Hi, > > ... but after looking again I think we are all green here. Given that > > only self-import works we'll only see vram gem objects in the mmap code > > path, which should have everything set up correctly. Same goes for qxl. > > > > All other ttm drivers still use the old mmap code path, so all green > > there too I think. Also I somehow doubt dma-buf mmap vs. drm mmap ends > > up using different f_mapping, ttm code has a WARN_ON in ttm_bo_vm_open() > > which would fire should that be the case. > > > > Do imported dma-bufs hit the drm mmap code path in the first place? > > Wouldn't mmap be handled by the exporting driver? > > drm_gem_dmabuf_mmap -> obj->funcs->mmap -> ttm_bo_mmap_obj > > And I'm not seeing anyone adjusting vm_file->f_mapping anywhere here at all. [ some more code browsing ] Ok, I see. dma-bufs get their own file, their own anon inode and thereby their own address space. So that it used when mmaping the dma-buf. drm filehandle's get the shared address space instead, drm_open() sets it. So, yes, I see the problem. It's not new though, as far I can see the old dma-buf mmap code path doesn't adjust f_mapping anywhere either ... > Note to hit this you need userspace to > - handle2fd on a buffer to create a dma-buf fd > - call mmap directly on that dma-buf fd Hmm, seems for handle2fd I need a dummy gem_prime_get_sg_table function wired up even when not actually exporting/importing anything. So I think neither qxl nor any of the vram drivers allow to trigger that (and no other ttm driver uses the new ttm mmap code yet). So, $subject patch should not make things worse in ttm land. When hacking the bochs driver to have export callbacks (without supporting actual exports) handle2fd + mmap() callback works fine. Didn't verify yet I actually get the correct pages mapped. But maybe mmap() isn't the problem when the correct address space is important for unmap only. Is there a good test case? cheers, Gerd _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
