This documentation is work in progress - more information needs to be added for different Linux distributions.
Linux is QEMU's main host platform. Therefore it is the platform which gets most support. Both 32 and 64 bit Linux hosts are supported. Most of the following instructions are valid for both variants.
Most Linux distributions already provide binary packages for QEMU (or KVM).
Usually they also include all packages which are needed to compile QEMU for Linux. The default installation of most distributions will not include everything, so you have to install some additional packages before you can build QEMU.
Fedora, Debian and Debian based or similar distributions normally include compiler and compilation tools (gcc, make, ...) in their default installation.
For Ubuntu LTS Trusty (and maybe other Debian based distributions), all required additional packages can be installed like this:
sudo apt-get install git libglib2.0-dev libfdt-dev libpixman-1-dev zlib1g-dev
For Red Hat Enterprise Linux 7 or CentOS 7 all required additional packages can be installed like this:
yum install git glib2-devel libfdt-devel pixman-devel zlib-devel
The above list is far from being complete. For maximum code coverage, as many QEMU features as possible should be enabled. When running configure, you should get many lines with "yes" and only a few with "no".
For Ubuntu Trusty (and maybe other Debian based distributions), all recommended additional packages for maximum code coverage can be installed like this:
sudo apt-get install git-email sudo apt-get install libaio-dev libbluetooth-dev libbrlapi-dev libbz2-dev sudo apt-get install libcap-dev libcap-ng-dev libcurl4-gnutls-dev libgtk-3-dev sudo apt-get install libibverbs-dev libjpeg8-dev libncurses5-dev libnuma-dev sudo apt-get install librbd-dev librdmacm-dev sudo apt-get install libsasl2-dev libsdl1.2-dev libseccomp-dev libsnappy-dev libssh2-1-dev sudo apt-get install libvde-dev libvdeplug-dev libvte-2.90-dev libxen-dev liblzo2-dev sudo apt-get install valgrind xfslibs-dev
Newer versions of Debian / Ubuntu might also try these additional packages:
sudo apt-get install libnfs-dev libiscsi-dev
Those packages also exist in Ubuntu Trusty, but they are too old for QEMU.
For Red Hat Enterprise Linux 7 or CentOS 7 some of the additional recommended packages can be installed like this:
sudo yum install libaio-devel libcap-devel libiscsi-devel
If you want the latest code, follow the development of the code, work with several versions or maybe even contribute to the code, you will need a local copy of the QEMU code repository which is managed using git.
Get the code like this:
git clone git://git.qemu-project.org/qemu.git
The resulting directory qemu is your QEMU root directory.
QEMU supports builds in this directory (not recommended) or in an extra directory (out-of-tree builds, recommended). There can be any number of out-of-tree builds, so if you plan to make cross builds, debug and release builds, out-of-tree builds are what you need.
Here is my typical build scenario:
# Switch to the QEMU root directory. cd qemu # Prepare a native debug build. mkdir -p bin/debug/native cd bin/debug/native # Configure QEMU and start the build. ../../../configure --enable-debug make # Return to the QEMU root directory. cd ../../..
Now let's start a simple test:
bin/debug/native/x86_64-softmmu/qemu-system-x86_64 -L pc-bios
This test runs the QEMU system emulation which boots a PC BIOS.
This example will show an in-tree build.
# Switch to the QEMU root directory cd qemu # Configure QEMU for x86_64 only - faster build ./configure --target-list=x86_64-softmmu --enable-debug # Build in parallel - my system has 4 CPUs make -j4
Getting ready to install a guest OS in a VM:
# Create a disk for the VM ./qemu-img create -f qcow2 test.qcow2 16G # Download an install ISO - I have Fedora 20 ls -la Fedora-Live-Desktop-x86_64-20-1.iso -rwxr-xr-x. 1 xxxxx xxxxx 999292928 May 4 16:32
Run QEMU with KVM enabled (w/o VNC):
If you have gtk2-devel installed, this will launch a simple UI and you can install your OS.
x86_64-softmmu/qemu-system-x86_64 -m 1024 -enable-kvm \ -drive if=virtio,file=test.qcow2,cache=none \ -cdrom Fedora-Live-Desktop-x86_64-20-1.iso
Run QEMU with KVM enabled (with VNC):
If you you prefer VNC, try this:
x86_64-softmmu/qemu-system-x86_64 -m 1024 -enable-kvm \ -drive if=virtio,file=test.qcow2,cache=none \ -cdrom Fedora-Live-Desktop-x86_64-20-1.iso \ -vnc :1
Connect using your favorite VNC viewer to localhost:1 and install your OS.
Cross building for non-native architectures is quite common. Hosts/W32 contains a description of cross building for Windows (32 and 64 bit) on Linux hosts. TODO: add more descriptions (32 bit Linux target on a 64 bit Linux host would be useful for build bots).
The QEMU build system supports compiling a git clone inside a docker container. With docker installed, for example, it can be started with "make docker-test-quick@ubuntu", to build x86_64-softmmu and aarch64-softmmu targets in a ubuntu instance.
See also Testing/DockerBuild for more information.
All QEMU system emulation should be working.
User mode emulation is also supported.