drm/i915/gvt: set guest display buffer as readonly

We shouldn't allow write for exposed guest display buffer which
doesn't make sense. So explicitly set read only flag for display
dmabuf allocated object.

Fixes: e546e281d33d ("drm/i915/gvt: Dmabuf support for GVT-g")
Cc: Tina Zhang <tina.zhang@intel.com>
Acked-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20191212084614.1100-1-zhenyuw@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
index e451298d11c32adc8fedad9e86341ee308ccf8d8..ee0f3094e6d03555fb5c0041a3785452df745d6e 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/dmabuf.c
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
@@ -163,6 +163,7 @@ static struct drm_i915_gem_object *vgpu_create_gem(struct drm_device *dev,
        drm_gem_private_object_init(dev, &obj->base,
                roundup(info->size, PAGE_SIZE));
        i915_gem_object_init(obj, &intel_vgpu_gem_ops, &lock_class);
+       i915_gem_object_set_readonly(obj);
 
        obj->read_domains = I915_GEM_DOMAIN_GTT;
        obj->write_domain = 0;