2022-11-02 15:12:11

by Eric Farman

[permalink] [raw]
Subject: [PATCH v2 5/7] vfio/ccw: remove release completion

There's enough separation between the parent and private structs now,
that it is fine to remove the release completion hack.

Signed-off-by: Eric Farman <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
---
drivers/s390/cio/vfio_ccw_ops.c | 14 +-------------
drivers/s390/cio/vfio_ccw_private.h | 3 ---
2 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index e45d4acb109b..8a929a9cf3c6 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -54,7 +54,6 @@ static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
INIT_LIST_HEAD(&private->crw);
INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
- init_completion(&private->release_comp);

private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
GFP_KERNEL);
@@ -137,7 +136,7 @@ static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
struct vfio_ccw_private *private =
container_of(vdev, struct vfio_ccw_private, vdev);

- complete(&private->release_comp);
+ vfio_ccw_free_private(private);
}

static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
@@ -155,17 +154,6 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)

dev_set_drvdata(&parent->dev, NULL);
vfio_put_device(&private->vdev);
- /*
- * Wait for all active references on mdev are released so it
- * is safe to defer kfree() to a later point.
- *
- * TODO: the clean fix is to split parent/mdev info from ccw
- * private structure so each can be managed in its own life
- * 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 747aba5f5272..2278fd38d34e 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -102,7 +102,6 @@ struct vfio_ccw_parent {
* @req_trigger: eventfd ctx for signaling userspace to return device
* @io_work: work for deferral process of I/O handling
* @crw_work: work for deferral process of CRW handling
- * @release_comp: synchronization helper for vfio device release
*/
struct vfio_ccw_private {
struct vfio_device vdev;
@@ -126,8 +125,6 @@ struct vfio_ccw_private {
struct eventfd_ctx *req_trigger;
struct work_struct io_work;
struct work_struct crw_work;
-
- struct completion release_comp;
} __aligned(8);

int vfio_ccw_sch_quiesce(struct subchannel *sch);
--
2.34.1



2022-11-03 23:53:23

by Matthew Rosato

[permalink] [raw]
Subject: Re: [PATCH v2 5/7] vfio/ccw: remove release completion

On 11/2/22 11:01 AM, Eric Farman wrote:
> There's enough separation between the parent and private structs now,
> that it is fine to remove the release completion hack.
>
> Signed-off-by: Eric Farman <[email protected]>
> Reviewed-by: Kevin Tian <[email protected]>

Reviewed-by: Matthew Rosato <[email protected]>

> ---
> drivers/s390/cio/vfio_ccw_ops.c | 14 +-------------
> drivers/s390/cio/vfio_ccw_private.h | 3 ---
> 2 files changed, 1 insertion(+), 16 deletions(-)
>
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
> index e45d4acb109b..8a929a9cf3c6 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -54,7 +54,6 @@ static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
> INIT_LIST_HEAD(&private->crw);
> INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
> INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
> - init_completion(&private->release_comp);
>
> private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
> GFP_KERNEL);
> @@ -137,7 +136,7 @@ static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
> struct vfio_ccw_private *private =
> container_of(vdev, struct vfio_ccw_private, vdev);
>
> - complete(&private->release_comp);
> + vfio_ccw_free_private(private);
> }
>
> static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
> @@ -155,17 +154,6 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
>
> dev_set_drvdata(&parent->dev, NULL);
> vfio_put_device(&private->vdev);
> - /*
> - * Wait for all active references on mdev are released so it
> - * is safe to defer kfree() to a later point.
> - *
> - * TODO: the clean fix is to split parent/mdev info from ccw
> - * private structure so each can be managed in its own life
> - * 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 747aba5f5272..2278fd38d34e 100644
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -102,7 +102,6 @@ struct vfio_ccw_parent {
> * @req_trigger: eventfd ctx for signaling userspace to return device
> * @io_work: work for deferral process of I/O handling
> * @crw_work: work for deferral process of CRW handling
> - * @release_comp: synchronization helper for vfio device release
> */
> struct vfio_ccw_private {
> struct vfio_device vdev;
> @@ -126,8 +125,6 @@ struct vfio_ccw_private {
> struct eventfd_ctx *req_trigger;
> struct work_struct io_work;
> struct work_struct crw_work;
> -
> - struct completion release_comp;
> } __aligned(8);
>
> int vfio_ccw_sch_quiesce(struct subchannel *sch);