On Wed, Jun 09, 2021 at 06:46:34PM -0400, Tony Krowiak wrote: > The function pointer to the interception handler for the PQAP instruction > can get changed during the interception process. Let's add a > semaphore to struct kvm_s390_crypto to control read/write access to the > function pointer contained therein. > > The semaphore must be locked for write access by the vfio_ap device driver > when notified that the KVM pointer has been set or cleared. It must be > locked for read access by the interception framework when the PQAP > instruction is intercepted. > > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > --- > arch/s390/include/asm/kvm_host.h | 6 +++--- > arch/s390/kvm/kvm-s390.c | 1 + > arch/s390/kvm/priv.c | 6 +++--- > drivers/s390/crypto/vfio_ap_ops.c | 14 ++++++++++---- > drivers/s390/crypto/vfio_ap_private.h | 2 +- > 5 files changed, 18 insertions(+), 11 deletions(-) This is alot better than the try_module_get! Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Jason
