From faa29110b903fed29ba27bad3d0d8fcc7a8aa0fa Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alex=20Benn=C3=A9e?= Date: Thu, 16 Oct 2025 16:03:56 +0100 Subject: [PATCH] docs/system: merge vhost-user-input into vhost-user-contrib MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We might as well group all the contrib submissions together and gently dissuade people from using them in production. Update the references in vhost-user to neatly refer to the storage daemon and the various external rust backends. Reviewed-by: Manos Pitsidianakis Message-ID: <20251016150357.876415-12-alex.bennee@linaro.org> Signed-off-by: Alex Bennée --- docs/system/devices/virtio/index.rst | 2 +- .../devices/virtio/vhost-user-contrib.rst | 87 +++++++++++++++++++ .../devices/virtio/vhost-user-input.rst | 45 ---------- docs/system/devices/virtio/vhost-user.rst | 22 ++--- docs/system/devices/virtio/virtio-gpu.rst | 2 + 5 files changed, 101 insertions(+), 57 deletions(-) create mode 100644 docs/system/devices/virtio/vhost-user-contrib.rst delete mode 100644 docs/system/devices/virtio/vhost-user-input.rst diff --git a/docs/system/devices/virtio/index.rst b/docs/system/devices/virtio/index.rst index e3839e61824..c292101ade6 100644 --- a/docs/system/devices/virtio/index.rst +++ b/docs/system/devices/virtio/index.rst @@ -24,6 +24,6 @@ can also be off-loaded to an external process via :ref:`vhost user virtio-pmem.rst virtio-snd.rst vhost-user.rst - vhost-user-input.rst + vhost-user-contrib.rst .. _VirtIO specification: https://docs.oasis-open.org/virtio/virtio/v1.3/virtio-v1.3.html diff --git a/docs/system/devices/virtio/vhost-user-contrib.rst b/docs/system/devices/virtio/vhost-user-contrib.rst new file mode 100644 index 00000000000..48d04d2ade3 --- /dev/null +++ b/docs/system/devices/virtio/vhost-user-contrib.rst @@ -0,0 +1,87 @@ +vhost-user daemons in contrib +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +QEMU provides a number of :ref:`vhost_user` daemons in the contrib +directory. They were often written when vhost-user was initially added +to the code base. You should also consider if other vhost-user daemons +such as those from the rust-vmm `vhost-device repository`_ are better +suited for production use. + +.. _vhost-device repository: https://github.com/rust-vmm/vhost-device + +.. _vhost_user_block: + +vhost-user-block - block device +=============================== + +vhost-user-block is a backend for exposing block devices. It can +present a flat file or block device as a simple block device to the +guest. You almost certainly want to use the :ref:`storage-daemon` +instead which supports a wide variety of storage modes and exports a +number of interfaces including vhost-user. + +.. _vhost_user_gpu: + +vhost-user-gpu - gpu device +=========================== + +vhost-user-gpu presents a paravirtualized GPU and display controller. +You probably want to use the internal :ref:`virtio_gpu` implementation +if you want the latest features. There is also a `vhost_device_gpu`_ +daemon as part of the rust-vmm project. + +.. _vhost_device_gpu: https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-gpu + +.. _vhost_user_input: + +vhost-user-input - Input emulation +================================== + +The Virtio input device is a paravirtualized device for input events. + +Description +----------- + +The vhost-user-input device implementation was designed to work with a daemon +polling on input devices and passes input events to the guest. + +QEMU provides a backend implementation in contrib/vhost-user-input. + +Linux kernel support +-------------------- + +Virtio input requires a guest Linux kernel built with the +``CONFIG_VIRTIO_INPUT`` option. + +Examples +-------- + +The backend daemon should be started first: + +:: + + host# vhost-user-input --socket-path=input.sock \ + --evdev-path=/dev/input/event17 + +The QEMU invocation needs to create a chardev socket to communicate with the +backend daemon and access the VirtIO queues with