On Mon, 14 Dec 2020 11:56:17 -0500 Tony Krowiak akrowiak@linux.ibm.com wrote:
The vfio_ap device driver registers a group notifier with VFIO when the file descriptor for a VFIO mediated device for a KVM guest is opened to receive notification that the KVM pointer is set (VFIO_GROUP_NOTIFY_SET_KVM event). When the KVM pointer is set, the vfio_ap driver takes the following actions:
- Stashes the KVM pointer in the vfio_ap_mdev struct that holds the state of the mediated device.
- Calls the kvm_get_kvm() function to increment its reference counter.
- Sets the function pointer to the function that handles interception of the instruction that enables/disables interrupt processing.
- Sets the masks in the KVM guest's CRYCB to pass AP resources through to the guest.
In order to avoid memory leaks, when the notifier is called to receive notification that the KVM pointer has been set to NULL, the vfio_ap device driver should reverse the actions taken when the KVM pointer was set.
Fixes: 258287c994de ("s390: vfio-ap: implement mediated device open callback") Signed-off-by: Tony Krowiak akrowiak@linux.ibm.com
drivers/s390/crypto/vfio_ap_ops.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-)
Reviewed-by: Cornelia Huck cohuck@redhat.com