On 5/19/21 7:58 AM, 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?
Same for patch 13.
Kind of a nit, but I can make the change.
