[PATCH v10 12/22] vfio: Record devid in vfio_device_file

[Yi Liu <yi.l.liu@xxxxxxxxx>]

.bind_iommufd() will generate an ID to represent this bond, which is
needed by userspace for further usage. Store devid in vfio_device_file
to avoid passing the pointer in multiple places.

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Tested-by: Terrence Xu <terrence.xu@xxxxxxxxx>
Tested-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Tested-by: Yanting Jiang <yanting.jiang@xxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/vfio/iommufd.c   | 14 ++++++++------
 drivers/vfio/vfio.h      | 10 +++++-----
 drivers/vfio/vfio_main.c |  6 +++---
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index cee81f5910d4..ce7ea27d049a 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -28,17 +28,17 @@ int vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,
 	return 0;
 }
 
-int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
+int vfio_iommufd_bind(struct vfio_device_file *df)
 {
-	u32 device_id;
+	struct vfio_device *vdev = df->device;
+	struct iommufd_ctx *ictx = df->iommufd;
 
 	lockdep_assert_held(&vdev->dev_set->lock);
 
 	if (vdev->noiommu)
-		return vfio_iommufd_emulated_bind(vdev, ictx, &device_id);
+		return vfio_iommufd_emulated_bind(vdev, ictx, &df->devid);
 
-	/* The legacy path has no way to return the device id */
-	return vdev->ops->bind_iommufd(vdev, ictx, &device_id);
+	return vdev->ops->bind_iommufd(vdev, ictx, &df->devid);
 }
 
 int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
@@ -61,8 +61,10 @@ int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
 	return vdev->ops->attach_ioas(vdev, &ioas_id);
 }
 
-void vfio_iommufd_unbind(struct vfio_device *vdev)
+void vfio_iommufd_unbind(struct vfio_device_file *df)
 {
+	struct vfio_device *vdev = df->device;
+
 	lockdep_assert_held(&vdev->dev_set->lock);
 
 	if (vdev->noiommu) {
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index b84fbcdd00aa..8f528612be07 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -24,6 +24,7 @@ struct vfio_device_file {
 	spinlock_t kvm_ref_lock; /* protect kvm field */
 	struct kvm *kvm;
 	struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
+	u32 devid; /* only valid when iommufd is valid */
 };
 
 void vfio_device_put_registration(struct vfio_device *device);
@@ -237,8 +238,8 @@ static inline void vfio_container_cleanup(void)
 #if IS_ENABLED(CONFIG_IOMMUFD)
 int vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,
 				      struct iommufd_ctx *ictx);
-int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
-void vfio_iommufd_unbind(struct vfio_device *device);
+int vfio_iommufd_bind(struct vfio_device_file *df);
+void vfio_iommufd_unbind(struct vfio_device_file *df);
 int vfio_iommufd_compat_attach_ioas(struct vfio_device *device,
 				    struct iommufd_ctx *ictx);
 #else
@@ -249,13 +250,12 @@ vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,
 	return -EOPNOTSUPP;
 }
 
-static inline int vfio_iommufd_bind(struct vfio_device *device,
-				    struct iommufd_ctx *ictx)
+static inline int vfio_iommufd_bind(struct vfio_device_file *fd)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline void vfio_iommufd_unbind(struct vfio_device *device)
+static inline void vfio_iommufd_unbind(struct vfio_device_file *df)
 {
 }
 
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 13afcfac678e..d3e8f480be2c 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -435,7 +435,7 @@ static int vfio_device_first_open(struct vfio_device_file *df)
 		return -ENODEV;
 
 	if (iommufd)
-		ret = vfio_iommufd_bind(device, iommufd);
+		ret = vfio_iommufd_bind(df);
 	else
 		ret = vfio_device_group_use_iommu(device);
 	if (ret)
@@ -450,7 +450,7 @@ static int vfio_device_first_open(struct vfio_device_file *df)
 
 err_unuse_iommu:
 	if (iommufd)
-		vfio_iommufd_unbind(device);
+		vfio_iommufd_unbind(df);
 	else
 		vfio_device_group_unuse_iommu(device);
 err_module_put:
@@ -468,7 +468,7 @@ static void vfio_device_last_close(struct vfio_device_file *df)
 	if (device->ops->close_device)
 		device->ops->close_device(device);
 	if (iommufd)
-		vfio_iommufd_unbind(device);
+		vfio_iommufd_unbind(df);
 	else
 		vfio_device_group_unuse_iommu(device);
 	module_put(device->dev->driver->owner);
-- 
2.34.1