[v2,6/6] s390/vfio-ap: do not reset queue removed from host config

Message ID 20231212212522.307893-7-akrowiak@linux.ibm.com
State New
Headers
Series s390/vfio-ap: reset queues removed from guest's AP configuration |

Commit Message

Anthony Krowiak Dec. 12, 2023, 9:25 p.m. UTC
  When a queue is unbound from the vfio_ap device driver, it is reset to
ensure its crypto data is not leaked when it is bound to another device
driver. If the queue is unbound due to the fact that the adapter or domain
was removed from the host's AP configuration, then attempting to reset it
will fail with response code 01 (APID not valid) getting returned from the
reset command. Let's ensure that the queue is assigned to the host's
configuration before resetting it.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Fixes: eeb386aeb5b7 ("s390/vfio-ap: handle config changed and scan complete notification")
Cc: <stable@vger.kernel.org>
---
 drivers/s390/crypto/vfio_ap_ops.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
  

Comments

Jason J. Herne Jan. 10, 2024, 3:44 p.m. UTC | #1
On 12/12/23 4:25 PM, Tony Krowiak wrote:
> When a queue is unbound from the vfio_ap device driver, it is reset to
> ensure its crypto data is not leaked when it is bound to another device
> driver. If the queue is unbound due to the fact that the adapter or domain
> was removed from the host's AP configuration, then attempting to reset it
> will fail with response code 01 (APID not valid) getting returned from the
> reset command. Let's ensure that the queue is assigned to the host's
> configuration before resetting it.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Fixes: eeb386aeb5b7 ("s390/vfio-ap: handle config changed and scan complete notification")
> Cc: <stable@vger.kernel.org>
> ---
>   drivers/s390/crypto/vfio_ap_ops.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index e014108067dc..84decb0d5c97 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -2197,6 +2197,8 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
>   	q = dev_get_drvdata(&apdev->device);
>   	get_update_locks_for_queue(q);
>   	matrix_mdev = q->matrix_mdev;
> +	apid = AP_QID_CARD(q->apqn);
> +	apqi = AP_QID_QUEUE(q->apqn);
>   
>   	if (matrix_mdev) {
>   		/* If the queue is assigned to the guest's AP configuration */
> @@ -2214,8 +2216,16 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
>   		}
>   	}
>   
> -	vfio_ap_mdev_reset_queue(q);
> -	flush_work(&q->reset_work);
> +	/*
> +	 * If the queue is not in the host's AP configuration, then resetting
> +	 * it will fail with response code 01, (APQN not valid); so, let's make
> +	 * sure it is in the host's config.
> +	 */
> +	if (test_bit_inv(apid, (unsigned long *)matrix_dev->info.apm) &&
> +	    test_bit_inv(apqi, (unsigned long *)matrix_dev->info.aqm)) {
> +		vfio_ap_mdev_reset_queue(q);
> +		flush_work(&q->reset_work);
> +	}
>   
>   done:
>   	if (matrix_mdev)

Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
  
Halil Pasic Jan. 11, 2024, 2:17 p.m. UTC | #2
On Tue, 12 Dec 2023 16:25:17 -0500
Tony Krowiak <akrowiak@linux.ibm.com> wrote:

> When a queue is unbound from the vfio_ap device driver, it is reset to
> ensure its crypto data is not leaked when it is bound to another device
> driver. If the queue is unbound due to the fact that the adapter or domain
> was removed from the host's AP configuration, then attempting to reset it
> will fail with response code 01 (APID not valid) getting returned from the
> reset command. Let's ensure that the queue is assigned to the host's
> configuration before resetting it.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>

Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
  

Patch

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e014108067dc..84decb0d5c97 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -2197,6 +2197,8 @@  void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
 	q = dev_get_drvdata(&apdev->device);
 	get_update_locks_for_queue(q);
 	matrix_mdev = q->matrix_mdev;
+	apid = AP_QID_CARD(q->apqn);
+	apqi = AP_QID_QUEUE(q->apqn);
 
 	if (matrix_mdev) {
 		/* If the queue is assigned to the guest's AP configuration */
@@ -2214,8 +2216,16 @@  void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
 		}
 	}
 
-	vfio_ap_mdev_reset_queue(q);
-	flush_work(&q->reset_work);
+	/*
+	 * If the queue is not in the host's AP configuration, then resetting
+	 * it will fail with response code 01, (APQN not valid); so, let's make
+	 * sure it is in the host's config.
+	 */
+	if (test_bit_inv(apid, (unsigned long *)matrix_dev->info.apm) &&
+	    test_bit_inv(apqi, (unsigned long *)matrix_dev->info.aqm)) {
+		vfio_ap_mdev_reset_queue(q);
+		flush_work(&q->reset_work);
+	}
 
 done:
 	if (matrix_mdev)