WindowsXPUnderQemuHowTo-gliethttp-ChinaUnix博客

Contents

Before installing this Windows emulator, consider whether or not it's truly necessary for you. In most cases, its functionality is provided by a free Linux program (see ).

Consider also instead of Qemu, if you only need to run a single Windows program.

Most of the stuff in this page is not specific to installing Windows XP under Qemu; it can be used to install other operating systems as well.

Running Windows Under Ubuntu 7.04/7.10

can run an OS inside another OS - for example, Windows under Linux. QEmu uses kqemu, an acceleration driver included in Ubuntu 7.04 Feisty Fawn to run Windows at usable speed.

Ubuntu 7.04 Feisty Fawn also includes a new version of rdesktop that can be used to start individual desktop apps from the VM on your normal desktop. See . This also works in Ubuntu 7.10 Gusty Gibbon.

Note: Most computers purchased since 2006 support VT or Pacifica, technologies that provide hardware support for virtualization. To see if your system includes these technologies, run the following:

grep -E '^flags.*(vmx|svm)' /proc/cpuinfo

If there are any results and you have Hardy 8.04, install the 'kvm' package, skip to step 10 and replace 'qemu' in the commands with 'kvm'. Also for multicore machines enjoy the benefits of using '-smp 2' as an option. For older versions of ubuntu see as another possibility for virtualizing other operating systems.

Note: Even if you get no output from the above command, your computer may actually support virtualization in hardware. Some machines are delivered with hardware virtualization disabled in the BIOS. Other machines require an update to the latest BIOS to enable virtualization.

To install Ubuntu inside QEmu, please read .

Installing Windows in QEmu with Feisty 7.04 and Gutsy 7.10

While the following guide uses Windows XP, older versions of Windows work fine, and may be preferred due to their increased speed.

As of Intrepid, the only thing that I had to do was to add myself to the kqemu group (step 6).
First you need to install qemu kqemu-source and module assistant from the Universe Repository. (In Gutsy(7.10),Use the synaptic package manager, search for kqemu and install kqemu-source. Module Assistant is not needed.)

Next you need to build the kqemu module from Ubuntu's package

sudo module-assistant prepare
sudo module-assistant auto-install kqemu

If it doesn't work, you can try:

cd /usr/src/kqemu*
sudo ./configure
sudo make
sudo ./install.sh

Next you need to configure udev to create the /dev/kqemu device node upon loading the kqemu module
- Create /etc/udev/rules.d/60-kqemu.rules
  - ```
  gksudo gedit /etc/udev/rules.d/60-kqemu.rules  
```
  with the following content: (the order of GROUP and MODE seems to matter, so be sure to add a new line at the end of the file)
```
  KERNEL=="kqemu", NAME="%k", GROUP="kqemu", MODE="0660"  
```
Change the content of /etc/modprobe.d/kqemu.conf to
- ```
options kqemu major=0
```
Create a group "kqemu" and add all users who should be allowed to use QEMU with acceleration to this group
- ```
sudo addgroup --system kqemu
sudo adduser $USER kqemu 
```
- Make sure to update your environment before proceeding to reflect that your user is now part of the
  - kqemu group (for example by logging out and in).
Force udev to reload its config files
- ```
sudo /etc/init.d/udev reload
```

Load the kqemu module

sudo update-modules   # this is deprecated under Hardy, instead use "sudo depmod -a"
sudo modprobe kqemu

Check that the permissions are right
- ```
$ ls -l /dev/kqemu
crw-rw---- 1 root kqemu 10, 62 2007-07-22 15:36 /dev/kqemu
```
- If the permissions are wrong, it is probably because your udev rule wasn't read properly. Try re-loading the module
  - ```
  sudo modprobe -r kqemu
  sudo modprobe kqemu
```
and see if that clears the problem. If not, add OWNER="youruser" to the end of the udev rule and try again
If you want to load the kqemu module upon system start in the future, add "kqemu" to your /etc/modules file
- ```
gksu gedit /etc/modules 
```
Create a virtual drive for Windows
- ```
qemu-img create -f qcow windows.img 2G
```
- This creates a two gigabyte virtual drive, stored as a single file called windows.img in the location where you ran the command. Any size above 1.5GB (the minimum to run Windows XP) is fine. The virtual drive will start out as a small file, and will only use the space you specified when it reaches capacity, due to the qcow file format used.
- Note: If you want to install Windows XP Service Pack 2 + Updates, 2 GB is not enough for the image size. Use at least 3-4 GB.
- Note: Consider using as much disk space as you can afford. Resizing NTFS partitions isn't fun, and hard disk space is cheap.
- Note: If you use qcow images, you will not be able to mount the image within Ubuntu. You can omit '-f qcow' and create a mountable image, but this will mean that the size of the virtual drive will be fixed and larger. Instructions to convert a raw drive to a qcow drive appear at the end of this page.
Install Windows XP. Put the CD in the drive and run:
- ```
qemu -localtime -cdrom /dev/cdrom -m 384 -boot d windows.img
```
- Note: Your CD drive might be under a slightly different name like /dev/cdrom1. Go to /dev to see what location you should use.
This starts QEmu using the time from Ubuntu, windows.img as the hard disk file, /dev/cdrom as the CD, 384 MB of memory (a good minimum for XP) and will boot from the CD.

