On Mon, Oct 20, 2025 at 4:42 PM Dmitry Osipenko <[email protected]> wrote: > > Add support for DRM native contexts to VirtIO-GPU. DRM context is enabled > using a new virtio-gpu-gl device option "drm_native_context=on". > > Unlike Virgl and Venus contexts that operate on application API level, > DRM native contexts work on a kernel UAPI level. This lower level results > in a lightweight context implementations that yield better performance. > > Reviewed-by: Akihiko Odaki <[email protected]> > Acked-by: Michael S. Tsirkin <[email protected]> > Tested-by: Alex Bennée <[email protected]> > Signed-off-by: Dmitry Osipenko <[email protected]> > --- > docs/system/devices/virtio-gpu.rst | 11 +++++++++++ > hw/display/virtio-gpu-gl.c | 2 ++ > hw/display/virtio-gpu-virgl.c | 28 ++++++++++++++++++++++++++++ > hw/display/virtio-gpu.c | 15 +++++++++++++++ > include/hw/virtio/virtio-gpu.h | 3 +++ > 5 files changed, 59 insertions(+) > > diff --git a/docs/system/devices/virtio-gpu.rst > b/docs/system/devices/virtio-gpu.rst > index b7eb0fc0e727..f20c60016376 100644 > --- a/docs/system/devices/virtio-gpu.rst > +++ b/docs/system/devices/virtio-gpu.rst > @@ -82,6 +82,17 @@ of virtio-gpu host memory window. This is typically > between 256M and 8G. > > .. _venus: https://gitlab.freedesktop.org/virgl/venus-protocol/ > > +DRM native context is supported since release of `virglrenderer`_ v1.0.0 > +using `drm`_ protocol. ``DRM`` virtio-gpu capability set ("capset") requires > +host blob support (``hostmem`` and ``blob`` fields) and should be enabled > +using ``drm_native_context`` field. The ``hostmem`` field specifies the size > +of virtio-gpu host memory window. This is typically between 256M and 8G. > + > +.. parsed-literal:: > + -device virtio-gpu-gl,hostmem=8G,blob=on,drm_native_context=on > + > +.. _drm: > https://gitlab.freedesktop.org/virgl/virglrenderer/-/tree/main/src/drm > + > virtio-gpu rutabaga > ------------------- > > diff --git a/hw/display/virtio-gpu-gl.c b/hw/display/virtio-gpu-gl.c > index 1468c6ed1467..b640900fc6f1 100644 > --- a/hw/display/virtio-gpu-gl.c > +++ b/hw/display/virtio-gpu-gl.c > @@ -159,6 +159,8 @@ static const Property virtio_gpu_gl_properties[] = { > VIRTIO_GPU_FLAG_STATS_ENABLED, false), > DEFINE_PROP_BIT("venus", VirtIOGPU, parent_obj.conf.flags, > VIRTIO_GPU_FLAG_VENUS_ENABLED, false), > + DEFINE_PROP_BIT("drm_native_context", VirtIOGPU, parent_obj.conf.flags, > + VIRTIO_GPU_FLAG_DRM_ENABLED, false), > }; > > static void virtio_gpu_gl_device_unrealize(DeviceState *qdev) > diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c > index 0320d6deca76..ccba1d8ee4f4 100644 > --- a/hw/display/virtio-gpu-virgl.c > +++ b/hw/display/virtio-gpu-virgl.c > @@ -1298,6 +1298,25 @@ int virtio_gpu_virgl_init(VirtIOGPU *g) > if (virtio_gpu_venus_enabled(g->parent_obj.conf)) { > flags |= VIRGL_RENDERER_VENUS | VIRGL_RENDERER_RENDER_SERVER; > } > + if (virtio_gpu_drm_enabled(g->parent_obj.conf)) { > + flags |= VIRGL_RENDERER_DRM; > + > + if (!(flags & VIRGL_RENDERER_ASYNC_FENCE_CB)) { > + /* > + * Virglrenderer skips enabling DRM context support without > + * enabled async-fence feature. VirtIO-GPU will initialize > + * successfully, but DRM context won't be available in guest. > + * > + * For vrend async-fencing can be enabled only if EGL display > + * is used. Vrend can't be disabled in QEMU, hence DRM implicitly > + * requires EGL too. > + * > + * Async-fence was bugged in virglrenderer versions <= 1.1.1. > + */ > + error_report("drm requires egl display and virglrenderer >= > 1.2.0"); > + return -EINVAL; > + } > + } > #endif > > ret = virgl_renderer_init(g, flags, &virtio_gpu_3d_cbs); > @@ -1361,5 +1380,14 @@ GArray *virtio_gpu_virgl_get_capsets(VirtIOGPU *g) > } > } > > + if (virtio_gpu_drm_enabled(g->parent_obj.conf)) { > + virgl_renderer_get_cap_set(VIRTIO_GPU_CAPSET_DRM, > + &capset_max_ver, > + &capset_max_size); > + if (capset_max_size) { > + virtio_gpu_virgl_add_capset(capset_ids, VIRTIO_GPU_CAPSET_DRM); > + } > + } > + > return capset_ids; > } > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c > index 3a555125be60..ad36ea6ee319 100644 > --- a/hw/display/virtio-gpu.c > +++ b/hw/display/virtio-gpu.c > @@ -1510,6 +1510,21 @@ void virtio_gpu_device_realize(DeviceState *qdev, > Error **errp) > #endif > } > > + if (virtio_gpu_drm_enabled(g->parent_obj.conf)) { > +#ifdef VIRGL_VERSION_MAJOR > + #if VIRGL_VERSION_MAJOR >= 1 > + if (!virtio_gpu_blob_enabled(g->parent_obj.conf) || > + !virtio_gpu_hostmem_enabled(g->parent_obj.conf)) { > + error_setg(errp, "drm requires enabled blob and hostmem > options"); > + return; > + } > + #else > + error_setg(errp, "old virglrenderer, drm unsupported"); > + return; > + #endif > +#endif > + } > + > if (!virtio_gpu_base_device_realize(qdev, > virtio_gpu_handle_ctrl_cb, > virtio_gpu_handle_cursor_cb, > diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h > index e15c16aa5945..a4963508a469 100644 > --- a/include/hw/virtio/virtio-gpu.h > +++ b/include/hw/virtio/virtio-gpu.h > @@ -100,6 +100,7 @@ enum virtio_gpu_base_conf_flags { > VIRTIO_GPU_FLAG_RUTABAGA_ENABLED, > VIRTIO_GPU_FLAG_VENUS_ENABLED, > VIRTIO_GPU_FLAG_RESOURCE_UUID_ENABLED, > + VIRTIO_GPU_FLAG_DRM_ENABLED, > }; > > #define virtio_gpu_virgl_enabled(_cfg) \ > @@ -122,6 +123,8 @@ enum virtio_gpu_base_conf_flags { > (_cfg.hostmem > 0) > #define virtio_gpu_venus_enabled(_cfg) \ > (_cfg.flags & (1 << VIRTIO_GPU_FLAG_VENUS_ENABLED)) > +#define virtio_gpu_drm_enabled(_cfg) \ > + (_cfg.flags & (1 << VIRTIO_GPU_FLAG_DRM_ENABLED)) > > struct virtio_gpu_base_conf { > uint32_t max_outputs; > -- > 2.51.0 >
Reviewed-by: Yiwei Zhang <[email protected]>
