On Tue, Jan 22, 2019 at 11:59:31AM -0800, Stefano Stabellini wrote: > > if (!virtio_has_iommu_quirk(vdev)) > > return true; > > > > @@ -260,7 +262,7 @@ static bool vring_use_dma_api(struct virtio_device *vdev) > > * the DMA API if we're a Xen guest, which at least allows > > * all of the sensible Xen configurations to work correctly. > > */ > > - if (xen_domain()) > > + if (xen_domain() && !dma_dev->dma_mem) > > return true; > > > > return false; > > I can see you spotted a real issue, but this is not the right fix. We > just need something a bit more flexible than xen_domain(): there are > many kinds of Xen domains on different architectures, we basically want > to enable this (return true from vring_use_dma_api) only when the xen > swiotlb is meant to be used. Does the appended patch fix the issue you > have? The problem generally is the other way around - if dma_dev->dma_mem is set the device decription in the device tree explicitly requires using this memory, so we must _always_ use the DMA API. The problem is just that that rproc driver absuses the DMA API in horrible ways. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization