diff mbox series

[v1,4/7] vfio/ccw: move private to mdev lifecycle

Message ID 20221019162135.798901-5-farman@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series vfio-ccw parent rework | expand

Commit Message

Eric Farman Oct. 19, 2022, 4:21 p.m. UTC 
Now that the mdev parent data is split out into its own struct,
it is safe to move the remaining private data to follow the
mdev probe/remove lifecycle. The mdev parent data will remain
where it is, and follow the subchannel and the css driver
interfaces.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 drivers/s390/cio/vfio_ccw_drv.c     | 17 ++---------------
 drivers/s390/cio/vfio_ccw_ops.c     | 26 +++++++++++++-------------
 drivers/s390/cio/vfio_ccw_private.h |  3 +++
 3 files changed, 18 insertions(+), 28 deletions(-)

Comments

Tian, Kevin Nov. 1, 2022, 9:08 a.m. UTC | #1 
> From: Eric Farman <farman@linux.ibm.com>
> Sent: Thursday, October 20, 2022 12:22 AM
> 
> @@ -101,15 +101,20 @@ static int vfio_ccw_mdev_probe(struct
> mdev_device *mdev)
>  {
>  	struct subchannel *sch = to_subchannel(mdev->dev.parent);
>  	struct vfio_ccw_parent *parent = dev_get_drvdata(&sch->dev);
> -	struct vfio_ccw_private *private = dev_get_drvdata(&parent->dev);
> +	struct vfio_ccw_private *private;
>  	int ret;
> 
> -	if (private->state == VFIO_CCW_STATE_NOT_OPER)
> -		return -ENODEV;

Not familiar with ccw but just want to double confirm this removal
is intentional w/o side-effect?

> +	private = vfio_ccw_alloc_private(sch);
> +	if (!private)
> +		return -ENOMEM;
> 
>  	ret = vfio_init_device(&private->vdev, &mdev->dev,
> &vfio_ccw_dev_ops);
> -	if (ret)
> +	if (ret) {
> +		kfree(private);
>  		return ret;
> +	}
> +
> +	dev_set_drvdata(&parent->dev, private);
> 
>  	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
>  			   sch->schid.cssid,
> @@ -123,6 +128,7 @@ static int vfio_ccw_mdev_probe(struct mdev_device
> *mdev)
>  	return 0;
> 
>  err_put_vdev:
> +	dev_set_drvdata(&parent->dev, NULL);

No need to set drvdata to NULL, iiuc
Eric Farman Nov. 1, 2022, 2:05 p.m. UTC | #2 
On Tue, 2022-11-01 at 09:08 +0000, Tian, Kevin wrote:
> > From: Eric Farman <farman@linux.ibm.com>
> > Sent: Thursday, October 20, 2022 12:22 AM
> > 
> > @@ -101,15 +101,20 @@ static int vfio_ccw_mdev_probe(struct
> > mdev_device *mdev)
> >  {
> >         struct subchannel *sch = to_subchannel(mdev->dev.parent);
> >         struct vfio_ccw_parent *parent = dev_get_drvdata(&sch-
> > >dev);
> > -       struct vfio_ccw_private *private = dev_get_drvdata(&parent-
> > >dev);
> > +       struct vfio_ccw_private *private;
> >         int ret;
> > 
> > -       if (private->state == VFIO_CCW_STATE_NOT_OPER)
> > -               return -ENODEV;
> 
> Not familiar with ccw but just want to double confirm this removal
> is intentional w/o side-effect?

Right, it's intentional and fine. The concern previously was re-probing
the mdev when a device had gone into a non-recoverable state and the
private data was left hanging around. With the private now being
cleaned up in mdev_remove instead of the subchannel side, that's no
longer an issue.

> 
> > +       private = vfio_ccw_alloc_private(sch);
> > +       if (!private)
> > +               return -ENOMEM;
> > 
> >         ret = vfio_init_device(&private->vdev, &mdev->dev,
> > &vfio_ccw_dev_ops);
> > -       if (ret)
> > +       if (ret) {
> > +               kfree(private);
> >                 return ret;
> > +       }
> > +
> > +       dev_set_drvdata(&parent->dev, private);
> > 
> >         VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
> >                            sch->schid.cssid,
> > @@ -123,6 +128,7 @@ static int vfio_ccw_mdev_probe(struct
> > mdev_device
> > *mdev)
> >         return 0;
> > 
> >  err_put_vdev:
> > +       dev_set_drvdata(&parent->dev, NULL);
> 
> No need to set drvdata to NULL, iiuc

Fair.
diff mbox series

Patch

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index cc9ed2fd970f..686a9b9f6731 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -146,7 +146,7 @@  static void vfio_ccw_sch_irq(struct subchannel *sch)
 	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
 }
 
-static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
+struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 {
 	struct vfio_ccw_private *private;
 
