Add vhost-device-media backend for virtio-media

Cargo.toml

@@ -8,6 +8,7 @@ members = [
     "vhost-device-gpu",
     "vhost-device-i2c",
     "vhost-device-input",
+    "vhost-device-media",
     "vhost-device-rng",
     "vhost-device-scsi",
     "vhost-device-scmi",

vhost-device-media/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+## Unreleased
+
+### Added
+
+### Changed
+
+### Fixed
+
+### Deprecated
+
+## v0.1.0
+
+First release

vhost-device-media/Cargo.toml

@@ -0,0 +1,48 @@
+[package]
+name = "vhost-device-media"
+version = "0.1.0"
+authors = ["Albert Esteve <aesteve@redhat.com>"]
+description = "A virtio-media device using the vhost-user protocol."
+repository = "https://github.com/rust-vmm/vhost-device"
+keywords = ["vhost", "media", "virt", "backend"]
+license = "Apache-2.0 OR BSD-3-Clause"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+default = ["v4l2-proxy"]
+v4l2-proxy = ["v4l2r"]
+ffmpeg = ["v4l2r", "virtio-media-ffmpeg-decoder"]
+simple-capture = ["v4l2r"]
+
+[dependencies]
+bitflags = "2.6.0"
+clap = { version = "4.5.20",  features = ["derive"] }
+env_logger = "0.11.5"
+epoll = "4.3.3"
+num_enum = "0.7.3"
+log = "0.4.22"
+libc = "0.2.162"
+thiserror = "2.0.3"
+anyhow = "1.0.93"
+futures-executor = { version = "0.3.31", features = ["thread-pool"] }
+vhost = { git = "https://github.com/rust-vmm/vhost", branch = "main", features = ["vhost-user-backend"] }
+vhost-user-backend = { git = "https://github.com/rust-vmm/vhost", branch = "main"}
+virtio-bindings = "0.2.5"
+virtio-queue = "0.17.0"
+vm-memory = { version = "0.17.1", features = ["backend-mmap", "backend-atomic"] }
+vmm-sys-util = "0.15.0"
+ref-cast = "1.0.23"
+virtio-media = { git = "https://github.com/chromeos/virtio-media", rev = "c6cc93a"}
+virtio-media-ffmpeg-decoder = { git = "https://github.com/chromeos/virtio-media/", package = "virtio-media-ffmpeg-decoder", rev = "c6cc93a", optional = true}
+v4l2r = { git =  "https://github.com/Gnurou/v4l2r", rev = "7b44138", optional = true }
+zerocopy = { version = "0.8.27", features = ["derive"] }
+
+[dev-dependencies]
+assert_matches = "1.5.0"
+rstest = "0.26.1"
+tempfile = "3.14.0"
+virtio-queue = { version = "0.17.0", features = ["test-utils"] }
+vm-memory = { version = "0.17.1", features = ["backend-mmap", "backend-atomic"] }
+zerocopy = { version = "0.8.27", features = ["derive"] }

vhost-device-media/LICENSE-APACHE

@@ -0,0 +1 @@
+../LICENSE-APACHE

vhost-device-media/LICENSE-BSD-3-Clause

@@ -0,0 +1 @@
+../LICENSE-BSD-3-Clause

vhost-device-media/README.md

@@ -0,0 +1,72 @@
+# vhost-device-media
+
+A virtio-media device using the vhost-user protocol.
+
+This crate provides a vhost-user backend for virtio-media devices. It is an implementation of the VIRTIO Media Device specification, which can be found on [virtio-spec v1.4](https://docs.oasis-open.org/virtio/virtio/v1.4/virtio-v1.4.html). The purpose of this device is to provide a standardized way for virtual machines to access media devices on the host.
+
+The low-level implementation of the virtio-media protocol is provided by the device crate from the [virtio-media](https://github.com/chromeos/virtio-media) repository.
+
+## Synopsis
+
+```console
+vhost-device-media --socket-path <SOCKET> --v4l2-device <V4L2_DEVICE> --backend <BACKEND>
+```
+
+## Description
+
+
+## Options
+
+```text
+     --socket-path <SOCKET>
+            vhost-user Unix domain socket path
+
+     --v4l2-device <V4L2_DEVICE>
+            Path to the V4L2 media device file. Defaults to /dev/video0.
+
+     --backend <BACKEND>
+            Media backend to be used. [possible values: simple-capture, v4l2-proxy, ffmpeg-decoder]
+
+     -h, --help
+            Print help
+
+     -V, --version
+            Print version
+```
+
+## Examples
+
+Launch the backend on the host machine:
+
+```shell
+host# vhost-device-media --socket-path /tmp/media.sock --v4l2-device /dev/video0 --backend v4l2-proxy
+```
+
+With QEMU, you can add a `virtio` device that uses the backend's socket with the following flags:
+
+```text
+-chardev socket,id=vmedia,path=/tmp/media.sock \
+-device vhost-user-media-pci,chardev=vmedia,id=media
+```
+
+## Features
+
+The following backends are available:
+
+- **simple-capture**: A simple video capture device generating a pattern, purely software-based and thus not requiring any kind of hardware. Can be used for testing purposes.
+- **v4l2-proxy**: A proxy device for host V4L2 devices, i.e. a device allowing to expose a host V4L2 device to the guest almost as-is.
+- **ffmpeg-decoder**: A software-based video decoder backend using FFmpeg.
+
+## Limitations
+
+This crate is currently under active development.
+
+- **dmabuf memory sharing**: DMA buffer (dmabuf) support for zero-copy memory sharing between guest and host and through multiple virtio devices using VirtIO shared objects is not yet implemented. Currently, all memory operations use regular memory mappings.
+- **Kernel driver availability**: The virtio-media kernel driver is still being upstreamed to the Linux kernel and may not be available in all kernel versions. Check [virtio-media](https://github.com/chromeos/virtio-media) for instructions on how to build the OOT module.
+
+## License
+
+This project is licensed under either of
+
+- [Apache License](http://www.apache.org/licenses/LICENSE-2.0), Version 2.0
+- [BSD-3-Clause License](https://opensource.org/licenses/BSD-3-Clause)