On 4/16/20 7:18 AM, Cornelia Huck wrote:
On Tue, 7 Apr 2020 15:20:04 -0400 Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:Let's implement the callback to indicate when an APQN is in use by the vfio_ap device driver. The callback is invoked whenever a change to the apmask or aqmask would result in one or more queue devices being removed from the driver. The vfio_ap device driver will indicate a resource is in use if the APQN of any of the queue devices to be removed are assigned to any of the matrix mdevs under the driver's control. Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> --- drivers/s390/crypto/vfio_ap_drv.c | 1 + drivers/s390/crypto/vfio_ap_ops.c | 47 +++++++++++++++++---------- drivers/s390/crypto/vfio_ap_private.h | 2 ++ 3 files changed, 33 insertions(+), 17 deletions(-) @@ -1369,3 +1371,14 @@ void vfio_ap_mdev_remove_queue(struct ap_queue *queue) kfree(q); mutex_unlock(&matrix_dev->lock); } + +bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm) +{ + bool in_use; + + mutex_lock(&matrix_dev->lock); + in_use = vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm) ? true : false;Maybe in_use = !!vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm); ?
To be honest, I find the !! expression very confusing. Every time I see it, I have
to spend time thinking about what the result of !! is going to be. I think the statement should be left as-is because it more clearly expresses the intent.
+ mutex_unlock(&matrix_dev->lock); + + return in_use; +}
