vfio: Make vfio_container optionally compiled

Add a kconfig CONFIG_VFIO_CONTAINER that controls compiling the container
code. If 'n' then only iommufd will provide the container service. All the
support for vfio iommu drivers, including type1, will not be built.

This allows a compilation check that no inappropriate dependencies between
the device/group and container have been created.

Link: https://lore.kernel.org/r/9-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index b1ef84249637..ce5fe3fc493b 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -55,7 +55,9 @@ struct vfio_group {
 	struct list_head		device_list;
 	struct mutex			device_lock;
 	struct list_head		vfio_next;
+#if IS_ENABLED(CONFIG_VFIO_CONTAINER)
 	struct list_head		container_next;
+#endif
 	enum vfio_group_type		type;
 	struct mutex			group_lock;
 	struct kvm			*kvm;
@@ -64,6 +66,7 @@ struct vfio_group {
 	struct iommufd_ctx		*iommufd;
 };
 
+#if IS_ENABLED(CONFIG_VFIO_CONTAINER)
 /* events for the backend driver notify callback */
 enum vfio_iommu_notify_type {
 	VFIO_IOMMU_CONTAINER_CLOSE = 0,
@@ -129,6 +132,68 @@ int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
 
 int __init vfio_container_init(void);
 void vfio_container_cleanup(void);
+#else
+static inline struct vfio_container *
+vfio_container_from_file(struct file *filep)
+{
+	return NULL;
+}
+
+static inline int vfio_group_use_container(struct vfio_group *group)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void vfio_group_unuse_container(struct vfio_group *group)
+{
+}
+
+static inline int vfio_container_attach_group(struct vfio_container *container,
+					      struct vfio_group *group)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void vfio_group_detach_container(struct vfio_group *group)
+{
+}
+
+static inline void vfio_device_container_register(struct vfio_device *device)
+{
+}
+
+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)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void vfio_container_unpin_pages(struct vfio_container *container,
+					      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)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int vfio_container_init(void)
+{
+	return 0;
+}
+static inline void vfio_container_cleanup(void)
+{
+}
+#endif
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
 int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);