[PULL 0/1] vfio-ccw: bug fix

[PULL 0/1] vfio-ccw: bug fix

[Cornelia Huck]

The following changes since commit fae764912153065ea55eda47f834e0764a54df94:

  s390/signal: cleanup uapi struct sigaction (2018-04-17 10:36:12 +0200)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20180420

for you to fetch changes up to c25e3c8e91318ddc17261c7dff053e00a213f176:

  vfio: ccw: process ssch with interrupts disabled (2018-04-19 17:29:31 +0200)

----------------------------------------------------------------
A vfio-ccw bug fix (call ssch with interrupts disabled).

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

Cornelia Huck (1):
  vfio: ccw: process ssch with interrupts disabled

 drivers/s390/cio/vfio_ccw_fsm.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

-- 
2.14.3

[PULL 1/1] vfio: ccw: process ssch with interrupts disabled

[Cornelia Huck]

When we call ssch, an interrupt might already be pending once we
return from the START SUBCHANNEL instruction. Therefore we need to
make sure interrupts are disabled while holding the subchannel lock
until after we're done with our processing.

Cc: stable@vger.kernel.org #v4.12+
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_fsm.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index ff6963ad6e39..3c800642134e 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -20,12 +20,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
 	int ccode;
 	__u8 lpm;
 	unsigned long flags;
+	int ret;
 
 	sch = private->sch;
 
 	spin_lock_irqsave(sch->lock, flags);
 	private->state = VFIO_CCW_STATE_BUSY;
-	spin_unlock_irqrestore(sch->lock, flags);
 
 	orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
 
@@ -38,10 +38,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
 		 * Initialize device status information
 		 */
 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
-		return 0;
+		ret = 0;
+		break;
 	case 1:		/* Status pending */
 	case 2:		/* Busy */
-		return -EBUSY;
+		ret = -EBUSY;
+		break;
 	case 3:		/* Device/path not operational */
 	{
 		lpm = orb->cmd.lpm;
@@ -51,13 +53,16 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
 			sch->lpm = 0;
 
 		if (cio_update_schib(sch))
-			return -ENODEV;
-
-		return sch->lpm ? -EACCES : -ENODEV;
+			ret = -ENODEV;
+		else
+			ret = sch->lpm ? -EACCES : -ENODEV;
+		break;
 	}
 	default:
-		return ccode;
+		ret = ccode;
 	}
+	spin_unlock_irqrestore(sch->lock, flags);
+	return ret;
 }
 
 static void fsm_notoper(struct vfio_ccw_private *private,
-- 
2.14.3

Re: [PULL 0/1] vfio-ccw: bug fix

[Martin Schwidefsky]

On Fri, 20 Apr 2018 10:24:03 +0200
Cornelia Huck <cohuck@redhat.com> wrote:

> The following changes since commit fae764912153065ea55eda47f834e0764a54df94:
> 
>   s390/signal: cleanup uapi struct sigaction (2018-04-17 10:36:12 +0200)
> 
> are available in the Git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20180420
> 
> for you to fetch changes up to c25e3c8e91318ddc17261c7dff053e00a213f176:
> 
>   vfio: ccw: process ssch with interrupts disabled (2018-04-19 17:29:31 +0200)
> 
> ----------------------------------------------------------------
> A vfio-ccw bug fix (call ssch with interrupts disabled).
> 
> ----------------------------------------------------------------
> 
> Cornelia Huck (1):
>   vfio: ccw: process ssch with interrupts disabled
> 
>  drivers/s390/cio/vfio_ccw_fsm.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 

This is now queued in s390/linux:fixes for the next please-pull.

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.