On Mon, Sep 07, 2020 at 03:53:02PM +0200, Daniel Vetter wrote: > On Mon, Sep 7, 2020 at 1:24 PM Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > > > > Add drm_device argument to drm_prime_pages_to_sg(), so we can > > call dma_max_mapping_size() to figure the segment size limit > > and call into __sg_alloc_table_from_pages() with the correct > > limit. > > > > This fixes virtio-gpu with sev. Possibly it'll fix other bugs > > too given that drm seems to totaly ignore segment size limits > > so far ... > > > > v2: place max_segment in drm driver not gem object. > > v3: move max_segment next to the other gem fields. > > v4: just use dma_max_mapping_size(). > > > > Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> > > Uh, are you sure this works in all cases for virtio? Sure, I've tested it ;) > The comments I've found suggest very much not ... Or is that all very > old stuff only that no one cares about anymore? I think these days it is possible to override dma_ops per device, which in turn allows virtio to deal with the quirks without the rest of the kernel knowing about these details. I also think virtio-gpu can drop the virtio_has_dma_quirk() checks, just use the dma api path unconditionally and depend on virtio core having setup dma_ops in a way that it JustWorks[tm]. I'll look into that next. take care, Gerd _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
