On Fri, 8 Mar 2019 16:07:54 -0600 Parav Pandit <parav@xxxxxxxxxxxx> wrote: > Inherit dma mask of parent device in child mdev devices, so that > protocol stack can use right dma mask while doing dma mappings. > > Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx> > --- > drivers/vfio/mdev/mdev_core.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > index 0212f0e..9b8bdc9 100644 > --- a/drivers/vfio/mdev/mdev_core.c > +++ b/drivers/vfio/mdev/mdev_core.c > @@ -315,6 +315,10 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid) > mdev->dev.parent = dev; > mdev->dev.bus = &mdev_bus_type; > mdev->dev.release = mdev_device_release; > + mdev->dev.dma_mask = dev->dma_mask; > + mdev->dev.dma_parms = dev->dma_parms; > + mdev->dev.coherent_dma_mask = dev->coherent_dma_mask; > + > dev_set_name(&mdev->dev, "%pUl", uuid.b); > > ret = device_register(&mdev->dev); This seems like a rather large assumption and none of the existing mdev drivers even make use of DMA ops. Why shouldn't this be done in mdev_parent_ops.create? Thanks, Alex