Add license files for BSD-Alibaba, BSD-Google

Signed-off-by: Liu Jiang <gerry@linux.alibaba.com>

1 files changed, 20 insertions, 6 deletions

diff --git a/README.md b/README.md
index 6426bd6..c1c2ab6 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,24 @@
 # vHost
-A crate to implement the vHost ioctl interfaces and vHost-user protocol.
+A crate to support vhost backend drivers for virtio devices.
 
-## vHost Ioctl Interfaces
-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.
+## 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 Protocol
-The vHost-user protocol is aiming to complement 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.
+## 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.
+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.