On Wed, Jan 9, 2019 at 12:36 PM Daniel Vetter <dan...@ffwll.ch> wrote: > > On Wed, Jan 9, 2019 at 3:54 PM Gerd Hoffmann <kra...@redhat.com> wrote: > > > > On Wed, Jan 09, 2019 at 11:10:44AM +0100, Daniel Vetter wrote: > > > On Tue, Jan 08, 2019 at 12:25:19PM +0100, Gerd Hoffmann wrote: > > > > The buffer object must be reserved before calling > > > > ttm_bo_validate for pinning/unpinning. > > > > > > > > Signed-off-by: Gerd Hoffmann <kra...@redhat.com> > > > > > > Seems a bit a bisect fumble in your series here: legacy kms code reserved > > > the ttm bo before calling boch_bo_pin/unpin, your atomic code doesn't. I > > > think pushing this into bochs_bo_pin/unpin makes sense for atomic, but to > > > avoid bisect fail I think you need to have these temporarily in your > > > cleanup/prepare_plane functions too. > > > > I think I've sorted that. Have some other changes too, will probably > > send v3 tomorrow. > > > > > Looked through the entire series, this here is the only issue I think > > > should be fixed before merging (making atomic_enable optional can be done > > > as a follow-up if you feel like it). With that addressed on the series: > > > > > > Acked-by: Daniel Vetter <daniel.vet...@ffwll.ch> > > > > Thanks. > > > > While being at it: I'm also looking at dma-buf export and import > > support for the qemu drivers. > > > > Right now both qxl and virtio have gem_prime_get_sg_table and > > gem_prime_import_sg_table handlers which throw a WARN_ONCE() and return > > an error. > > > > If I understand things correctly it is valid to set all import/export > > callbacks (prime_handle_to_fd, prime_fd_to_handle, > > gem_prime_get_sg_table, gem_prime_import_sg_table) to NULL when not > > supporting dma-buf import/export and still advertise DRIVER_PRIME to > > indicate the other prime callbacks are supported (so generic fbdev > > emulation can use gem_prime_vmap etc). Is that correct? > > I'm not sure how much that's a good idea ... Never thought about it > tbh. All the fbdev/dma-buf stuff has plenty of hacks and > inconsistencies still, so I guess we can't make it much worse really. > > > On exporting: > > > > TTM_PL_TT should be easy, just pin the buffer, grab the pages list and > > feed that into drm_prime_pages_to_sg. Didn't try yet though. Is that > > approach correct? > > > > Is it possible to export TTM_PL_VRAM objects (with backing storage being > > a pci memory bar)? If so, how? > > Not really in general. amdgpu upcasts to amdgpu_bo (if it's amgpu BO) > and then knows the internals so it can do a proper pci peer2peer > mapping. Or at least there's been lots of patches floating around to > make that happen.
Here's Christian's WIP stuff for adding device memory support to dma-buf: https://cgit.freedesktop.org/~deathsimple/linux/log/?h=p2p Alex > > I think other drivers migrate the bo out of VRAM. > > > On importing: > > > > Importing into TTM_PL_TT object looks easy again, at least when the > > object is actually stored in RAM. What if not? > > They are all supposed to be stored in RAM. Note that all current ttm > importers totally break the abstraction, by taking the sg list, > throwing the dma mapping away and assuming there's a struct page > backing it. Would be good if we could stop spreading that abuse - the > dma-buf interfaces have been modelled after the ttm bo interfaces, so > shouldn't be too hard to wire this up correctly. > > > Importing into TTM_PL_VRAM: Impossible I think, without copying over > > the data. Should that be done? If so, how? Or is it better to just > > not support import then? > > Hm, since you ask about TTM concepts and not what this means in terms > of dma-buf: As long as you upcast to the ttm_bo you can do whatever > you want to really. But with plain dma-buf this doesn't work right now > (least because ttm assumes it gets system RAM on import, in theory you > could put the peer2peer dma mapping into the sg list and it should > work). > -Daniel > > > > > thanks, > > Gerd > > > > _______________________________________________ > > dri-devel mailing list > > dri-de...@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch > _______________________________________________ > dri-devel mailing list > dri-de...@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
