# -*- Mode: Python -*-
# vim: filetype=python
#
# Copyright (C) 2018 Red Hat, Inc.
#
# Authors:
# Marc-André Lureau <marcandre.lureau@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2 or
# later. See the COPYING file in the top-level directory.
##
# = vhost user backend discovery & capabilities
##
##
# @VHostUserBackendType:
#
# List the various vhost user backend types.
#
# @9p: 9p virtio console
# @balloon: virtio balloon
# @block: virtio block
# @caif: virtio caif
# @console: virtio console
# @crypto: virtio crypto
# @gpu: virtio gpu
# @input: virtio input
# @net: virtio net
# @rng: virtio rng
# @rpmsg: virtio remote processor messaging
# @rproc-serial: virtio remoteproc serial link
# @scsi: virtio scsi
# @vsock: virtio vsock transport
# @fs: virtio fs (since 4.2)
#
# Since: 4.0
##
{
'enum': 'VHostUserBackendType',
'data': [
'9p',
'balloon',
'block',
'caif',
'console',
'crypto',
'gpu',
'input',
'net',
'rng',
'rpmsg',
'rproc-serial',
'scsi',
'vsock',
'fs'
]
}
##
# @VHostUserBackendBlockFeature:
#
# List of vhost user "block" features.
#
# @read-only: The --read-only command line option is supported.
# @blk-file: The --blk-file command line option is supported.
#
# Since: 5.0
##
{
'enum': 'VHostUserBackendBlockFeature',
'data': [ 'read-only', 'blk-file' ]
}
##
# @VHostUserBackendCapabilitiesBlock:
#
# Capabilities reported by vhost user "block" backends
#
# @features: list of supported features.
#
# Since: 5.0
##
{
'struct': 'VHostUserBackendCapabilitiesBlock',
'data': {
'features': [ 'VHostUserBackendBlockFeature' ]
}
}
##
# @VHostUserBackendInputFeature:
#
# List of vhost user "input" features.
#
# @evdev-path: The --evdev-path command line option is supported.
# @no-grab: The --no-grab command line option is supported.
#
# Since: 4.0
##
{
'enum': 'VHostUserBackendInputFeature',
'data': [ 'evdev-path', 'no-grab' ]
}
##
# @VHostUserBackendCapabilitiesInput:
#
# Capabilities reported by vhost user "input" backends
#
# @features: list of supported features.
#
# Since: 4.0
##
{
'struct': 'VHostUserBackendCapabilitiesInput',
'data': {
'features': [ 'VHostUserBackendInputFeature' ]
}
}
##
# @VHostUserBackendGPUFeature:
#
# List of vhost user "gpu" features.
#
# @render-node: The --render-node command line option is supported.
# @virgl: The --virgl command line option is supported.
#
# Since: 4.0
##
{
'enum': 'VHostUserBackendGPUFeature',
'data': [ 'render-node', 'virgl' ]
}
##
# @VHostUserBackendCapabilitiesGPU:
#
# Capabilities reported by vhost user "gpu" backends.
#
# @features: list of supported features.
#
# Since: 4.0
##
{
'struct': 'VHostUserBackendCapabilitiesGPU',
'data': {
'features': [ 'VHostUserBackendGPUFeature' ]
}
}
##
# @VHostUserBackendCapabilities:
#
# Capabilities reported by vhost user backends.
#
# @type: The vhost user backend type.
#
# Since: 4.0
##
{
'union': 'VHostUserBackendCapabilities',
'base': { 'type': 'VHostUserBackendType' },
'discriminator': 'type',
'data': {
'input': 'VHostUserBackendCapabilitiesInput',
'gpu': 'VHostUserBackendCapabilitiesGPU'
}
}
##
# @VhostUserBackend:
#
# Describes a vhost user backend to management software.
#
# It is possible for multiple @VhostUserBackend elements to match the
# search criteria of management software. Applications thus need rules
# to pick one of the many matches, and users need the ability to
# override distro defaults.
#
# It is recommended to create vhost user backend JSON files (each
# containing a single @VhostUserBackend root element) with a
# double-digit prefix, for example "50-qemu-gpu.json",
# "50-crosvm-gpu.json", etc, so they can be sorted in predictable
# order. The backend JSON files should be searched for in three
# directories:
#
# - /usr/share/qemu/vhost-user -- populated by distro-provided
# packages (XDG_DATA_DIRS covers
# /usr/share by default),
#
# - /etc/qemu/vhost-user -- exclusively for sysadmins' local additions,
#
# - $XDG_CONFIG_HOME/qemu/vhost-user -- exclusively for per-user local
# additions (XDG_CONFIG_HOME
# defaults to $HOME/.config).
#
# Top-down, the list of directories goes from general to specific.
#
# Management software should build a list of files from all three
# locations, then sort the list by filename (i.e., basename
# component). Management software should choose the first JSON file on
# the sorted list that matches the search criteria. If a more specific
# directory has a file with same name as a less specific directory,
# then the file in the more specific directory takes effect. If the
# more specific file is zero length, it hides the less specific one.
#
# For example, if a distro ships
#
# - /usr/share/qemu/vhost-user/50-qemu-gpu.json
#
# - /usr/share/qemu/vhost-user/50-crosvm-gpu.json
#
# then the sysadmin can prevent the default QEMU GPU being used at all with
#
# $ touch /etc/qemu/vhost-user/50-qemu-gpu.json
#
# The sysadmin can replace/alter the distro default QEMU GPU with
#
# $ vim /etc/qemu/vhost-user/50-qemu-gpu.json
#
# or they can provide a parallel QEMU GPU with higher priority
#
# $ vim /etc/qemu/vhost-user/10-qemu-gpu.json
#
# or they can provide a parallel QEMU GPU with lower priority
#
# $ vim /etc/qemu/vhost-user/99-qemu-gpu.json
#
# @type: The vhost user backend type.
#
# @description: Provides a human-readable description of the backend.
# Management software may or may not display @description.
#
# @binary: Absolute path to the backend binary.
#
# @tags: An optional list of auxiliary strings associated with the
# backend for which @description is not appropriate, due to the
# latter's possible exposure to the end-user. @tags serves
# development and debugging purposes only, and management
# software shall explicitly ignore it.
#
# Since: 4.0
#
# Example:
#
# {
# "description": "QEMU vhost-user-gpu",
# "type": "gpu",
# "binary": "/usr/libexec/qemu/vhost-user-gpu",
# "tags": [
# "CONFIG_OPENGL_DMABUF=y"
# ]
# }
#
##
{
'struct' : 'VhostUserBackend',
'data' : {
'description': 'str',
'type': 'VHostUserBackendType',
'binary': 'str',
'*tags': [ 'str' ]
}
}
