vfio-mdev: Make mdev_device private and abstract interfaces

Abstract access to mdev_device so that we can define which interfaces
are public rather than relying on comments in the structure.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -166,7 +166,7 @@ static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
 
 static void gvt_cache_remove(struct intel_vgpu *vgpu, gfn_t gfn)
 {
-	struct device *dev = &vgpu->vdev.mdev->dev;
+	struct device *dev = mdev_dev(vgpu->vdev.mdev);
 	struct gvt_dma *this;
 	unsigned long g1;
 	int rc;
@@ -195,7 +195,7 @@ static void gvt_cache_destroy(struct intel_vgpu *vgpu)
 {
 	struct gvt_dma *dma;
 	struct rb_node *node = NULL;
-	struct device *dev = &vgpu->vdev.mdev->dev;
+	struct device *dev = mdev_dev(vgpu->vdev.mdev);
 	unsigned long gfn;
 
 	mutex_lock(&vgpu->vdev.cache_lock);
@@ -418,7 +418,7 @@ static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
 	mdev_set_drvdata(mdev, vgpu);
 
 	gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
-		     dev_name(&mdev->dev));
+		     dev_name(mdev_dev(mdev)));
 	return 0;
 }
 
@@ -482,7 +482,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
 	vgpu->vdev.group_notifier.notifier_call = intel_vgpu_group_notifier;
 
 	events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
-	ret = vfio_register_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, &events,
+	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &events,
 				&vgpu->vdev.iommu_notifier);
 	if (ret != 0) {
 		gvt_err("vfio_register_notifier for iommu failed: %d\n", ret);
@@ -490,7 +490,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
 	}
 
 	events = VFIO_GROUP_NOTIFY_SET_KVM;
-	ret = vfio_register_notifier(&mdev->dev, VFIO_GROUP_NOTIFY, &events,
+	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, &events,
 				&vgpu->vdev.group_notifier);
 	if (ret != 0) {
 		gvt_err("vfio_register_notifier for group failed: %d\n", ret);
@@ -500,7 +500,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
 	return kvmgt_guest_init(mdev);
 
 undo_iommu:
-	vfio_unregister_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY,
+	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 					&vgpu->vdev.iommu_notifier);
 out:
 	return ret;
@@ -513,9 +513,9 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
 	if (!handle_valid(vgpu->handle))
 		return;
 
-	vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_IOMMU_NOTIFY,
+	vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_IOMMU_NOTIFY,
 					&vgpu->vdev.iommu_notifier);
-	vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_GROUP_NOTIFY,
+	vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_GROUP_NOTIFY,
 					&vgpu->vdev.group_notifier);
 
 	info = (struct kvmgt_guest_info *)vgpu->handle;
@@ -1372,7 +1372,7 @@ static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
 		return pfn;
 
 	pfn = INTEL_GVT_INVALID_ADDR;
-	dev = &info->vgpu->vdev.mdev->dev;
+	dev = mdev_dev(info->vgpu->vdev.mdev);
 	rc = vfio_pin_pages(dev, &gfn, 1, IOMMU_READ | IOMMU_WRITE, &pfn);
 	if (rc != 1) {
 		gvt_err("vfio_pin_pages failed for gfn 0x%lx: %d\n", gfn, rc);

drivers/vfio/mdev/mdev_core.c

@@ -36,6 +36,36 @@ struct device *mdev_parent_dev(struct mdev_device *mdev)
 }
 EXPORT_SYMBOL(mdev_parent_dev);
 
+void *mdev_get_drvdata(struct mdev_device *mdev)
+{
+	return mdev->driver_data;
+}
+EXPORT_SYMBOL(mdev_get_drvdata);
+
+void mdev_set_drvdata(struct mdev_device *mdev, void *data)
+{
+	mdev->driver_data = data;
+}
+EXPORT_SYMBOL(mdev_set_drvdata);
+
+struct device *mdev_dev(struct mdev_device *mdev)
+{
+	return &mdev->dev;
+}
+EXPORT_SYMBOL(mdev_dev);
+
+struct mdev_device *mdev_from_dev(struct device *dev)
+{
+	return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
+}
+EXPORT_SYMBOL(mdev_from_dev);
+
+uuid_le mdev_uuid(struct mdev_device *mdev)
+{
+	return mdev->uuid;
+}
+EXPORT_SYMBOL(mdev_uuid);
+
 static int _find_mdev_device(struct device *dev, void *data)
 {
 	struct mdev_device *mdev;

drivers/vfio/mdev/mdev_private.h

@@ -26,6 +26,19 @@ struct mdev_parent {
 	struct list_head type_list;
 };
 
