Daniel Vetter
2022-Aug-10 16:40 UTC
[PATCH v2 1/8] drm: Disable the cursor plane on atomic contexts with virtualized drivers
On Mon, Jul 11, 2022 at 11:32:39PM -0400, Zack Rusin wrote:> From: Zack Rusin <zackr at vmware.com> > > Cursor planes on virtualized drivers have special meaning and require > that the clients handle them in specific ways, e.g. the cursor plane > should react to the mouse movement the way a mouse cursor would be > expected to and the client is required to set hotspot properties on it > in order for the mouse events to be routed correctly. > > This breaks the contract as specified by the "universal planes". Fix it > by disabling the cursor planes on virtualized drivers while adding > a foundation on top of which it's possible to special case mouse cursor > planes for clients that want it. > > Disabling the cursor planes makes some kms compositors which were broken, > e.g. Weston, fallback to software cursor which works fine or at least > better than currently while having no effect on others, e.g. gnome-shell > or kwin, which put virtualized drivers on a deny-list when running in > atomic context to make them fallback to legacy kms and avoid this issue. > > Signed-off-by: Zack Rusin <zackr at vmware.com> > Fixes: 681e7ec73044 ("drm: Allow userspace to ask for universal plane list (v2)") > Cc: <stable at vger.kernel.org> # v5.4+ > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> > Cc: Maxime Ripard <mripard at kernel.org> > Cc: Thomas Zimmermann <tzimmermann at suse.de> > Cc: David Airlie <airlied at linux.ie> > Cc: Daniel Vetter <daniel at ffwll.ch> > Cc: Dave Airlie <airlied at redhat.com> > Cc: Gerd Hoffmann <kraxel at redhat.com> > Cc: Hans de Goede <hdegoede at redhat.com> > Cc: Gurchetan Singh <gurchetansingh at chromium.org> > Cc: Chia-I Wu <olvaffe at gmail.com> > Cc: dri-devel at lists.freedesktop.org > Cc: virtualization at lists.linux-foundation.org > Cc: spice-devel at lists.freedesktop.org > --- > drivers/gpu/drm/drm_plane.c | 11 +++++++++++ > drivers/gpu/drm/qxl/qxl_drv.c | 2 +- > drivers/gpu/drm/vboxvideo/vbox_drv.c | 2 +- > drivers/gpu/drm/virtio/virtgpu_drv.c | 3 ++- > drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 +- > include/drm/drm_drv.h | 10 ++++++++++ > include/drm/drm_file.h | 12 ++++++++++++ > 7 files changed, 38 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c > index 726f2f163c26..e1e2a65c7119 100644 > --- a/drivers/gpu/drm/drm_plane.c > +++ b/drivers/gpu/drm/drm_plane.c > @@ -667,6 +667,17 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data, > !file_priv->universal_planes) > continue; > > + /* > + * Unless userspace supports virtual cursor plane > + * then if we're running on virtual driver do not > + * advertise cursor planes because they'll be broken > + */ > + if (plane->type == DRM_PLANE_TYPE_CURSOR && > + drm_core_check_feature(dev, DRIVER_VIRTUAL) && > + file_priv->atomic && > + !file_priv->supports_virtual_cursor_plane) > + continue; > + > if (drm_lease_held(file_priv, plane->base.id)) { > if (count < plane_resp->count_planes && > put_user(plane->base.id, plane_ptr + count)) > diff --git a/drivers/gpu/drm/qxl/qxl_drv.c b/drivers/gpu/drm/qxl/qxl_drv.c > index 1cb6f0c224bb..0e4212e05caa 100644 > --- a/drivers/gpu/drm/qxl/qxl_drv.c > +++ b/drivers/gpu/drm/qxl/qxl_drv.c > @@ -281,7 +281,7 @@ static const struct drm_ioctl_desc qxl_ioctls[] = { > }; > > static struct drm_driver qxl_driver = { > - .