On 8/25/20 6:13 AM, Cornelia Huck wrote:
On Fri, 21 Aug 2020 15:56:02 -0400
Tony Krowiak<akrowiak@xxxxxxxxxxxxx> wrote:
This patch refactor's the vfio_ap device driver to use the AP bus's
s/refactor's/refactors/
Of course, what was I thinking?:)
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@xxxxxxxxxxxxx>
Reported-by: kernel test robot<lkp@xxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_drv.c | 27 ++-------
drivers/s390/crypto/vfio_ap_ops.c | 86 +++++++++++++++------------
drivers/s390/crypto/vfio_ap_private.h | 8 ++-
3 files changed, 59 insertions(+), 62 deletions(-)
(...)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e0bde8518745..ad3925f04f61 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -26,43 +26,26 @@
static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
-static int match_apqn(struct device *dev, const void *data)
-{
- struct vfio_ap_queue *q = dev_get_drvdata(dev);
-
- return (q->apqn == *(int *)(data)) ? 1 : 0;
-}
-
/**
- * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
- * @matrix_mdev: the associated mediated matrix
+ * vfio_ap_get_queue: Retrieve a queue with a specific APQN.
* @apqn: The queue APQN
*
- * Retrieve a queue with a specific APQN from the list of the
- * devices of the vfio_ap_drv.
- * Verify that the APID and the APQI are set in the matrix.
+ * Retrieve a queue with a specific APQN from the AP queue devices attached to
+ * the AP bus.
*
- * Returns the pointer to the associated vfio_ap_queue
+ * Returns the pointer to the vfio_ap_queue with the specified APQN, or NULL.
*/
-static struct vfio_ap_queue *vfio_ap_get_queue(
- struct ap_matrix_mdev *matrix_mdev,
- int apqn)
+static struct vfio_ap_queue *vfio_ap_get_queue(unsigned long apqn)
{
+ struct ap_queue *queue;
struct vfio_ap_queue *q;
- struct device *dev;
- if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
- return NULL;
- if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
I think you should add some explanation to the patch description why
testing the matrix bitmasks is not needed anymore.
As a result of this comment, I took a closer look at the code to
determine the reason for eliminating the matrix_mdev
parameter. The reason is because the code below (i.e., find the device
and get the driver data) was also repeated in the vfio_ap_irq_disable_apqn()
function, so I replaced it with a call to the function above; however, the
vfio_ap_irq_disable_apqn() function does not have a reference to the
matrix_mdev, so I eliminated the matrix_mdev parameter. Note that the
vfio_ap_irq_disable_apqn() is called for each APQN assigned to a matrix
mdev, so there is no need to test the bitmasks there.
The other place from which the function above is called is
the handle_pqap() function which does have a reference to the
matrix_mdev. In order to ensure the integrity of the instruction
being intercepted - i.e., PQAP(AQIC) enable/disable IRQ for aN
AP queue - the testing of the matrix bitmasks probably ought to
be performed, so it will be done there instead of in the
vfio_ap_get_queue() function above.
+ queue = ap_get_qdev(apqn);
+ if (!queue)
return NULL;
- dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
- &apqn, match_apqn);
- if (!dev)
- return NULL;
- q = dev_get_drvdata(dev);
- q->matrix_mdev = matrix_mdev;
- put_device(dev);
+ q = dev_get_drvdata(&queue->ap_dev.device);
+ put_device(&queue->ap_dev.device);
return q;
}
(...)
