virtio-gpu: add blob resource support.
vhost-user-gpu: security fixes.

# gpg: Signature made Thu 27 May 2021 15:23:25 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vga-20210527-pull-request: (23 commits)
  virtio-gpu: Update cursor data using blob
  virtio-gpu: Add virtio_gpu_set_scanout_blob
  virtio-gpu: Factor out update scanout
  virtio-gpu: Add helpers to create and destroy dmabuf objects
  ui/pixman: Add qemu_pixman_to_drm_format()
  virtio-gpu: Add virtio_gpu_resource_create_blob
  virtio-gpu: Add initial definitions for blob resources
  virtio-gpu: Refactor virtio_gpu_create_mapping_iov
  virtio-gpu: Refactor virtio_gpu_set_scanout
  virtio-gpu: Add virtio_gpu_find_check_resource
  stubs: Add stubs for udmabuf helpers
  virtio-gpu: Add udmabuf helpers
  headers: Add udmabuf.h
  ui: Get the fd associated with udmabuf driver
  hw/display/qxl: Set pci rom address aligned with page size
  vhost-user-gpu: abstract vg_cleanup_mapping_iov
  vhost-user-gpu: fix OOB write in 'virgl_cmd_get_capset' (CVE-2021-3546)
  vhost-user-gpu: fix memory leak in 'virgl_resource_attach_backing' (CVE-2021-3544)
  vhost-user-gpu: fix memory leak in 'virgl_cmd_resource_unref' (CVE-2021-3544)
  vhost-user-gpu: fix memory leak while calling 'vg_resource_unref' (CVE-2021-3544)
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>