1. Patchew
  2. linux
  3. [PATCH 0/7] improve AP queue reset processing
  4. View patch

[PATCH 3/7] s390/vfio_ap: use TAPQ to verify reset in progress completes

Tony Krowiak posted 7 patches 2 years, 9 months ago
There is a newer version of this series
[PATCH 3/7] s390/vfio_ap: use TAPQ to verify reset in progress completes
Posted by Tony Krowiak 2 years, 9 months ago 
To eliminate the repeated calls to the PQAP(ZAPQ) function to verify that
a reset in progress completed successfully and ensure that error response
codes get appropriately logged, let's call the apq_reset_check() function
when the ZAPQ response code indicates that a reset that is already in
progress.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_ops.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index a5530a46cf31..5bf2d93ae8af 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -33,7 +33,7 @@
 static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable);
 static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
 static const struct vfio_device_ops vfio_ap_matrix_dev_ops;
-static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, unsigned int retry);
+static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q);
 
 /**
  * get_update_locks_for_kvm: Acquire the locks required to dynamically update a
@@ -1632,8 +1632,7 @@ static int apq_reset_check(struct vfio_ap_queue *q)
 	return ret;
 }
 
-static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
-				    unsigned int retry)
+static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
 {
 	struct ap_queue_status status;
 	int ret;
@@ -1648,12 +1647,15 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
 		ret = 0;
 		break;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
-		if (retry--) {
-			msleep(20);
-			goto retry_zapq;
-		}
-		ret = -EBUSY;
-		break;
+		/*
+		 * There is a reset issued by another process in progress. Let's wait
+		 * for that to complete. Since we have no idea whether it was a RAPQ or
+		 * ZAPQ, then if it completes successfully, let's issue the ZAPQ.
+		 */
+		ret = apq_reset_check(q);
+		if (ret)
+			break;
+		goto retry_zapq;
 	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
 	case AP_RESPONSE_CHECKSTOPPED:
@@ -1688,7 +1690,7 @@ static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable)
 	struct vfio_ap_queue *q;
 
 	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
-		ret = vfio_ap_mdev_reset_queue(q, 1);
+		ret = vfio_ap_mdev_reset_queue(q);
 		/*
 		 * Regardless whether a queue turns out to be busy, or
 		 * is not operational, we need to continue resetting
@@ -1931,7 +1933,7 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
 		}
 	}
 
-	vfio_ap_mdev_reset_queue(q, 1);
+	vfio_ap_mdev_reset_queue(q);
 	dev_set_drvdata(&apdev->device, NULL);
 	kfree(q);
 	release_update_locks_for_mdev(matrix_mdev);
-- 
2.31.1
Re: [PATCH 3/7] s390/vfio_ap: use TAPQ to verify reset in progress completes
Posted by Harald Freudenberger 2 years, 9 months ago 
On 2022-12-13 16:44, Tony Krowiak wrote:
> To eliminate the repeated calls to the PQAP(ZAPQ) function to verify 
> that
> a reset in progress completed successfully and ensure that error 
> response
> codes get appropriately logged, let's call the apq_reset_check() 
> function
> when the ZAPQ response code indicates that a reset that is already in
> progress.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> ---
>  drivers/s390/crypto/vfio_ap_ops.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index a5530a46cf31..5bf2d93ae8af 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -33,7 +33,7 @@
>  static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable);
>  static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
>  static const struct vfio_device_ops vfio_ap_matrix_dev_ops;
> -static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, unsigned
> int retry);
> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q);
> 
>  /**
>   * get_update_locks_for_kvm: Acquire the locks required to dynamically 
> update a
> @@ -1632,8 +1632,7 @@ static int apq_reset_check(struct vfio_ap_queue 
> *q)
>  	return ret;
>  }
> 
> -static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
> -				    unsigned int retry)
> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
>  {
>  	struct ap_queue_status status;
>  	int ret;
> @@ -1648,12 +1647,15 @@ static int vfio_ap_mdev_reset_queue(struct
> vfio_ap_queue *q,
>  		ret = 0;
>  		break;
>  	case AP_RESPONSE_RESET_IN_PROGRESS:
> -		if (retry--) {
> -			msleep(20);
> -			goto retry_zapq;
> -		}
> -		ret = -EBUSY;
> -		break;
> +		/*
> +		 * There is a reset issued by another process in progress. Let's 
> wait
> +		 * for that to complete. Since we have no idea whether it was a RAPQ 
> or
> +		 * ZAPQ, then if it completes successfully, let's issue the ZAPQ.
> +		 */
> +		ret = apq_reset_check(q);
> +		if (ret)
> +			break;
> +		goto retry_zapq;
>  	case AP_RESPONSE_Q_NOT_AVAIL:
>  	case AP_RESPONSE_DECONFIGURED:
>  	case AP_RESPONSE_CHECKSTOPPED:
> @@ -1688,7 +1690,7 @@ static int vfio_ap_mdev_reset_queues(struct
> ap_queue_table *qtable)
>  	struct vfio_ap_queue *q;
> 
>  	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
> -		ret = vfio_ap_mdev_reset_queue(q, 1);
> +		ret = vfio_ap_mdev_reset_queue(q);
>  		/*
>  		 * Regardless whether a queue turns out to be busy, or
>  		 * is not operational, we need to continue resetting
> @@ -1931,7 +1933,7 @@ void vfio_ap_mdev_remove_queue(struct ap_device 
> *apdev)
>  		}
>  	}
> 
> -	vfio_ap_mdev_reset_queue(q, 1);
> +	vfio_ap_mdev_reset_queue(q);
>  	dev_set_drvdata(&apdev->device, NULL);
>  	kfree(q);
>  	release_update_locks_for_mdev(matrix_mdev);

