From: Tony Krowiak <akrowiak@linux.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org
Cc: freude@linux.ibm.com, cohuck@redhat.com, mjrosato@linux.ibm.com,
pasic@linux.ibm.com, alex.williamson@redhat.com,
kwankhede@nvidia.com, fiuczy@linux.ibm.com
Subject: Re: [PATCH v8 02/16] s390/vfio-ap: use new AP bus interface to search for queue devices
Date: Wed, 17 Jun 2020 08:02:33 -0400 [thread overview]
Message-ID: <ba6e460c-36f5-051f-3549-9b826ae1d5ab@linux.ibm.com> (raw)
In-Reply-To: <93492fa3-31f1-a551-4b26-e46bc277e351@de.ibm.com>
On 6/16/20 11:45 AM, Christian Borntraeger wrote:
>
> On 05.06.20 23:39, Tony Krowiak wrote:
>> This patch refactor's the vfio_ap device driver to use the AP bus's
>> ap_get_qdev() function to retrieve the vfio_ap_queue struct containing
>> information about a queue that is bound to the vfio_ap device driver.
>> The bus's ap_get_qdev() function retrieves the queue device from a
>> hashtable keyed by APQN. This is much more efficient than looping over
>> the list of devices attached to the AP bus by several orders of
>> magnitude.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> ---
>> drivers/s390/crypto/vfio_ap_drv.c | 27 ++-------
>> drivers/s390/crypto/vfio_ap_ops.c | 82 +++++++++++++++------------
>> drivers/s390/crypto/vfio_ap_private.h | 8 ++-
>> 3 files changed, 58 insertions(+), 59 deletions(-)
>>
>> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
>> index be2520cc010b..59233cf7419d 100644
>> --- a/drivers/s390/crypto/vfio_ap_drv.c
>> +++ b/drivers/s390/crypto/vfio_ap_drv.c
>> @@ -51,15 +51,9 @@ MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
>> */
>> static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
>> {
>> - struct vfio_ap_queue *q;
>> -
>> - q = kzalloc(sizeof(*q), GFP_KERNEL);
>> - if (!q)
>> - return -ENOMEM;
>> - dev_set_drvdata(&apdev->device, q);
>> - q->apqn = to_ap_queue(&apdev->device)->qid;
>> - q->saved_isc = VFIO_AP_ISC_INVALID;
>> - return 0;
>> + struct ap_queue *queue = to_ap_queue(&apdev->device);
>> +
>> + return vfio_ap_mdev_probe_queue(queue);
>> }
> Here we did not hold a mutex in the old code
> [...]
>
>> +int vfio_ap_mdev_probe_queue(struct ap_queue *queue)
>> +{
>> + struct vfio_ap_queue *q;
>> +
>> + q = kzalloc(sizeof(*q), GFP_KERNEL);
>> + if (!q)
>> + return -ENOMEM;
>> +
>> + mutex_lock(&matrix_dev->lock);
>> + dev_set_drvdata(&queue->ap_dev.device, q);
>> + q->apqn = queue->qid;
>> + q->saved_isc = VFIO_AP_ISC_INVALID;
>> + mutex_unlock(&matrix_dev->lock);
>> +
> here we do. Why do we need the matrix_dev->lock here?
You are correct, we don't need it here; but, we will need it
in a subsequent patch where we introduce linking the
q to the matrix mdev to which it is assigned. Perhaps
the locking should be introduced in that patch.
>
next prev parent reply other threads:[~2020-06-17 12:04 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-05 21:39 [PATCH v8 00/16] s390/vfio-ap: dynamic configuration support Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 01/16] s390/ap: introduce new ap function ap_get_qdev() Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 02/16] s390/vfio-ap: use new AP bus interface to search for queue devices Tony Krowiak
2020-06-05 23:48 ` kernel test robot
2020-06-16 15:38 ` Christian Borntraeger
2020-06-16 15:45 ` Christian Borntraeger
2020-06-17 12:02 ` Tony Krowiak [this message]
2020-06-05 21:39 ` [PATCH v8 03/16] s390/vfio-ap: manage link between queue struct and matrix mdev Tony Krowiak
2020-06-16 17:50 ` Christian Borntraeger
2020-06-17 12:10 ` Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 04/16] s390/zcrypt: driver callback to indicate resource in use Tony Krowiak
2020-06-06 1:14 ` kernel test robot
2020-06-06 1:29 ` kernel test robot
2020-07-08 12:27 ` Christian Borntraeger
2020-07-08 14:04 ` Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 05/16] s390/vfio-ap: implement in-use callback for vfio_ap driver Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 06/16] s390/vfio-ap: introduce shadow APCB Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 07/16] s390/vfio-ap: sysfs attribute to display the guest's matrix Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 08/16] s390/vfio-ap: filter matrix for unavailable queue devices Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 09/16] s390/vfio_ap: add qlink from ap_matrix_mdev struct to vfio_ap_queue struct Tony Krowiak
2020-06-06 2:51 ` kernel test robot
2020-06-05 21:39 ` [PATCH v8 10/16] s390/vfio-ap: allow assignment of unavailable AP queues to mdev device Tony Krowiak
2020-06-05 21:39 ` [PATCH v8 11/16] s390/vfio-ap: allow configuration of matrix mdev in use by a KVM guest Tony Krowiak
2020-06-05 21:40 ` [PATCH v8 12/16] s390/vfio-ap: allow hot plug/unplug of AP resources using mdev device Tony Krowiak
2020-06-05 21:40 ` [PATCH v8 13/16] s390/zcrypt: Notify driver on config changed and scan complete callbacks Tony Krowiak
2020-06-05 21:40 ` [PATCH v8 14/16] s390/vfio-ap: handle host AP config change notification Tony Krowiak
2020-06-06 4:31 ` kernel test robot
2020-06-05 21:40 ` [PATCH v8 15/16] s390/vfio-ap: handle AP bus scan completed notification Tony Krowiak
2020-06-05 21:40 ` [PATCH v8 16/16] s390/vfio-ap: handle probe/remove not due to host AP config changes Tony Krowiak
2020-06-16 14:26 ` [PATCH v8 00/16] s390/vfio-ap: dynamic configuration support Tony Krowiak
2020-06-16 15:31 ` Christian Borntraeger
2020-06-17 12:21 ` Tony Krowiak
2020-06-22 14:03 ` Tony Krowiak
2020-06-29 15:11 ` Tony Krowiak
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