On 10.05.21 19:44, Tony Krowiak wrote: > Introduces a new driver callback to prevent a root user from unbinding > an AP queue from its device driver if the queue is in use. The callback > will be invoked whenever a change to the AP bus's sysfs apmask or aqmask > attributes would result in one or more AP queues being removed from its > driver. If the callback responds in the affirmative for any driver > queried, the change to the apmask or aqmask will be rejected with a device > busy error. > > For this patch, only non-default drivers will be queried. Currently, > there is only one non-default driver, the vfio_ap device driver. The > vfio_ap device driver facilitates pass-through of an AP queue to a > guest. The idea here is that a guest may be administered by a different > sysadmin than the host and we don't want AP resources to unexpectedly > disappear from a guest's AP configuration (i.e., adapters and domains > assigned to the matrix mdev). This will enforce the proper procedure for > removing AP resources intended for guest usage which is to > first unassign them from the matrix mdev, then unbind them from the > vfio_ap device driver. > > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx> > Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx> > --- > drivers/s390/crypto/ap_bus.c | 160 ++++++++++++++++++++++++++++++++--- > drivers/s390/crypto/ap_bus.h | 4 + > 2 files changed, 154 insertions(+), 10 deletions(-) > This doesn't touch the zcrypt drivers, so I _think_ the subject should rather be "s390/ap: driver callback to indicate resource in use". Harald? Same for patch 13.