Alternatively, you can use a .iso image file

qemu -localtime -cdrom cdimagefile.iso -m 384 -boot d windows.img

If you're having trouble creating the Windows partition during Windows installation, check that you have read and write access to the disk image. Use this command to set the file permissions for the windows.img file so that all users in the kqemu group can access the virtual disk
- ```
chmod 660 windows.img
sudo chown $USER:kqemu windows.img
```
- Note to 64 bit users: Use 'qemu-system-x86_64' instead of 'qemu'. Otherwise the "-kernel-kqemu" option will not work.
- Note for Windows 2000: Add the option '-win2k-hack'. Otherwise the install may fail with "Not enough disk space" even when that isn't the case.
QEmu will start, boot from the CD, and load the XP installer. The installer works like any other Windows install for the most part. However, on some systems the last part of the initial install, pictured, below, will stick around for a very long time. In this case, just reboot (restart QEmu), and the installer will proceed past this point.
After a few 'reboots' of QEmu you will be running Windows XP.
Clicking on the QEmu window will take control of the Windows cursor. To go back to Linux, press Ctrl + Alt and to toggle fullscreen press Ctrl + Alt + F

Networking

QEmu provides two modes of networking. In both modes, a virtual network adapter is created inside Windows XP guest.

User mode networking

In user mode networking, QEmu manages network interface internally in the user mode emulator application. QEmu provides DHCP host which assigns a dynamic IP for the guest OS. TCP and UDP ports can be redirected from the host OS to the guest OS using QEmu command line parameters.

         QEMU VLAN      <------>  Firewall/DHCP server <-----> Host network
                           |          (10.0.2.2)
                           |
                           ---->  DNS server (10.0.2.3)
                           |     
                           ---->  SMB server (10.0.2.4)

Pros

Easy to set up

Cons

Only TCP and UDP connections are available by default. Ping command, for example, doesn't work inside the guest OS
Incoming connections must be configured beforehand

TAP network

In TAP networking, QEmu connects the guest OS ethernet to the host OS using TAP network bridge. Linux creates a virtual network interface (tap0) which appears in ifconfig listing as other network interfaces. Furthermore, it is possible to bridge network traffic to the guest OS using normal Linux network bridging functionalities.

For examples, see following pages

Pros

Provides full emulated IP stack

Cons

Difficult to set up. The set-up is especially cumbersome if you try to run QEmu without root privileges.

VDE and Dnsmasq

This is an alternative to TAP networking. Most of this is from the page and .

Caution: The following package, "dnsmasq" provides dns, tftp and dhcpd services. An LTSP standalone server would be affected because dnsmasq would interfere with the dhcpd and tftp services.

* Install the packages vde dnsmasq:

sudo apt-get install vde dnsmasq

* In the file /etc/sysctl uncomment the following line to allow IP forwarding:

net.ipv4.conf.default.forwarding=1

* In the file /etc/modules, add a new line with "tun", to make that module load on boot.

* Add the new network interface. Edit the file /etc/network/interfaces and paste this:

auto qtap0
iface qtap0 inet static
        address 10.111.111.254
        netmask 255.255.255.0
        pre-up /sbin/modprobe ipt_MASQUERADE
        pre-up /usr/bin/vde_switch --tap qtap0 --sock /var/run/vde.ctl  \
                                   --daemon --group vde2-net --mod 775  \
                                   --mgmt /var/run/vde.mgmt --mgmtmode 770  \
                                   --pidfile /var/run/vde_switch.pid
        pre-up /etc/init.d/dnsmasq restart
        up iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
        down iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
        post-down kill -s HUP `cat /var/run/vde_switch.pid`

Temporary vdeq control sockets are created in /tmp, the vde_switch socket in /var/run/vde.ctl/ , and the management socket is /var/run/vde.mgmt .

More info about vde_switch (VDE):

* Configure DNSmasq. Edit the file /etc/dnsmasq.conf and change the following options:

user=nobody
domain=qemu.lan
interface=qtap0
dhcp-range=10.111.111.1,10.111.111.253,255.255.255.0,10.111.111.255,8h

To avoid the need for root privileges add the group "vde2-net" to all users that will use VDE (log-out and log-in for this to take effect)

sudo usermod -aG vde2-net $USER

Either restart the PC or simply do:

sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
sudo modprobe tun
sudo ifup qtap0

Then you will have a virtual network on qtap0 interface. VM will be able to connect to the Internet (because of the iptable line on /etc/network/interfaces), but will not be accessible from it.

