HP Integrity VM Accelerated Virtual I/O Overview

Host
SCSI and LAN Stack
Driver
Physical Hardware
H/W
Unmodified Guest Driver
Guest
Monitor
Device Emulation
SCSI and LAN Stack
Protocol Driver
Host
SCSI and LAN Stack
Driver
Physical Hardware
H/W
Unmodified Guest Driver
Guest
Monitor
Device Emulation
SCSI and LAN Stack
Protocol Driver
There are three key items to note here:
1. Device Emulation – Because the guest driver is emulated, the Integrity VM monitor must
trap and emulate any hardware level actions. In particular, initiating control and I/O requests
require the monitor to trap, emulate and then forward the I/O request onto the host for
processing.
2. Protocol Driver – The protocol driver processes control and I/O requests that have been
emulated by the Integrity VM monitor. This requires the protocol driver to interact with the host
I/O stack to successfully complete the request.
3. I/O Stack processing – Both the guest and the host process the I/O request using the I/O
stack twice.
Benefits of emulated Integrity VM guest drivers:
• No Guest OS modifications for virtual machine support.
• Reduces verification and support costs.
• Boot/Dump and OS install support are enabled by default.
Drawbacks of emulated Integrity VM guest drivers:
• I/O performance is slow and does not support I/O intensive applications.