On Mon, Jun 28, 2021 at 02:20:55PM -0400, Tony Krowiak wrote: > > > On 6/28/21 1:34 PM, Jason Gunthorpe wrote: > > On Fri, Jun 25, 2021 at 06:07:58PM -0400, Tony Krowiak wrote: > > > static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev) > > > { > > > + mutex_lock(&matrix_dev->lock); > > > + if ((matrix_mdev->kvm) && (matrix_mdev->kvm->arch.crypto.crycbd)) { > > > mutex_unlock(&matrix_dev->lock); > > > + down_write(&matrix_mdev->kvm->arch.crypto.pqap_hook_rwsem); > > > + matrix_mdev->kvm->arch.crypto.pqap_hook = NULL; > > > + up_write(&matrix_mdev->kvm->arch.crypto.pqap_hook_rwsem); > > > + kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > > > mutex_lock(&matrix_dev->lock); > > > vfio_ap_mdev_reset_queues(matrix_mdev->mdev); > > > kvm_put_kvm(matrix_mdev->kvm); > > > matrix_mdev->kvm = NULL; > > > + mutex_unlock(&matrix_dev->lock); > > > } > > Doesn't a flow exit the function with matrix_dev->lock held he > > How can that happen? What flow? When the if isn't taken > > Write it with 'success oriented flow' > > I'm not sure what you mean, can you clarify this statement? Basically, don't write the bulk of the function under an if statement mutex_lock(&matrix_dev->lock); if (!matrix_mdev->kvm || !matrix_mdev->kvm->arch.crypto.crycbd) { mutex_unlock(&matrix_dev->lock); return; } Jason