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, > + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_VIRTUAL, > > .dumb_create = qxl_mode_dumb_create, > .dumb_map_offset = drm_gem_ttm_dumb_map_offset, > diff --git a/drivers/gpu/drm/vboxvideo/vbox_drv.c b/drivers/gpu/drm/vboxvideo/vbox_drv.c > index f4f2bd79a7cb..84e75bcc3384 100644 > --- a/drivers/gpu/drm/vboxvideo/vbox_drv.c > +++ b/drivers/gpu/drm/vboxvideo/vbox_drv.c > @@ -176,7 +176,7 @@ DEFINE_DRM_GEM_FOPS(vbox_fops); > > static const struct drm_driver driver = { > .driver_features > - DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC, > + DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC | DRIVER_VIRTUAL, > > .lastclose = drm_fb_helper_lastclose, > > diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c > index 5f25a8d15464..3c5bb006159a 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_drv.c > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c > @@ -198,7 +198,8 @@ MODULE_AUTHOR("Alon Levy"); > DEFINE_DRM_GEM_FOPS(virtio_gpu_driver_fops); > > static const struct drm_driver driver = { > - .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_RENDER | DRIVER_ATOMIC, > + .driver_features > + DRIVER_MODESET | DRIVER_GEM | DRIVER_RENDER | DRIVER_ATOMIC | DRIVER_VIRTUAL, > .open = virtio_gpu_driver_open, > .postclose = virtio_gpu_driver_postclose, > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > index 01a5b47e95f9..712f6ad0b014 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > @@ -1581,7 +1581,7 @@ static const struct file_operations vmwgfx_driver_fops = { > > static const struct drm_driver driver = { > .driver_features > - DRIVER_MODESET | DRIVER_RENDER | DRIVER_ATOMIC | DRIVER_GEM, > + DRIVER_MODESET | DRIVER_RENDER | DRIVER_ATOMIC | DRIVER_GEM | DRIVER_VIRTUAL, > .ioctls = vmw_ioctls, > .num_ioctls = ARRAY_SIZE(vmw_ioctls), > .master_set = vmw_master_set, > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h > index f6159acb8856..c4cd7fc350d9 100644 > --- a/include/drm/drm_drv.h > +++ b/include/drm/drm_drv.h > @@ -94,6 +94,16 @@ enum drm_driver_feature { > * synchronization of command submission. > */ > DRIVER_SYNCOBJ_TIMELINE = BIT(6), > + /** > + * @DRIVER_VIRTUAL: > + * > + * Driver is running on top of virtual hardware. The most significant > + * implication of this is a requirement of special handling of the > + * cursor plane (e.g. cursor plane has to actually track the mouse > + * cursor and the clients are required to set hotspot in order for > + * the cursor planes to work correctly). > + */ > + DRIVER_VIRTUAL = BIT(7),I think the naming here is unfortunate, because people will vonder why e.g. vkms doesn't set this, and then add it, and confuse stuff completely. Also it feels a bit wrong to put this onto the driver, when really it's a cursor flag. I guess you can make it some kind of flag in the drm_plane structure, or a new plane type, but putting it there instead of into the "random pile of midlayer-mistake driver flags" would be a lot better. Otherwise I think the series looks roughly how I'd expect it to look. -Daniel> > /* IMPORTANT: Below are all the legacy flags, add new ones above. */ > > diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h > index e0a73a1e2df7..3e5c36891161 100644 > --- a/include/drm/drm_file.h > +++ b/include/drm/drm_file.h > @@ -223,6 +223,18 @@ struct drm_file { > */ > bool is_master; > > + /** > + * @supports_virtual_cursor_plane: > + * > + * This client is capable of handling the cursor plane with the > + * restrictions imposed on it by the virtualized drivers. > + * > + * The implies that the cursor plane has to behave like a cursor > + * i.e. track cursor movement. It also requires setting of the > + * hotspot properties by the client on the cursor plane. > + */ > + bool supports_virtual_cursor_plane; > + > /** > * @master: > * > -- > 2.34.1 >-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch