On Thu, Sep 17, 2020 at 06:06:14PM +0200, Christian König wrote: > > > If it is already taking a page fault I'm not sure the extra function > > > call indirection is going to be a big deal. Having a uniform VMA > > > sounds saner than every driver custom rolling something. > > > > > > When I unwound a similar mess in RDMA all the custom VMA stuff in the > > > drivers turned out to be generally buggy, at least. > > > > > > Is vma->vm_file->private_data universally a dma_buf pointer at least? > > Nope. I think if you want this without some large scale rewrite of a > > lot of code we'd need a vmops->get_dmabuf or similar. Not pretty, but > > would get the job done. > > Yeah, agree that sounds like the simplest approach. I don't think that will fly, it is clearly only papering over a mess inside DRM/dma buf :\ Jason