On 19.05.21 13:58, Julian Wiedmann wrote: > 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? That's right - but really not a big issue. > > Same for patch 13.
