virglrenderer recently added virgl_renderer_resource_get_info_ext as a new api, which gets resource information, including dmabuf modifiers. https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/1024
We have to support dmabuf modifiers since the driver may choose to allocate buffers with these modifiers to improve performance, and importing buffers without modifiers information may result in completely broken rendering. Currently trying to use vhost-user-gpu for rendering backend and using the qemu dbus ui as a ui backend results in a broken framebuffer with Intel GPUs as the buffer is allocated with a modifier. With this patchset, that is fixed. It is tricky to support since it requires to keep compatibility at the same time with: (1) build against older virglrenderer which do not provide virgl_renderer_resource_get_info_ext; (2) runtime between frontend (qemu) and backend (vhost-user-gpu) due to increased size and a new field in the VHOST_USER_GPU_DMABUF_SCANOUT message. I tried to reach a compromise here by not defining a completely new message and duplicate VHOST_USER_GPU_DMABUF_SCANOUT but it still feels like a bit of a hack, so I appreciate feedback if there is a better way (or naming) to handle it. Erico Nunes (3): docs: vhost-user-gpu: add protocol changes for dmabuf modifiers contrib/vhost-user-gpu: add support for sending dmabuf modifiers vhost-user-gpu: support dmabuf modifiers contrib/vhost-user-gpu/vhost-user-gpu.c | 5 ++- contrib/vhost-user-gpu/virgl.c | 51 +++++++++++++++++++++++-- contrib/vhost-user-gpu/vugpu.h | 9 +++++ docs/interop/vhost-user-gpu.rst | 26 ++++++++++++- hw/display/vhost-user-gpu.c | 17 ++++++++- 5 files changed, 102 insertions(+), 6 deletions(-) -- 2.40.1
