cloud-hypervisor/vhost_rs
Yang Zhong 6fb7c3bbc2 vhost_rs: remove config space offset setting
There is one definition in message.rs file as below:
pub const VHOST_USER_CONFIG_OFFSET: u32 = 0x100

This definition is only for virtio mmio config space
and we will add this offset in virtio-mmio side and
not vhost user protocl side.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
2019-09-03 08:39:37 -07:00
..
src vhost_rs: remove config space offset setting 2019-09-03 08:39:37 -07:00
Cargo.toml build: Bulk update dependencies 2019-08-02 15:22:37 +02:00
LICENSE vhost_rs: Copy vhost crate from jiangliu/v1 2019-06-27 21:46:00 +02:00
LICENSE-BSD vhost_rs: Copy vhost crate from jiangliu/v1 2019-06-27 21:46:00 +02:00
LICENSE-MIT vhost_rs: Copy vhost crate from jiangliu/v1 2019-06-27 21:46:00 +02:00
README.md vhost_rs: Copy vhost crate from jiangliu/v1 2019-06-27 21:46:00 +02:00

vHost

A crate to support vhost backend drivers for virtio devices.

Kernel-based vHost Backend Drivers

The vhost drivers in Linux provide in-kernel virtio device emulation. Normally the hypervisor userspace process emulates I/O accesses from the guest. Vhost puts virtio emulation code into the kernel, taking hypervisor userspace out of the picture. This allows device emulation code to directly call into kernel subsystems instead of performing system calls from userspace. The hypervisor relies on ioctl based interfaces to control those in-kernel vhost drivers, such as vhost-net, vhost-scsi and vhost-vsock etc.

vHost-user Backend Drivers

The vhost-user protocol is aiming to implement vhost backend drivers in userspace, which complements the ioctl interface used to control the vhost implementation in the Linux kernel. It implements the control plane needed to establish virtqueue sharing with a user space process on the same host. It uses communication over a Unix domain socket to share file descriptors in the ancillary data of the message.

The protocol defines two sides of the communication, master and slave. Master is the application that shares its virtqueues, slave is the consumer of the virtqueues. Master and slave can be either a client (i.e. connecting) or server (listening) in the socket communication.