= How to share liblitmus with a virtual machine =

To make the userspace libraries of LITMUS^RT^ (liblitmus) available to the virtual machine in kvm , it is convenient to set up an NFS-server on the host to synchronize the libraries automatically.
I used a Debian system for my setup, but it should be easy to adapt the following instructions to other Linux distributions. On both the host and the client,  `/var/nfs` will be the shared directory.

First we install and configure nfs '''on the host''':
{{{
apt-get install nfs-kernel-server nfs-common portmap
mkdir /var/nfs
chown nobody:nogroup /var/nfs/
}}}

Enter into `/etc/exports`:
{{{
/var/nfs	localhost(rw,sync,no_subtree_check,all_squash,insecure,anonuid=1000)
}}}
Where ''1000'' is the userid for your user name. (View `/etc/passwd` for example)

Still on the host, we need to make sure that the NFS directory is shared and that your user account has access to it:
{{{
exportfs -a
usermod -aG nogroup $USER
chmod g+w /var/nfs
}}}
Again, you should substitute `$USER` with the right name.

To make the virtual machine able to use the network and NFS, we need to ensure that the desired features are enabled in the kernel configuration.
I had to add for internet connection:
 * CONFIG_NET_ETHERNET=y
 * CONFIG_NET_PCI=y
 * CONFIG_8139CP=y
and for NFS:
 * CONFIG_NETWORK_FILESYSTEMS=y
 * CONFIG_NFS_V4=y
then `make menuconfig` automatically adds:
 * CONFIG_NFS_FS=y
 * CONFIG_LOCKD=y
 * CONFIG_NFS_COMMON=y
 * CONFIG_SUNRPC=y
 * CONFIG_SUNRPC_GSS=y
 * CONFIG_RPCSEC_GSS_KRB5=y
 * CONFIG_KEYS=y
 * CONFIG_DNS_RESOLVER=y

Now you should start `kvm` with the following command to enable network connection (view also [[VirtualMachineImages|How to start kvm]]) :
{{{
kvm -smp 2 -m 512 -boot c -vga std -net nic -net user,hostfwd=tcp::10022-:22 -kernel path_to_kernel/arch/x86/boot/bzImage -append root=/dev/hda1 -hda kvm_image.img
}}}

'''On the client''' we also need some configurations:
{{{
mkdir /var/nfs
}}}

And we want to automatically mount the new network directory. Add the following entry to `/etc/fstab`:
{{{
10.0.2.2:/var/nfs	/var/nfs	nfs	defaults 0 0
}}}