kernel/linux.git/drivers/gpu/drm/virtio/virtgpu_prime.c, branch v6.18.22

Revert "drm/virtio: Use dma_buf from GEM object instance"

2025-07-17T10:26:19+00:00

This reverts commit 415cb45895f43015515473fbc40563ca5eec9a7c. The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref. Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated. Hence, this revert to going back to using .import_attach->dmabuf. Signed-off-by: Thomas Zimmermann Reviewed-by: Simona Vetter Acked-by: Christian König Acked-by: Zack Rusin Link: https://lore.kernel.org/r/20250715155934.150656-3-tzimmermann@suse.de

drm/virtio: Use dma_buf from GEM object instance

2025-04-16T07:05:03+00:00

Avoid dereferencing struct drm_gem_object.import_attach for the imported dma-buf. The dma_buf field in the GEM object instance refers to the same buffer. Prepares to make import_attach optional. Signed-off-by: Thomas Zimmermann Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko Link: https://lore.kernel.org/r/20250414131507.566072-3-tzimmermann@suse.de

drm/virtio: Test for imported buffers with drm_gem_is_imported()

2025-04-16T07:05:03+00:00

Instead of testing import_attach for imported GEM buffers, invoke drm_gem_is_imported() to do the test. The helper tests the dma_buf itself while import_attach is just an artifact of the import. Prepares to make import_attach optional. Signed-off-by: Thomas Zimmermann Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko Link: https://lore.kernel.org/r/20250414131507.566072-2-tzimmermann@suse.de

Merge tag 'drm-misc-next-2025-04-09' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

2025-04-14T05:29:49+00:00

drm-misc-next for v6.16-rc1: UAPI Changes: - Add ASAHI uapi header! - Add apple fourcc modifiers. - Add capset virtio definitions to UAPI. - Extend EXPORT_SYNC_FILE for timeline syncobjs. Cross-subsystem Changes: - Adjust DMA-BUF sg handling to not cache map on attach. - Update drm/ci, hlcdc, virtio, maintainers. - Update fbdev todo. - Allow setting dma-device for dma-buf import. - Export efi_mem_desc_lookup to make efidrm build as a module. Core Changes: - Update drm scheduler docs. - Use the correct resv object in TTM delayed destroy. - Fix compiler warning with panic qr code, and other small fixes. - drm/ci updates. - Add debugfs file for listing all bridges. - Small fixes to drm/client, ttm tests. - Add documentation to display/hdmi. - Add kunit tests for bridges. - Dont fail managed device probing if connector polling fails. - Create Kconfig.debug for drm core. - Add tests for the drm scheduler. - Add and use new access helpers for DPCPD. - Add generic and optimized conversions for format-helper. - Begin refcounting panel for improving lifetime handling. - Unify simpledrm and ofdrm sysfb, and add extra features. - Split hdmi audio in bridge to make DP audio work. Driver Changes: - Convert drivers to use devm_platform_ioremap_resource(). - Assorted small fixes to imx/legacy-bridg, gma500, pl111, nouveau, vc4, vmwgfx, ast, mxsfb, xlnx, accel/qaic, v3d, bridge/imx8qxp-ldb, ofdrm, bridge/fsl-ldb, udl, bridge/ti-sn65dsi86, bridge/anx7625, cirrus-qemu, bridge/cdns-dsi, panel/sharp, panel/himax, bridge/sil902x, renesas, imagination, various panels. - Allow attaching more display to vkms. - Add Powertip PH128800T004-ZZA01 panel. - Add rotation quirk for ZOTAC panel. - Convert bridge/tc358775 to atomic. - Remove deprecated panel calls from synaptics, novatek, samsung panels. - Refactor shmem helper page pinning and accel drivers using it. - Add dmabuf support to accel/amdxdna. - Use 4k page table format for panfrost/mediatek. - Add common powerup/down dp link helper and use it. - Assorted compiler warning fixes. - Support dma-buf import for renesas Signed-off-by: Dave Airlie # Conflicts: # include/drm/drm_kunit_helpers.h From: Maarten Lankhorst Link: https://lore.kernel.org/r/e147ff95-697b-4067-9e2e-7cbd424e162a@linux.intel.com