To run a VM with the virtual network use vdeqemu instead of qemu:

vdeqemu -net vde,vlan=0 -net nic,vlan=0 -m 384 -boot c windows.img

See for more details on using qemu-launcher and qemuctl with VDE and KVM hardware virtualisation

Additional Options

It's not much use having an XP installation if you can't transfer files between Ubuntu and XP. Fortunately, QEMU sets up a virtual LAN and DHCP server for you. You can transfer files to and from XP just as if it was on a real LAN. You can also browse the net and download files and do all the network stuff you would do on a real networked XP box.

QEmu supports file sharing between the VM and host if you have . The following assumes you have a share called 'qemu_share' in your home directory intended to transfer files between Ubuntu and Windows.

To set this up, start QEmu with the following command:

qemu -smb $HOME/qemu_share -m 384 -localtime windows.img

Inside Windows, you can access the shared drive with the following command from a DOS prompt. For example, to map Windows drive 'e' to the share

net use e: \\10.0.2.2\qemu_share

The IP address of Ubuntu will always be 10.0.2.2. If you have running servers on your Ubuntu box, they can also be accessed at this IP address (e.g. )

USB Tablet Emulation

NOTE: Changes made to the Ubuntu Gutsy Gibbon and Hardy Heron distribution code have broken the USB functionality in QEMU. If you need USB functionality with QEMU please see the details here: .

QEmu can emulate a USB tablet input device instead of an ordinary mouse. Since a tablet reports the pointer position in absolute coordinates, it is possible to have the guest pointer track the host pointer position directly without a mouse grab. Running QEmu with the command line options "-usb -usbdevice tablet" enables USB emulation and the tablet input device:

qemu -m 384 -localtime -usb -usbdevice tablet windows.img

Windows XP automatically uses the tablet without having to install any additional drivers.

(TODO: Maybe these options should simply be added to the default ones at the top of the page. Not everyone will find this paragraph, and the feature is so useful that it should probably be recommended for general use. --)

Mounting A Virtual Drive

You can also mount the QEmu virtual disk just like any other drive. QCOW images cannot be mounted. If the drive was created in qcow format you'll need to convert it first, see .

Make sure you are NOT running QEMU when you do this. Windows will not recognize anything you write while running QEMU. Even worse, it will perceive that something changed and will run the chkdsk the next time you start QEMU. Also, you may only be able to read something wrote by windows after the windows is closed.

To mount the drive, create a directory '/media/qemu'. Then run

sudo mount -t ntfs -o loop,offset=32256 windows.raw /media/qemu

Or you can have it automatically mounted by adding the following line to /etc/fstab

/home/user/windows.raw /media/qemu ntfs rw,user,loop,offset=32256 0 0

Saving and Restoring the State of the VM

You can quickly save and restore the state of your Windows System using QEmu's 'overlay images'. Once you have done your initial install, you can create an overlay image and run QEMU off this. The overlay image is very much smaller that the original image and will only contain changes made since the original install. If you trash your XP installation, you can simply delete the overlay image and create a new one from the original image.

To create an overlay image, use the qemu-image program. To create an image windows.ovl from windows.img, issue the following

qemu-img create -b windows.img -f qcow windows.ovl

To run Windows, you would now use

qemu windows.ovl -enable-audio -user-net -localtime -smb qemu_share

If the winxp.ovl installation is ruined, you can delete it, and start QEmu using the winxp.img file. But you will lose changes made since the original install.

Snapshot mode

With the option -snapshot, QEmu writes to temporary files instead of disk image files. In this case, the raw disk image you use is not written back. You can however force the write back by pressing C-a s. The snapshot mode if useful to try a program that you don't trust (you should never trust a closed source program).

QEmu Monitor

QEmu also accepts commands from the shell while it is running. To do this, though, you need to press CTRL+ALT+2 with the QEmu window active. This brings up the QEmu Monitor. From here, you can swap CDs, send keypresses to the emulator, suspend to disk and so on. See the official documentation for full details.

eject cdrom
change cdrom /path/to/some.iso

To exit the QEmu monitor press CTRL+ALT+1

Converting a qcow image to a raw file

To convert a qcow image, 'windows.img', to a raw 'windows.raw' file , run

qemu-img convert windows.img -O raw windows.raw

Converting a raw drive to qcow format

To convert a raw 'windows.img' file to a qcow formatted 'windows.qcow', run

qemu-img convert windows.img -O qcow windows.qcow

Troubleshooting

If you experience problems with mouse pointer hanging in bottom right corner, try before you start up qemu

export SDL_VIDEO_X11_DGAMOUSE=0

If you experience the guest Windows XP hanging after the mouse is captured, try this option

-usb -usbdevice tablet

External Links

This has been tested by me and works in Ubuntu 7.10 Gutsy Gibbon. This has been tested by me and works in Ubuntu 8.04 Hardy Heron.