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| author | Rob Clark <robdclark@chromium.org> | 2023-03-03 00:35:06 +0100 |
|---|---|---|
| committer | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2023-03-03 21:29:54 +0100 |
| commit | 72122c69d71784e390527819754ea456421c4501 (patch) | |
| tree | 329e85fe325c48e0add6c7277966f6543d406bf0 /drivers/gpu/drm/virtio/virtgpu_kms.c | |
| parent | dma-buf: Include missing parentheses to documentation (diff) | |
| download | linux-72122c69d71784e390527819754ea456421c4501.tar.xz linux-72122c69d71784e390527819754ea456421c4501.zip | |
drm/virtio: Add option to disable KMS support
Add a build option to disable modesetting support. This is useful in
cases where the guest only needs to use the GPU in a headless mode, or
(such as in the CrOS usage) window surfaces are proxied to a host
compositor.
As the modesetting ioctls are a big surface area for potential security
bugs to be found (it's happened in the past, we should assume it will
again in the future), it makes sense to have a build option to disable
those ioctls in cases where they serve no legitimate purpose.
v2: Use more if (IS_ENABLED(...))
v3: Also permit the host to advertise no scanouts
v4: Spiff out commit msg
v5: Make num_scanouts==0 and DRM_VIRTIO_GPU_KMS=n behave the same
v6: Drop conditionally building virtgpu_display.c and early-out of
it's init/fini fxns instead
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302233506.3146290-1-robdclark@gmail.com
Diffstat (limited to 'drivers/gpu/drm/virtio/virtgpu_kms.c')
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_kms.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c index 27b7f14dae89..02e5c18c2c75 100644 --- a/drivers/gpu/drm/virtio/virtgpu_kms.c +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c @@ -223,12 +223,15 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev) num_scanouts, &num_scanouts); vgdev->num_scanouts = min_t(uint32_t, num_scanouts, VIRTIO_GPU_MAX_SCANOUTS); - if (!vgdev->num_scanouts) { - DRM_ERROR("num_scanouts is zero\n"); - ret = -EINVAL; - goto err_scanouts; + + if (IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS) || !vgdev->num_scanouts) { + DRM_INFO("KMS disabled\n"); + vgdev->num_scanouts = 0; + vgdev->has_edid = false; + dev->driver_features &= ~(DRIVER_MODESET | DRIVER_ATOMIC); + } else { + DRM_INFO("number of scanouts: %d\n", num_scanouts); } - DRM_INFO("number of scanouts: %d\n", num_scanouts); virtio_cread_le(vgdev->vdev, struct virtio_gpu_config, num_capsets, &num_capsets); @@ -246,10 +249,12 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev) virtio_gpu_get_capsets(vgdev, num_capsets); if (vgdev->has_edid) virtio_gpu_cmd_get_edids(vgdev); - virtio_gpu_cmd_get_display_info(vgdev); - virtio_gpu_notify(vgdev); - wait_event_timeout(vgdev->resp_wq, !vgdev->display_info_pending, - 5 * HZ); + if (vgdev->num_scanouts) { + virtio_gpu_cmd_get_display_info(vgdev); + virtio_gpu_notify(vgdev); + wait_event_timeout(vgdev->resp_wq, !vgdev->display_info_pending, + 5 * HZ); + } return 0; err_scanouts: |