Merge drm/drm-fixes into drm-misc-fixes

2025-04-08T08:15:47+00:00

Backmerging to get updates from v6.15-rc1. Signed-off-by: Thomas Zimmermann

drm/virtio: Fix flickering issue seen with imported dmabufs

2025-03-26T20:59:41+00:00

We need to save the reservation object pointer associated with the imported dmabuf in the newly created GEM object to allow drm_gem_plane_helper_prepare_fb() to extract the exclusive fence from it and attach it to the plane state during prepare phase. This is needed to ensure that drm_atomic_helper_wait_for_fences() correctly waits for the relevant fences (move, etc) associated with the reservation object, thereby implementing proper synchronization. Otherwise, artifacts or slight flickering can be seen when apps are dragged across the screen when running Gnome (Wayland). This problem is mostly seen with dGPUs in the case where the FBs are allocated in VRAM but need to be migrated to System RAM as they are shared with virtio-gpu. Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as guest blobs") Cc: Gerd Hoffmann Cc: Dmitry Osipenko Cc: Gurchetan Singh Cc: Chia-I Wu Signed-off-by: Vivek Kasireddy Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko [dmitry.osipenko@collabora.com: Moved assignment before object_init()] Link: https://patchwork.freedesktop.org/patch/msgid/20250325201021.1315080-1-vivek.kasireddy@intel.com

dma-buf: drop caching of sg_tables

2025-03-06T14:21:36+00:00

That was purely for the transition from static to dynamic dma-buf handling and can be removed again now. Signed-off-by: Christian König Reviewed-by: Simona Vetter Reviewed-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/20250211163109.12200-5-christian.koenig@amd.com

drm/virtio: Fix UAF in virtgpu_dma_buf_free_obj()

2025-01-19T12:12:28+00:00

Fix the following issues identified by Smatch static checker: - The call to dma_buf_put(attach->dmabuf) after dma_buf_detach() leads to a UAF bug as dma_buf_detach() frees the attach object. Fix this by extracting the dmabuf object from attach and using that in the call to dma_buf_put(). - The resv object is extracted from attach before checking to see if attach is valid (that is !NULL) or not. Although, attach would very likely be valid, fix this by making sure that the resv object is used only after ensuring that attach is valid. Fixes: 2885e575abc7 ("drm/virtio: Add helpers to initialize and free the imported object") Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as guest blobs") Cc: Gerd Hoffmann Cc: Dmitry Osipenko Cc: Gurchetan Singh Cc: Chia-I Wu Reported-by: Dan Carpenter Signed-off-by: Vivek Kasireddy Link: https://patchwork.freedesktop.org/patch/msgid/20241212055421.775759-1-vivek.kasireddy@intel.com Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko [dmitry.osipenko@collabora.com: Edited commit title]

drm/virtio: Factor out common dmabuf unmapping code

2025-01-09T13:53:24+00:00

Move out dmabuf detachment and unmapping into separate function. This removes duplicated code and there is no need to check the GEM's kref now, since both bo->attached and bo->sgt are unset under held reservation lock. Signed-off-by: Dmitry Osipenko Acked-by: Vivek Kasireddy Link: https://patchwork.freedesktop.org/patch/msgid/20241202053955.2451321-1-dmitry.osipenko@collabora.com

drm/virtio: Set missing bo->attached flag

2025-01-09T13:53:19+00:00

VirtIO-GPU driver now supports detachment of shmem BOs from host, but doing it only for imported dma-bufs. Mark all shmem BOs as attached, not just dma-bufs. This is a minor correction since detachment of a non-dmabuf BOs not supported today. Signed-off-by: Dmitry Osipenko Acked-by: Vivek Kasireddy Link: https://patchwork.freedesktop.org/patch/msgid/20241129155357.2265357-1-dmitry.osipenko@collabora.com