Red Hat's virtual desktop: Spice__spice

Excerpt from http://os.51cto.com/art/201201/311464.htm

SPICE (Independent Computing Environment Simple Protocol) is one of the three major technical components of the Red Hat Enterprise Virtualization Desktop Edition, with adaptive Remote commit protocol, which provides the exact same end-user experience as the physical desktop. It contains 3 components:

SPICE driver:spice drives are stored in each virtual desktop component;

SPICE Device:spice devices exist in the Red Hat Enterprise virtualization hypervisor components;

The SPICE Client:spice client is a component on a terminal device that can be either a thin client or a dedicated PC for access to each virtual desktop.

These three components work together to determine the most efficient location for processing graphics to maximize user experience and reduce system load. If the client is strong enough, Spice sends a graphics command to the client and processes the graphics in the client, significantly reducing the load on the server. On the other hand, if the client is not strong enough to handle graphics on the host computer, graphics processing does not require much spice from the CPU's point of view. Figure 1 is a schematic diagram of the spice three components.

Figure-1 Spice three components

The spice architecture is shown in Figure 2.

Figure 2 Spice Architecture

Spice works by creating several common interfaces or "channels" that are highly abstract, so they can be used on a variety of platforms. The main channel includes six channels: The main channel display channel input channel mouse control channel playback channel record channel

Each channel can be a separate stream of data. The spice protocol, which was used by Qumranet's main product Solidice, provides the same user experience as the real PC, which VNC cannot compare with spice we can play high-definition video and audio directly in the virtual machine. Two pairs, such as table 1.

	SPICE	Vnc
BIOS Screen Display	Yes	Yes
Full color support	Yes	Yes
Change resolution	Yes	Yes
Multiple Monitors	Multi-monitor support (up to 4 images)	Only one screen
Image transfer	Image and graphics transmission	Image transfer
Video playback Support	GPU Acceleration Support	No
Audio transmission	Bidirectional voice can be controlled	No
Mouse control	The client server can control	Server-side control
USB Transmission	USB can be transmitted over the network	No
Encryption	Communication can be encrypted using SSL	No

Spice's future features: Implement a virtual video card directly with DirectX and API. Accelerate CAD applications and multimedia applications. Faster switching with Game screen direct drawing process reduces flicker. Video Acceleration (DXVA) Video playback applications support DXVA, such as Windows Media players, to reduce CPU utilization on the client. 3D acceleration will run faster on a virtual desktop, such as OpenGL and 3D applications, Windows Aero Support, use of virtual desktops when Windows Vista and 7 can not be used now. You can dynamically change the virtual desktop resolution. Compatible iphones and ipads are controlled by devices such as iphones and ipads. Clipboard sharing you can share the Clipboard with the virtual desktop environment, and the data will allow you to collaborate with each other for seamless connectivity. Network Printer Sharing: Printers are allowed to access from the network, increasing availability.