+struct mdev_device {
+	struct device dev;
+	struct mdev_parent *parent;
+	uuid_le uuid;
+	void *driver_data;
+	struct kref ref;
+	struct list_head next;
+	struct kobject *type_kobj;
+};
+
+#define to_mdev_device(dev)	container_of(dev, struct mdev_device, dev)
+#define dev_is_mdev(d)		((d)->bus == &mdev_bus_type)
+
 struct mdev_type {
 	struct kobject kobj;
 	struct kobject *devices_kobj;

include/linux/mdev.h

@@ -13,18 +13,7 @@
 #ifndef MDEV_H
 #define MDEV_H
 
-/* Mediated device */
-struct mdev_device {
-	struct device		dev;
-	struct mdev_parent	*parent;
-	uuid_le			uuid;
-	void			*driver_data;
-
-	/* internal */
-	struct kref		ref;
-	struct list_head	next;
-	struct kobject		*type_kobj;
-};
+struct mdev_device;
 
 /**
  * struct mdev_parent_ops - Structure to be registered for each parent device to
@@ -75,7 +64,6 @@ struct mdev_device {
  * Parent device that support mediated device should be registered with mdev
  * module with mdev_parent_ops structure.
  **/
-
 struct mdev_parent_ops {
 	struct module   *owner;
 	const struct attribute_group **dev_attr_groups;
@@ -129,22 +117,13 @@ struct mdev_driver {
 };
 
 #define to_mdev_driver(drv)	container_of(drv, struct mdev_driver, driver)
-#define to_mdev_device(dev)	container_of(dev, struct mdev_device, dev)
 
-static inline void *mdev_get_drvdata(struct mdev_device *mdev)
-{
-	return mdev->driver_data;
-}
-
-static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
-{
-	mdev->driver_data = data;
-}
+extern void *mdev_get_drvdata(struct mdev_device *mdev);
+extern void mdev_set_drvdata(struct mdev_device *mdev, void *data);
+extern uuid_le mdev_uuid(struct mdev_device *mdev);
 
 extern struct bus_type mdev_bus_type;
 
-#define dev_is_mdev(d) ((d)->bus == &mdev_bus_type)
-
 extern int  mdev_register_device(struct device *dev,
 				 const struct mdev_parent_ops *ops);
 extern void mdev_unregister_device(struct device *dev);
@@ -153,5 +132,7 @@ extern int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
 extern void mdev_unregister_driver(struct mdev_driver *drv);
 
 extern struct device *mdev_parent_dev(struct mdev_device *mdev);
+extern struct device *mdev_dev(struct mdev_device *mdev);
+extern struct mdev_device *mdev_from_dev(struct device *dev);
 
 #endif /* MDEV_H */

samples/vfio-mdev/mtty.c

@@ -164,7 +164,7 @@ static struct mdev_state *find_mdev_state_by_uuid(uuid_le uuid)
 	struct mdev_state *mds;
 
 	list_for_each_entry(mds, &mdev_devices_list, next) {
-		if (uuid_le_cmp(mds->mdev->uuid, uuid) == 0)
+		if (uuid_le_cmp(mdev_uuid(mds->mdev), uuid) == 0)
 			return mds;
 	}
 
@@ -341,7 +341,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 				pr_err("Serial port %d: Fifo level trigger\n",
 					index);
 #endif
-				mtty_trigger_interrupt(mdev_state->mdev->uuid);
+				mtty_trigger_interrupt(
+						mdev_uuid(mdev_state->mdev));
 			}
 		} else {
 #if defined(DEBUG_INTR)
@@ -355,7 +356,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 			 */
 			if (mdev_state->s[index].uart_reg[UART_IER] &
 								UART_IER_RLSI)
-				mtty_trigger_interrupt(mdev_state->mdev->uuid);
+				mtty_trigger_interrupt(
+						mdev_uuid(mdev_state->mdev));
 		}
 		mutex_unlock(&mdev_state->rxtx_lock);
 		break;
@@ -374,7 +376,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 				pr_err("Serial port %d: IER_THRI write\n",
 					index);
 #endif
-				mtty_trigger_interrupt(mdev_state->mdev->uuid);
+				mtty_trigger_interrupt(
+						mdev_uuid(mdev_state->mdev));
 			}
 
 			mutex_unlock(&mdev_state->rxtx_lock);
@@ -445,7 +448,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
 			pr_err("Serial port %d: MCR_OUT2 write\n", index);
 #endif
-			mtty_trigger_interrupt(mdev_state->mdev->uuid);
+			mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
 		}
 
 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
@@ -453,7 +456,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
 			pr_err("Serial port %d: MCR RTS/DTR write\n", index);
 #endif
-			mtty_trigger_interrupt(mdev_state->mdev->uuid);
+			mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
 		}
 		break;
 
@@ -504,7 +507,8 @@ static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
 #endif
 			if (mdev_state->s[index].uart_reg[UART_IER] &
 							 UART_IER_THRI)
-				mtty_trigger_interrupt(mdev_state->mdev->uuid);
+				mtty_trigger_interrupt(
+					mdev_uuid(mdev_state->mdev));
 		}
 		mutex_unlock(&mdev_state->rxtx_lock);
 
@@ -1298,10 +1302,8 @@ static ssize_t
 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
 {
-	struct mdev_device *mdev = to_mdev_device(dev);
-
-	if (mdev)
-		return sprintf(buf, "This is MDEV %s\n", dev_name(&mdev->dev));
+	if (mdev_from_dev(dev))
+		return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
 
 	return sprintf(buf, "\n");
 }