NOVA Microhypervisor
C++ Assembly

NOVA Microhypervisor

This is the source code for the NOVA microhypervisor.

The NOVA microhypervisor combines microkernel and hypervisor functionality and provides an extremely small trusted computing base for user applications and virtual machines running on top of it. The microhypervisor implements a capability-based authorization model and provides basic mechanisms for virtualization, spatial and temporal separation, scheduling, communication, and management of platform resources.

NOVA can be used with a multi-server environment that implements additional operating-system services in user mode, such as device drivers, protocol stacks, and policies. On machines with hardware virtualization features, multiple unmodified guest operating systems can run concurrently on top of the microhypervisor.

This code is experimental and not feature complete. If it breaks, you get to keep both pieces.

Supported platforms

The NOVA microhypervisor runs on single- and multi-processor x86 machines that support ACPI.

The virtualization features are available on:

  • Intel CPUs with VMX, regardless of whether the CPU supports nested paging (EPT) or not.

  • AMD CPUs with SVM, regardless of whether the CPU supports nested paging (NPT) or not.

Building from source code

You need the following tools to compile the source code:

You can build a 32-bit microhypervisor binary as follows:

cd build; make ARCH=x86_32

You can build a 64-bit microhypervisor binary as follows:

cd build; make ARCH=x86_64


The NOVA microhypervisor can be started from a multiboot-compliant bootloader, such as GRUB or PXEGRUB. Here are some examples:

Boot from harddisk 0, partition 0

title         NOVA
kernel        (hd0,0)/boot/nova/hypervisor
module        (hd0,0)/...

Boot from TFTP server

title         NOVA
kernel        (nd)/boot/nova/hypervisor
module        (nd)/...

Command-Line Parameters

The following command-line parameters are supported for the microhypervisor. They must be separated by spaces.

  • iommu - Enables DMA and interrupt remapping.
  • keyb - Enables the microhypervisor to drive the keyboard.
  • serial - Enables the microhypervisor to drive the serial console.
  • spinner - Enables event spinners.
  • vtlb - Forces use of vTLB instead of nested paging (EPT/NPT).
  • nopcid - Disables TLB tags for address spaces.
  • novga - Disables VGA console.
  • novpid - Disables TLB tags for virtual machines.


The NOVA source code is licensed under the GPL version 2.

Copyright (C) 2009-2011 Udo Steinberg <>
Economic rights: Technische Universitaet Dresden (Germany)

Copyright (C) 2012-2013 Udo Steinberg, Intel Corporation.

NOVA is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

NOVA is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License version 2 for more details.


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