Features/VirtioVsock: Difference between revisions
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==Code== | ==Code== | ||
* Virtio specification: [https://stefanha.github.com/virtio HTML] or [https://github.com/stefanha/virtio virtio.git] | * 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: Available 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: Available in QEMU 2.8, or see [https://github.com/stefanha/qemu/tree/vsock stefanha's qemu.git] | ||
* netcat-like utility: [https://github.com/stefanha/linux/blob/vsock-extras/nc-vsock.c nc-vsock] | * netcat-like utility: [https://github.com/stefanha/linux/blob/vsock-extras/nc-vsock.c nc-vsock] | ||
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==Quickstart== | ==Quickstart== | ||
QEMU: | QEMU: | ||
$ git clone | $ git clone git://git.qemu-project.org/qemu.git | ||
$ cd qemu | $ cd qemu | ||
$ ./configure --target-list=x86_64-softmmu | $ ./configure --target-list=x86_64-softmmu | ||
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Linux: | Linux: | ||
$ git clone | $ git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git | ||
$ cd linux | $ cd linux | ||
$ cp /boot/config-$(uname -r) .config | $ cp /boot/config-$(uname -r) .config | ||
Revision as of 14:56, 21 November 2016
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).
Unlike virtio-serial, virtio-vsock supports the POSIX Sockets API so existing networking applications require minimal modification. The Sockets API allows N:1 connections so multiple clients can connect to a server simultaneously.
The device has an address assigned automatically so no configuration is required inside the guest.
Sockets are created with the AF_VSOCK address family. The SOCK_STREAM socket type is currently implemented.
Code
- Virtio specification: HTML or virtio.git
- Linux kernel: Available since Linux 4.8, or see stefanha's linux.git
- QEMU: Available in QEMU 2.8, or see stefanha's qemu.git
- netcat-like utility: nc-vsock
Packages
Quickstart
QEMU:
$ git clone git://git.qemu-project.org/qemu.git $ cd qemu $ ./configure --target-list=x86_64-softmmu $ make
Linux:
$ git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git $ cd linux $ cp /boot/config-$(uname -r) .config $ make menuconfig # select CONFIG_VHOST_VSOCK=m and CONFIG_VIRTIO_VSOCKETS=m $ make install modules_install
To use vhost_vsock.ko you must boot into the new host kernel and modprobe vhost_vsock.
The guest should also use the kernel so that modprobe virtio_transport can load the vsock guest driver.
For details on host and guest boot, see go.sh. Use nc-vsock 2 1234 inside the guest to connect to vsock port 1234 on the host. Use nc-vsock -l 1234 on the host to listen on that port.
Testing
The vhost-vsock-test qtest replays packets from a JSON file and verifies that the expected reply is received.
The JSON test file format is described in a README.
$ cd qemu
$ make -j4
$ make tests/vhost-vsock-test
$ sudo QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64 QTEST_QEMU_IMG=qemu-img MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM % 255 + 1))} gtester -k --verbose -m=quick tests/vhost-vsock-test -o /dev/stderr
Create and edit test cases in tests/vhost-vsock-test-data/*.json.
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)