[Qemu-devel] [RFC 00/14] vhost-user backends for gpu & input virtio devices

[marcandre.lureau@redhat.com]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Hi,

vhost-user allows to drive a virtio device in a seperate process. So
far, it has been mainly used with virtio-net. It can work with other
devices such as input and gpu, as shown in this series.

Some of the benefits of using vhost-user are:
- parallelism, since the backend is running in a different process
- flexibility, since backends may be implemented by various parties
- some process isolation (virgl is fairly recent project and a lot of
security issues have been found, opengl isn't super safe either and it
may run on closed-source and large gl libraries), although having a
limited access to guest memory could be safer.

You can run the vhost-user-gpu backend with spice only (since
importing dmabuf requires an egl context, it's not easy to do it with
sdl/gtk ui), it provides the basic cursor/2d/3d rendering, but lacks
some features (such as resize):
-object vhost-user-backend,id=vug,cmd="./vhost-user-gpu"
-device virtio-vga,virgl=true,vhost-user=vug
-spice disable-ticketing,gl=on,unix,addr=/tmp/spice.soc

As for vhost-user-input, it takes an input device path:
-object vhost-user-backend,id=vuid,cmd="vhost-user-input /dev/input/event0"
-device virtio-input-host-pci,vhost-user=vuid

This is based on top of libvhost-user series sent earlier on ML. For
convenience, the branch is also available on github:
https://github.com/elmarco/qemu/ vhost-user-gpu

Comments welcome!

Marc-André Lureau (14):
  Add qemu_chr_open_socket()
  Add vhost-user-backend
  vhost-user: split vhost_user_read()
  vhost-user: add vhost_user_input_get_config()
  Add vhost-user backend to virtio-input-host
  contrib: add vhost-user-input
  misc: rename virtio-gpu.h header guard
  vhost: make sure call fd has been received
  qemu-char: use READ_RETRIES
  qemu-char: block during sync read
  console: add dpy_gl_scanout2()
  contrib: add vhost-user-gpu
  vhost-user: add vhost_user_gpu_set_socket()
  Add virtio-gpu vhost-user backend

 Makefile                               |    6 +
 Makefile.objs                          |    2 +
 backends/Makefile.objs                 |    2 +
 backends/vhost-user.c                  |  262 +++++++++
 configure                              |    5 +
 contrib/libvhost-user/libvhost-user.h  |    1 +
 contrib/vhost-user-gpu/Makefile.objs   |    7 +
 contrib/vhost-user-gpu/main.c          | 1012 ++++++++++++++++++++++++++++++++
 contrib/vhost-user-gpu/virgl.c         |  545 +++++++++++++++++
 contrib/vhost-user-gpu/virgl.h         |   24 +
 contrib/vhost-user-gpu/vugpu.h         |  155 +++++
 contrib/vhost-user-input/Makefile.objs |    1 +
 contrib/vhost-user-input/main.c        |  369 ++++++++++++
 docs/specs/vhost-user.txt              |    9 +
 hw/display/Makefile.objs               |    2 +-
 hw/display/vhost-gpu.c                 |  264 +++++++++
 hw/display/virtio-gpu-pci.c            |    6 +
 hw/display/virtio-gpu.c                |   75 ++-
 hw/display/virtio-vga.c                |    5 +
 hw/input/virtio-input-host.c           |   67 ++-
 hw/input/virtio-input.c                |    4 +
 hw/virtio/vhost-user.c                 |   97 ++-
 hw/virtio/vhost.c                      |    5 +
 hw/virtio/virtio-pci.c                 |    5 +
 include/hw/virtio/vhost-backend.h      |    5 +
 include/hw/virtio/virtio-gpu.h         |   11 +-
 include/hw/virtio/virtio-input.h       |    2 +
 include/sysemu/char.h                  |    2 +
 include/sysemu/vhost-user-backend.h    |   65 ++
 include/ui/console.h                   |   10 +
 qemu-char.c                            |   43 +-
 ui/console.c                           |   12 +
 ui/spice-display.c                     |   19 +
 33 files changed, 3073 insertions(+), 26 deletions(-)
 create mode 100644 backends/vhost-user.c
 create mode 100644 contrib/vhost-user-gpu/Makefile.objs
 create mode 100644 contrib/vhost-user-gpu/main.c
 create mode 100644 contrib/vhost-user-gpu/virgl.c
 create mode 100644 contrib/vhost-user-gpu/virgl.h
 create mode 100644 contrib/vhost-user-gpu/vugpu.h
 create mode 100644 contrib/vhost-user-input/Makefile.objs
 create mode 100644 contrib/vhost-user-input/main.c
 create mode 100644 hw/display/vhost-gpu.c
 create mode 100644 include/sysemu/vhost-user-backend.h

-- 
2.7.4