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Re: [PATCH 3/7] s390/vfio_ap: use TAPQ to verify reset in progress completes
Posted by Anthony Krowiak 2 years, 9 months ago 
On 12/15/22 5:51 AM, Harald Freudenberger wrote:
> On 2022-12-13 16:44, Tony Krowiak wrote:
>> To eliminate the repeated calls to the PQAP(ZAPQ) function to verify 
>> that
>> a reset in progress completed successfully and ensure that error 
>> response
>> codes get appropriately logged, let's call the apq_reset_check() 
>> function
>> when the ZAPQ response code indicates that a reset that is already in
>> progress.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> ---
>>  drivers/s390/crypto/vfio_ap_ops.c | 24 +++++++++++++-----------
>>  1 file changed, 13 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
>> b/drivers/s390/crypto/vfio_ap_ops.c
>> index a5530a46cf31..5bf2d93ae8af 100644
>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>> @@ -33,7 +33,7 @@
>>  static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable);
>>  static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
>>  static const struct vfio_device_ops vfio_ap_matrix_dev_ops;
>> -static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, unsigned
>> int retry);
>> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q);
>>
>>  /**
>>   * get_update_locks_for_kvm: Acquire the locks required to 
>> dynamically update a
>> @@ -1632,8 +1632,7 @@ static int apq_reset_check(struct vfio_ap_queue 
>> *q)
>>      return ret;
>>  }
>>
>> -static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
>> -                    unsigned int retry)
>> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
>>  {
>>      struct ap_queue_status status;
>>      int ret;
>> @@ -1648,12 +1647,15 @@ static int vfio_ap_mdev_reset_queue(struct
>> vfio_ap_queue *q,
>>          ret = 0;
>>          break;
>>      case AP_RESPONSE_RESET_IN_PROGRESS:
>> -        if (retry--) {
>> -            msleep(20);
>> -            goto retry_zapq;
>> -        }
>> -        ret = -EBUSY;
>> -        break;
>> +        /*
>> +         * There is a reset issued by another process in progress. 
>> Let's wait
>> +         * for that to complete. Since we have no idea whether it 
>> was a RAPQ or
>> +         * ZAPQ, then if it completes successfully, let's issue the 
>> ZAPQ.
>> +         */
>> +        ret = apq_reset_check(q);
>> +        if (ret)
>> +            break;
>> +        goto retry_zapq;
>>      case AP_RESPONSE_Q_NOT_AVAIL:
>>      case AP_RESPONSE_DECONFIGURED:
>>      case AP_RESPONSE_CHECKSTOPPED:
>> @@ -1688,7 +1690,7 @@ static int vfio_ap_mdev_reset_queues(struct
>> ap_queue_table *qtable)
>>      struct vfio_ap_queue *q;
>>
>>      hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
>> -        ret = vfio_ap_mdev_reset_queue(q, 1);
>> +        ret = vfio_ap_mdev_reset_queue(q);
>>          /*
>>           * Regardless whether a queue turns out to be busy, or
>>           * is not operational, we need to continue resetting
>> @@ -1931,7 +1933,7 @@ void vfio_ap_mdev_remove_queue(struct ap_device 
>> *apdev)
>>          }
>>      }
>>
>> -    vfio_ap_mdev_reset_queue(q, 1);
>> +    vfio_ap_mdev_reset_queue(q);
>>      dev_set_drvdata(&apdev->device, NULL);
>>      kfree(q);
>>      release_update_locks_for_mdev(matrix_mdev);
>
> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>


Thanks for the review.

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.