Features/VirtioVsock: Difference between revisions
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virtio-vsock is a ''host/guest communications device''. | virtio-vsock is a ''host/guest communications device''. It allows applications in the guest and host to communicate. This can be used to implement hypervisor services and guest agents (like qemu-guest-agent or SPICE vdagent). | ||
* POSIX Sockets API so existing networking applications require minimal modification (unlike virtio-serial char devices) | |||
* Listen sockets can accept connections from multiple clients (unlike virtio-serial char devices) | |||
* No address configuration required inside the guest | |||
* No Ethernet or TCP/IP for a reduced attack surface for hypervisor services | |||
* Can be used with VMs that have no network interfaces | |||
Sockets are created with the AF_VSOCK address family. | Sockets are created with the AF_VSOCK address family. The SOCK_STREAM socket type is currently implemented for in-order, guaranteed stream semantics. | ||
==Code== | ==Code== | ||
* Virtio specification: [ | * Virtio specification: [https://stefanha.github.com/virtio HTML] or [https://github.com/stefanha/virtio virtio.git] | ||
* Linux kernel: [https://github.com/stefanha/linux/tree/vsock stefanha's linux.git] | * Linux kernel: Upstream since Linux 4.8, or see [https://github.com/stefanha/linux/tree/vsock stefanha's linux.git] | ||
* QEMU: [https://github.com/stefanha/qemu/tree/vsock stefanha's qemu.git] | * QEMU: Upstream since QEMU 2.8, or see [https://github.com/stefanha/qemu/tree/vsock stefanha's qemu.git] | ||
==Packages== | |||
* [https://copr.fedorainfracloud.org/coprs/stefanha/vsock/ Fedora Copr repo] | |||
==Quickstart== | |||
* Host kernel requirements: CONFIG_VHOST_VSOCK=m | |||
* Guest kernel requirements: CONFIG_VIRTIO_VSOCKETS=m | |||
Launch a guest and assign it CID 3: | |||
(host)# qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ... | |||
==Language bindings== | |||
* C - use <linux/vm_sockets.h> | |||
* Python - starting from Python 3.7 | |||
* Go - [https://github.com/mdlayher/vsock Matt Layher's vsock module] | |||
* Rust | |||
** [https://docs.rs/crate/libc libc crate] (libc::sockaddr_vm, libc::VMADDR_*) | |||
** [https://docs.rs/crate/nix nix crate] (nix::sys::socket::VsockAddr) | |||
==Projects using vsock== | |||
* [https://github.com/stefanha/nc-vsock nc-vsock] - a netcat-like utility for AF_VSOCK | |||
* [https://www.xpra.org/trac/wiki/Network xpra] - X11 persistent remote display server and client | |||
* [https://github.com/clownix/cloonix_vsock cloonix_vsock] - PTY over AF_VSOCK | |||
* [https://github.com/stefano-garzarella/iperf-vsock iperf-vsock] - iperf3 with AF_VSOCK support | |||
* [http://www.dest-unreach.org/socat/ socat] - VSOCK-CONNECT and VSOCK-LISTEN addresses supported from socat 1.7.4 [2021-01-04] | |||
==Links== | ==Links== | ||
* KVM Forum 2015 presentation: [http://vmsplice.net/~stefan/stefanha-kvm-forum-2015.pdf virtio-vsock: Zero-configuration host/guest communication] (pdf) | * KVM Forum 2015 presentation: [http://vmsplice.net/~stefan/stefanha-kvm-forum-2015.pdf virtio-vsock: Zero-configuration host/guest communication] (pdf) | ||
* Connectathon 2016 presentation: [http://vmsplice.net/~stefan/stefanha-connectathon-2016.pdf NFS over virtio-vsock: Host/guest file sharing for virtual machines] (pdf) | |||
Latest revision as of 15:59, 11 January 2021
virtio-vsock is a host/guest communications device. It allows applications in the guest and host to communicate. This can be used to implement hypervisor services and guest agents (like qemu-guest-agent or SPICE vdagent).
- POSIX Sockets API so existing networking applications require minimal modification (unlike virtio-serial char devices)
- Listen sockets can accept connections from multiple clients (unlike virtio-serial char devices)
- No address configuration required inside the guest
- No Ethernet or TCP/IP for a reduced attack surface for hypervisor services
- Can be used with VMs that have no network interfaces
Sockets are created with the AF_VSOCK address family. The SOCK_STREAM socket type is currently implemented for in-order, guaranteed stream semantics.
Code
- Virtio specification: HTML or virtio.git
- Linux kernel: Upstream since Linux 4.8, or see stefanha's linux.git
- QEMU: Upstream since QEMU 2.8, or see stefanha's qemu.git
Packages
Quickstart
- Host kernel requirements: CONFIG_VHOST_VSOCK=m
- Guest kernel requirements: CONFIG_VIRTIO_VSOCKETS=m
Launch a guest and assign it CID 3:
(host)# qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
Language bindings
- C - use <linux/vm_sockets.h>
- Python - starting from Python 3.7
- Go - Matt Layher's vsock module
- Rust
- libc crate (libc::sockaddr_vm, libc::VMADDR_*)
- nix crate (nix::sys::socket::VsockAddr)
Projects using vsock
- nc-vsock - a netcat-like utility for AF_VSOCK
- xpra - X11 persistent remote display server and client
- cloonix_vsock - PTY over AF_VSOCK
- iperf-vsock - iperf3 with AF_VSOCK support
- socat - VSOCK-CONNECT and VSOCK-LISTEN addresses supported from socat 1.7.4 [2021-01-04]
Links
- KVM Forum 2015 presentation: virtio-vsock: Zero-configuration host/guest communication (pdf)
- Connectathon 2016 presentation: NFS over virtio-vsock: Host/guest file sharing for virtual machines (pdf)