
+		return -EINVAL;
 
 	ret = vfio_group_add_container_user(group);
 	if (ret)
-		goto err_pin_pages;
+		return ret;
 
 	container = group->container;
 	driver = container->iommu_driver;
@@ -2180,43 +2174,37 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
 
 	vfio_group_try_dissolve_container(group);
 
-err_pin_pages:
-	vfio_group_put(group);
 	return ret;
 }
 EXPORT_SYMBOL(vfio_pin_pages);
 
 /*
  * Unpin set of host PFNs for local domain only.
- * @dev [in]     : device
+ * @device [in]  : device
  * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
  *		   PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
  * @npage [in]   : count of elements in user_pfn array.  This count should not
  *                 be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
  * Return error or number of pages unpinned.
  */
-int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
+int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
+		     int npage)
 {
 	struct vfio_container *container;
-	struct vfio_group *group;
 	struct vfio_iommu_driver *driver;
 	int ret;
 
-	if (!dev || !user_pfn || !npage)
+	if (!user_pfn || !npage)
 		return -EINVAL;
 
 	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
 		return -E2BIG;
 
-	group = vfio_group_get_from_dev(dev);
-	if (!group)
-		return -ENODEV;
-
-	ret = vfio_group_add_container_user(group);
+	ret = vfio_group_add_container_user(device->group);
 	if (ret)
-		goto err_unpin_pages;
+		return ret;
 
-	container = group->container;
+	container = device->group->container;
 	driver = container->iommu_driver;
 	if (likely(driver && driver->ops->unpin_pages))
 		ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
@@ -2224,10 +2212,8 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
 	else
 		ret = -ENOTTY;
 
-	vfio_group_try_dissolve_container(group);
+	vfio_group_try_dissolve_container(device->group);
 
-err_unpin_pages:
-	vfio_group_put(group);
 	return ret;
 }
 EXPORT_SYMBOL(vfio_unpin_pages);