On Tue, 22 Dec 2020 20:20:13 -0500 Tony Krowiak <akrowiak@xxxxxxxxxxxxx> 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: > 1. Stashes the KVM pointer in the vfio_ap_mdev struct that holds the state > of the mediated device. > 2. Calls the kvm_get_kvm() function to increment its reference counter. > 3. Sets the function pointer to the function that handles interception of > the instruction that enables/disables interrupt processing. > 4. 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") > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx> > Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx> LGTM. Christian, you wanted to pick this yourself directly, or? I think we are good to go!