[PULL 0/2] Fixes for vfio-ccw

[PULL 0/2] Fixes for vfio-ccw

[Cornelia Huck]

The following changes since commit 1877888d0ad21858693d8a5594734b125a068638:

  MAINTAINERS: Add vfio-ccw maintainers (2017-03-31 12:55:12 +0200)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20170413

for you to fetch changes up to 129cc19a94513081e9250323cd57e12ed48b3613:

  vfio: ccw: improve error handling for vfio_ccw_mdev_remove (2017-04-12 12:34:17 +0200)

----------------------------------------------------------------
Two fixes for the new vfio-ccw support.

----------------------------------------------------------------

Dong Jia Shi (2):
  vfio: ccw: remove unnecessary NULL checks of a pointer
  vfio: ccw: improve error handling for vfio_ccw_mdev_remove

 drivers/s390/cio/vfio_ccw_fsm.c |  6 +-----
 drivers/s390/cio/vfio_ccw_ops.c | 34 ++++++----------------------------
 2 files changed, 7 insertions(+), 33 deletions(-)

-- 
2.11.0

[PULL 1/2] vfio: ccw: remove unnecessary NULL checks of a pointer

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>

Remove several unnecessary checks for the @private pointer, since it
can never be NULL in these places.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170412090816.79108-2-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/s390/cio/vfio_ccw_fsm.c |  6 +-----
 drivers/s390/cio/vfio_ccw_ops.c | 17 -----------------
 2 files changed, 1 insertion(+), 22 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 55b6cc55758e..80a0559cd7ce 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -161,12 +161,8 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 static void fsm_irq(struct vfio_ccw_private *private,
 		    enum vfio_ccw_event event)
 {
-	struct irb *irb;
+	struct irb *irb = this_cpu_ptr(&cio_irb);
 
-	if (!private)
-		return;
-
-	irb = this_cpu_ptr(&cio_irb);
 	memcpy(&private->irb, irb, sizeof(*irb));
 
 	queue_work(vfio_ccw_work_q, &private->io_work);
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index b2e615404034..55d0c87e73c3 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -19,9 +19,6 @@ static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
 	int ret;
 
 	private = dev_get_drvdata(mdev_parent_dev(mdev));
-	if (!private)
-		return -ENODEV;
-
 	sch = private->sch;
 	/*
 	 * TODO:
@@ -49,9 +46,6 @@ static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
 	struct vfio_ccw_private *private =
 		container_of(nb, struct vfio_ccw_private, nb);
 
-	if (!private)
-		return NOTIFY_STOP;
-
 	/*
 	 * Vendor drivers MUST unpin pages in response to an
 	 * invalidation.
@@ -134,9 +128,6 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 		dev_get_drvdata(mdev_parent_dev(mdev));
 	int ret;
 
-	if (!private)
-		goto out;
-
 	if ((private->state == VFIO_CCW_STATE_NOT_OPER) ||
 	    (private->state == VFIO_CCW_STATE_STANDBY))
 		goto out;
@@ -187,9 +178,6 @@ static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
 		return -EINVAL;
 
 	private = dev_get_drvdata(mdev_parent_dev(mdev));
-	if (!private)
-		return -ENODEV;
-
 	region = &private->io_region;
 	if (copy_to_user(buf, (void *)region + *ppos, count))
 		return -EFAULT;
@@ -209,8 +197,6 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
 		return -EINVAL;
 
 	private = dev_get_drvdata(mdev_parent_dev(mdev));
-	if (!private)
-		return -ENODEV;
 	if (private->state != VFIO_CCW_STATE_IDLE)
 		return -EACCES;
 
@@ -274,9 +260,6 @@ static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
 		return -EINVAL;
 
 	private = dev_get_drvdata(mdev_parent_dev(mdev));
-	if (!private)
-		return -ENODEV;
-
 	ctx = &private->io_trigger;
 
 	switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
-- 
2.11.0

[PULL 2/2] vfio: ccw: improve error handling for vfio_ccw_mdev_remove

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>

When vfio_ccw_mdev_reset fails during the remove process of the mdev,
the current implementation simply returns.

The failure indicates that the subchannel device is in a NOT_OPER state,
thus the right thing to do should be removing the mdev.

While we are at here, reverse the condition check to make the code more
concise and readable.

Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170412090816.79108-3-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/s390/cio/vfio_ccw_ops.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 55d0c87e73c3..e72abbc18ee3 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -126,19 +126,14 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 {
 	struct vfio_ccw_private *private =
 		dev_get_drvdata(mdev_parent_dev(mdev));
-	int ret;
-
-	if ((private->state == VFIO_CCW_STATE_NOT_OPER) ||
-	    (private->state == VFIO_CCW_STATE_STANDBY))
-		goto out;
-
-	ret = vfio_ccw_mdev_reset(mdev);
-	if (ret)
-		return ret;
 
-	private->state = VFIO_CCW_STATE_STANDBY;
+	if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
+	    (private->state != VFIO_CCW_STATE_STANDBY)) {
+		if (!vfio_ccw_mdev_reset(mdev))
+			private->state = VFIO_CCW_STATE_STANDBY;
+		/* The state will be NOT_OPER on error. */
+	}
 
-out:
 	private->mdev = NULL;
 	atomic_inc(&private->avail);
 
-- 
2.11.0

Re: [PULL 0/2] Fixes for vfio-ccw

[Cornelia Huck]

On Thu, 13 Apr 2017 12:57:46 +0200
Cornelia Huck <cornelia.huck@de.ibm.com> wrote:

> The following changes since commit 1877888d0ad21858693d8a5594734b125a068638:
> 
>   MAINTAINERS: Add vfio-ccw maintainers (2017-03-31 12:55:12 +0200)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20170413
> 
> for you to fetch changes up to 129cc19a94513081e9250323cd57e12ed48b3613:
> 
>   vfio: ccw: improve error handling for vfio_ccw_mdev_remove (2017-04-12 12:34:17 +0200)
> 
> ----------------------------------------------------------------
> Two fixes for the new vfio-ccw support.
> 
> ----------------------------------------------------------------
> 
> Dong Jia Shi (2):
>   vfio: ccw: remove unnecessary NULL checks of a pointer
>   vfio: ccw: improve error handling for vfio_ccw_mdev_remove
> 
>  drivers/s390/cio/vfio_ccw_fsm.c |  6 +-----
>  drivers/s390/cio/vfio_ccw_ops.c | 34 ++++++----------------------------
>  2 files changed, 7 insertions(+), 33 deletions(-)
> 

ping