the guest over the +:ref:`shared memory `. + +:: + + host# qemu-system \ + -chardev socket,path=/tmp/input.sock,id=mouse0 \ + -device vhost-user-input-pci,chardev=mouse0 \ + -m 4096 \ + -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on \ + -numa node,memdev=mem \ + ... + + +.. _vhost_user_scsi: + +vhost-user-scsi - SCSI controller +================================= + +The vhost-user-scsi daemon can proxy iSCSI devices onto a virtualized +SCSI controller. diff --git a/docs/system/devices/virtio/vhost-user-input.rst b/docs/system/devices/virtio/vhost-user-input.rst deleted file mode 100644 index 118eb78101c..00000000000 --- a/docs/system/devices/virtio/vhost-user-input.rst +++ /dev/null @@ -1,45 +0,0 @@ -.. _vhost_user_input: - -QEMU vhost-user-input - Input emulation -======================================= - -This document describes the setup and usage of the Virtio input device. -The Virtio input device is a paravirtualized device for input events. - -Description ------------ - -The vhost-user-input device implementation was designed to work with a daemon -polling on input devices and passes input events to the guest. - -QEMU provides a backend implementation in contrib/vhost-user-input. - -Linux kernel support --------------------- - -Virtio input requires a guest Linux kernel built with the -``CONFIG_VIRTIO_INPUT`` option. - -Examples --------- - -The backend daemon should be started first: - -:: - - host# vhost-user-input --socket-path=input.sock \ - --evdev-path=/dev/input/event17 - -The QEMU invocation needs to create a chardev socket to communicate with the -backend daemon and access the VirtIO queues with the guest over the -:ref:`shared memory `. - -:: - - host# qemu-system \ - -chardev socket,path=/tmp/input.sock,id=mouse0 \ - -device vhost-user-input-pci,chardev=mouse0 \ - -m 4096 \ - -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on \ - -numa node,memdev=mem \ - ... diff --git a/docs/system/devices/virtio/vhost-user.rst b/docs/system/devices/virtio/vhost-user.rst index 9c9a28df380..f556a840e99 100644 --- a/docs/system/devices/virtio/vhost-user.rst +++ b/docs/system/devices/virtio/vhost-user.rst @@ -27,37 +27,37 @@ platform details for what sort of virtio bus to use. - Notes * - vhost-user-blk - Block storage - - See contrib/vhost-user-blk + - :ref:`storage-daemon` * - vhost-user-fs - File based storage driver - - See https://gitlab.com/virtio-fs/virtiofsd + - `virtiofsd `_ * - vhost-user-gpio - Proxy gpio pins to host - - See https://github.com/rust-vmm/vhost-device + - `vhost-device-gpio `_ * - vhost-user-gpu - GPU driver - - See contrib/vhost-user-gpu + - `vhost-device-gpu `_ or :ref:`vhost_user_gpu` * - vhost-user-i2c - Proxy i2c devices to host - - See https://github.com/rust-vmm/vhost-device + - `vhost-device-i2c `_ * - vhost-user-input - Generic input driver - - :ref:`vhost_user_input` + - `vhost-device-input `_ or :ref:`vhost_user_input` * - vhost-user-rng - Entropy driver - - See https://github.com/rust-vmm/vhost-device + - `vhost-device-rng `_ * - vhost-user-scmi - System Control and Management Interface - - See https://github.com/rust-vmm/vhost-device + - `vhost-device-scmi `_ * - vhost-user-snd - Audio device - - See https://github.com/rust-vmm/vhost-device/staging + - `vhost-device-sound `_ * - vhost-user-scsi - SCSI based storage - - See contrib/vhost-user-scsi + - :ref:`vhost_user_scsi` * - vhost-user-vsock - Socket based communication - - See https://github.com/rust-vmm/vhost-device + - `vhost-device-vsock `_ The referenced *daemons* are not exhaustive, any conforming backend implementing the device and using the vhost-user protocol should work. diff --git a/docs/system/devices/virtio/virtio-gpu.rst b/docs/system/devices/virtio/virtio-gpu.rst index 39d2fd2d21c..0f4bb304a9b 100644 --- a/docs/system/devices/virtio/virtio-gpu.rst +++ b/docs/system/devices/virtio/virtio-gpu.rst @@ -1,6 +1,8 @@ .. SPDX-License-Identifier: GPL-2.0-or-later +.. _virtio_gpu: + VirtIO GPU ========== -- 2.47.3