On Wed, Jun 17, 2020 at 11:29:46AM +0800, Jason Wang wrote: > In order to let userspace work correctly, get_iova_range() is a must > for the device that has its own DMA translation logic.
I guess you mean for a device. However in absence of ths op, I don't see what is wrong with just assuming device can access any address. > > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > drivers/vdpa/vdpa.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index de211ef3738c..ab7af978ef70 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -82,6 +82,10 @@ struct vdpa_device *__vdpa_alloc_device(struct device > *parent, > if (!!config->dma_map != !!config->dma_unmap) > goto err; > > + if ((config->dma_map || config->set_map) && > + !config->get_iova_range) > + goto err; > + > err = -ENOMEM; > vdev = kzalloc(size, GFP_KERNEL); > if (!vdev) What about devices using an IOMMU for translation? IOMMUs generally have a limited IOVA range too, right? > -- > 2.20.1
