vfio: Remove dead code

Now that callers have been updated to use the vfio_device APIs the driver
facing group interface is no longer used, delete it:

- vfio_group_get_external_user_from_dev()
- vfio_group_pin_pages()
- vfio_group_unpin_pages()
- vfio_group_iommu_domain()

--

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Author: jgunthorpe

drivers/vfio/vfio.c

@@ -1947,44 +1947,6 @@ struct vfio_group *vfio_group_get_external_user(struct file *filep)
 }
 EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
 
-/*
- * External user API, exported by symbols to be linked dynamically.
- * The external user passes in a device pointer
- * to verify that:
- *	- A VFIO group is assiciated with the device;
- *	- IOMMU is set for the group.
- * If both checks passed, vfio_group_get_external_user_from_dev()
- * increments the container user counter to prevent the VFIO group
- * from disposal before external user exits and returns the pointer
- * to the VFIO group.
- *
- * When the external user finishes using the VFIO group, it calls
- * vfio_group_put_external_user() to release the VFIO group and
- * decrement the container user counter.
- *
- * @dev [in]	: device
- * Return error PTR or pointer to VFIO group.
- */
-
-struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev)
-{
-	struct vfio_group *group;
-	int ret;
-
-	group = vfio_group_get_from_dev(dev);
-	if (!group)
-		return ERR_PTR(-ENODEV);
-
-	ret = vfio_group_add_container_user(group);
-	if (ret) {
-		vfio_group_put(group);
-		return ERR_PTR(ret);
-	}
-
-	return group;
-}
-EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev);
-
 void vfio_group_put_external_user(struct vfio_group *group)
 {
 	vfio_group_try_dissolve_container(group);
@@ -2218,101 +2180,6 @@ int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
 }
 EXPORT_SYMBOL(vfio_unpin_pages);
 
-/*
- * Pin a set of guest IOVA PFNs and return their associated host PFNs for a
- * VFIO group.
- *
- * The caller needs to call vfio_group_get_external_user() or
- * vfio_group_get_external_user_from_dev() prior to calling this interface,
- * so as to prevent the VFIO group from disposal in the middle of the call.
- * But it can keep the reference to the VFIO group for several calls into
- * this interface.
- * After finishing using of the VFIO group, the caller needs to release the
- * VFIO group by calling vfio_group_put_external_user().
- *
- * @group [in]		: VFIO group
- * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be pinned.
- * @npage [in]		: count of elements in user_iova_pfn array.
- *			  This count should not be greater
- *			  VFIO_PIN_PAGES_MAX_ENTRIES.
- * @prot [in]		: protection flags
- * @phys_pfn [out]	: array of host PFNs
- * Return error or number of pages pinned.
- */
-int vfio_group_pin_pages(struct vfio_group *group,
-			 unsigned long *user_iova_pfn, int npage,
-			 int prot, unsigned long *phys_pfn)
-{
-	struct vfio_container *container;
-	struct vfio_iommu_driver *driver;
-	int ret;
-
-	if (!group || !user_iova_pfn || !phys_pfn || !npage)
-		return -EINVAL;
-
-	if (group->dev_counter > 1)
-		return -EINVAL;
-
-	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
-		return -E2BIG;
-
-	container = group->container;
-	driver = container->iommu_driver;
-	if (likely(driver && driver->ops->pin_pages))
-		ret = driver->ops->pin_pages(container->iommu_data,
-					     group->iommu_group, user_iova_pfn,
-					     npage, prot, phys_pfn);
-	else
-		ret = -ENOTTY;
-
-	return ret;
-}
-EXPORT_SYMBOL(vfio_group_pin_pages);
-
-/*
- * Unpin a set of guest IOVA PFNs for a VFIO group.
- *
- * The caller needs to call vfio_group_get_external_user() or
- * vfio_group_get_external_user_from_dev() prior to calling this interface,
- * so as to prevent the VFIO group from disposal in the middle of the call.
- * But it can keep the reference to the VFIO group for several calls into
- * this interface.
- * After finishing using of the VFIO group, the caller needs to release the
- * VFIO group by calling vfio_group_put_external_user().
- *
- * @group [in]		: vfio group
- * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be unpinned.
- * @npage [in]		: count of elements in user_iova_pfn array.
- *			  This count should not be greater than
- *			  VFIO_PIN_PAGES_MAX_ENTRIES.
- * Return error or number of pages unpinned.
- */
-int vfio_group_unpin_pages(struct vfio_group *group,
-			   unsigned long *user_iova_pfn, int npage)
-{
-	struct vfio_container *container;
-	struct vfio_iommu_driver *driver;
-	int ret;
-
-	if (!group || !user_iova_pfn || !npage)
-		return -EINVAL;
-
-	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
-		return -E2BIG;
-
-	container = group->container;
-	driver = container->iommu_driver;
-	if (likely(driver && driver->ops->unpin_pages))
-		ret = driver->ops->unpin_pages(container->iommu_data,
-					       user_iova_pfn, npage);
-	else
-		ret = -ENOTTY;
-
-	return ret;
-}
-EXPORT_SYMBOL(vfio_group_unpin_pages);
-
-
 /*
  * This interface allows the CPUs to perform some sort of virtual DMA on
  * behalf of the device.
@@ -2516,24 +2383,6 @@ int vfio_unregister_notifier(struct vfio_device *device,
 }
 EXPORT_SYMBOL(vfio_unregister_notifier);
 
-struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group)
-{
-	struct vfio_container *container;
-	struct vfio_iommu_driver *driver;
-
-	if (!group)
-		return ERR_PTR(-EINVAL);
-
-	container = group->container;
-	driver = container->iommu_driver;
-	if (likely(driver && driver->ops->group_iommu_domain))
-		return driver->ops->group_iommu_domain(container->iommu_data,
-						       group->iommu_group);
-
-	return ERR_PTR(-ENOTTY);
-}
-EXPORT_SYMBOL_GPL(vfio_group_iommu_domain);
-
 /*
  * Module/class support
  */

include/linux/vfio.h

@@ -140,8 +140,6 @@ int vfio_mig_get_next_state(struct vfio_device *device,
  */
 extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
 extern void vfio_group_put_external_user(struct vfio_group *group);
-extern struct vfio_group *vfio_group_get_external_user_from_dev(struct device
-								*dev);
 extern bool vfio_external_group_match_file(struct vfio_group *group,
 					   struct file *filep);
 extern int vfio_external_user_iommu_id(struct vfio_group *group);
@@ -154,18 +152,9 @@ extern int vfio_pin_pages(struct vfio_device *device, unsigned long *user_pfn,
 			  int npage, int prot, unsigned long *phys_pfn);
 extern int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
 			    int npage);
-
-extern int vfio_group_pin_pages(struct vfio_group *group,
-				unsigned long *user_iova_pfn, int npage,
-				int prot, unsigned long *phys_pfn);
-extern int vfio_group_unpin_pages(struct vfio_group *group,
-				  unsigned long *user_iova_pfn, int npage);
-
 extern int vfio_dma_rw(struct vfio_device *device, dma_addr_t user_iova,
 		       void *data, size_t len, bool write);
 
-extern struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group);
-
 /* each type has independent events */
 enum vfio_notify_type {
 	VFIO_IOMMU_NOTIFY = 0,