vfio: Refactor dma APIs for emulated devices

To use group helpers instead of opening group related code in the
API. This prepares moving group specific code out of vfio_main.c.

Link: https://lore.kernel.org/r/20221201145535.589687-10-yi.l.liu@intel.comReviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/vfio/container.c

@@ -540,10 +540,12 @@ void vfio_group_unuse_container(struct vfio_group *group)
 	fput(group->opened_file);
 }
 
-int vfio_container_pin_pages(struct vfio_container *container,
-			     struct iommu_group *iommu_group, dma_addr_t iova,
-			     int npage, int prot, struct page **pages)
+int vfio_device_container_pin_pages(struct vfio_device *device,
+				    dma_addr_t iova, int npage,
+				    int prot, struct page **pages)
 {
+	struct vfio_container *container = device->group->container;
+	struct iommu_group *iommu_group = device->group->iommu_group;
 	struct vfio_iommu_driver *driver = container->iommu_driver;
 
 	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
@@ -555,9 +557,11 @@ int vfio_container_pin_pages(struct vfio_container *container,
 				      npage, prot, pages);
 }
 
-void vfio_container_unpin_pages(struct vfio_container *container,
-				dma_addr_t iova, int npage)
+void vfio_device_container_unpin_pages(struct vfio_device *device,
+				       dma_addr_t iova, int npage)
 {
+	struct vfio_container *container = device->group->container;
+
 	if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES))
 		return;
 
@@ -565,9 +569,11 @@ void vfio_container_unpin_pages(struct vfio_container *container,
 						  npage);
 }
 
-int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
-			  void *data, size_t len, bool write)
+int vfio_device_container_dma_rw(struct vfio_device *device,
+				 dma_addr_t iova, void *data,
+				 size_t len, bool write)
 {
+	struct vfio_container *container = device->group->container;
 	struct vfio_iommu_driver *driver = container->iommu_driver;
 
 	if (unlikely(!driver || !driver->ops->dma_rw))

drivers/vfio/vfio.h

@@ -122,13 +122,14 @@ int vfio_container_attach_group(struct vfio_container *container,
 void vfio_group_detach_container(struct vfio_group *group);
 void vfio_device_container_register(struct vfio_device *device);
 void vfio_device_container_unregister(struct vfio_device *device);
-int vfio_container_pin_pages(struct vfio_container *container,
-			     struct iommu_group *iommu_group, dma_addr_t iova,
-			     int npage, int prot, struct page **pages);
-void vfio_container_unpin_pages(struct vfio_container *container,
-				dma_addr_t iova, int npage);
-int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
-			  void *data, size_t len, bool write);
+int vfio_device_container_pin_pages(struct vfio_device *device,
+				    dma_addr_t iova, int npage,
+				    int prot, struct page **pages);
+void vfio_device_container_unpin_pages(struct vfio_device *device,
+				       dma_addr_t iova, int npage);
+int vfio_device_container_dma_rw(struct vfio_device *device,
+				 dma_addr_t iova, void *data,
+				 size_t len, bool write);
 
 int __init vfio_container_init(void);
 void vfio_container_cleanup(void);
@@ -166,22 +167,21 @@ static inline void vfio_device_container_unregister(struct vfio_device *device)
 {
 }
 
-static inline int vfio_container_pin_pages(struct vfio_container *container,
-					   struct iommu_group *iommu_group,
-					   dma_addr_t iova, int npage, int prot,
-					   struct page **pages)
+static inline int vfio_device_container_pin_pages(struct vfio_device *device,
+						  dma_addr_t iova, int npage,
+						  int prot, struct page **pages)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline void vfio_container_unpin_pages(struct vfio_container *container,
-					      dma_addr_t iova, int npage)
+static inline void vfio_device_container_unpin_pages(struct vfio_device *device,
+						     dma_addr_t iova, int npage)
 {
 }
 
-static inline int vfio_container_dma_rw(struct vfio_container *container,
-					dma_addr_t iova, void *data, size_t len,
-					bool write)
+static inline int vfio_device_container_dma_rw(struct vfio_device *device,
+					       dma_addr_t iova, void *data,
+					       size_t len, bool write)
 {
 	return -EOPNOTSUPP;
 }

drivers/vfio/vfio_main.c

@@ -1938,6 +1938,11 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
 }
 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
 
+static bool vfio_device_has_container(struct vfio_device *device)
+{
+	return device->group->container;
+}
+
 /*
  * Pin contiguous user pages and return their associated host pages for local
  * domain only.
@@ -1950,7 +1955,7 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
  * Return error or number of pages pinned.
  *
  * A driver may only call this function if the vfio_device was created
- * by vfio_register_emulated_iommu_dev() due to vfio_container_pin_pages().
+ * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages().
  */
 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
 		   int npage, int prot, struct page **pages)
@@ -1958,10 +1963,9 @@ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
 	/* group->container cannot change while a vfio device is open */
 	if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
 		return -EINVAL;
-	if (device->group->container)
-		return vfio_container_pin_pages(device->group->container,
-						device->group->iommu_group,
-						iova, npage, prot, pages);
+	if (vfio_device_has_container(device))
+		return vfio_device_container_pin_pages(device, iova,
+						       npage, prot, pages);
 	if (device->iommufd_access) {
 		int ret;
 
@@ -1997,9 +2001,8 @@ void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
 	if (WARN_ON(!vfio_assert_device_open(device)))
 		return;
 
-	if (device->group->container) {
-		vfio_container_unpin_pages(device->group->container, iova,
-					   npage);
+	if (vfio_device_has_container(device)) {
+		vfio_device_container_unpin_pages(device, iova, npage);
 		return;
 	}
 	if (device->iommufd_access) {
@@ -2036,9 +2039,9 @@ int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
 	if (!data || len <= 0 || !vfio_assert_device_open(device))
 		return -EINVAL;
 
-	if (device->group->container)
-		return vfio_container_dma_rw(device->group->container, iova,
-					     data, len, write);
+	if (vfio_device_has_container(device))
+		return vfio_device_container_dma_rw(device, iova,
+						    data, len, write);
 
 	if (device->iommufd_access) {
 		unsigned int flags = 0;