@@ -157,7 +157,7 @@  static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	return private;
 }
 
-static void vfio_ccw_free_private(struct vfio_ccw_private *private)
+void vfio_ccw_free_private(struct vfio_ccw_private *private)
 {
 	struct vfio_ccw_crw *crw, *temp;
 
@@ -185,7 +185,6 @@  static void vfio_ccw_free_parent(struct device *dev)
 static int vfio_ccw_sch_probe(struct subchannel *sch)
 {
 	struct pmcw *pmcw = &sch->schib.pmcw;
-	struct vfio_ccw_private *private;
 	struct vfio_ccw_parent *parent;
 	int ret = -ENOMEM;
 
@@ -202,14 +201,7 @@  static int vfio_ccw_sch_probe(struct subchannel *sch)
 	parent->dev.release = &vfio_ccw_free_parent;
 	device_initialize(&parent->dev);
 
-	private = vfio_ccw_alloc_private(sch);
-	if (IS_ERR(private)) {
-		put_device(&parent->dev);
-		return PTR_ERR(private);
-	}
-
 	dev_set_drvdata(&sch->dev, parent);
-	dev_set_drvdata(&parent->dev, private);
 
 	parent->mdev_type.sysfs_name = "io";
 	parent->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
@@ -226,9 +218,7 @@  static int vfio_ccw_sch_probe(struct subchannel *sch)
 	return 0;
 
 out_free:
-	dev_set_drvdata(&parent->dev, NULL);
 	dev_set_drvdata(&sch->dev, NULL);
-	vfio_ccw_free_private(private);
 	put_device(&parent->dev);
 	return ret;
 }
@@ -236,13 +226,10 @@  static int vfio_ccw_sch_probe(struct subchannel *sch)
 static void vfio_ccw_sch_remove(struct subchannel *sch)
 {
 	struct vfio_ccw_parent *parent = dev_get_drvdata(&sch->dev);
-	struct vfio_ccw_private *private = dev_get_drvdata(&parent->dev);
 
 	mdev_unregister_parent(&parent->parent);
 
 	dev_set_drvdata(&sch->dev, NULL);
-
-	vfio_ccw_free_private(private);
 	put_device(&parent->dev);
 
 	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 626b8eb3507b..3e627b236241 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -101,15 +101,20 @@  static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 {
 	struct subchannel *sch = to_subchannel(mdev->dev.parent);
 	struct vfio_ccw_parent *parent = dev_get_drvdata(&sch->dev);
-	struct vfio_ccw_private *private = dev_get_drvdata(&parent->dev);
+	struct vfio_ccw_private *private;
 	int ret;
 
-	if (private->state == VFIO_CCW_STATE_NOT_OPER)
-		return -ENODEV;
+	private = vfio_ccw_alloc_private(sch);
+	if (!private)
+		return -ENOMEM;
 
 	ret = vfio_init_device(&private->vdev, &mdev->dev, &vfio_ccw_dev_ops);
-	if (ret)
+	if (ret) {
+		kfree(private);
 		return ret;
+	}
+
+	dev_set_drvdata(&parent->dev, private);
 
 	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
 			   sch->schid.cssid,
@@ -123,6 +128,7 @@  static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 	return 0;
 
 err_put_vdev:
+	dev_set_drvdata(&parent->dev, NULL);
 	vfio_put_device(&private->vdev);
 	return ret;
 }
@@ -132,15 +138,6 @@  static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
 	struct vfio_ccw_private *private =
 		container_of(vdev, struct vfio_ccw_private, vdev);
 
-	/*
-	 * We cannot free vfio_ccw_private here because it includes
-	 * parent info which must be free'ed by css driver.
-	 *
-	 * Use a workaround by memset'ing the core device part and
-	 * then notifying the remove path that all active references
-	 * to this device have been released.
-	 */
-	memset(vdev, 0, sizeof(*vdev));
 	complete(&private->release_comp);
 }
 
@@ -157,6 +154,7 @@  static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 
 	vfio_unregister_group_dev(&private->vdev);
 
+	dev_set_drvdata(&parent->dev, NULL);
 	vfio_put_device(&private->vdev);
 	/*
 	 * Wait for all active references on mdev are released so it
@@ -167,6 +165,8 @@  static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 	 * cycle.
 	 */
 	wait_for_completion(&private->release_comp);
+
+	vfio_ccw_free_private(private);
 }
 
 static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index b35940057073..c1959b8bfe86 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -119,6 +119,9 @@  int vfio_ccw_sch_quiesce(struct subchannel *sch);
 void vfio_ccw_sch_io_todo(struct work_struct *work);
 void vfio_ccw_crw_todo(struct work_struct *work);
 
+struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch);
+void vfio_ccw_free_private(struct vfio_ccw_private *private);
+
 extern struct mdev_driver vfio_ccw_mdev_driver;
 
 /*