mirror of
https://github.com/gnif/LookingGlass.git
synced 2024-11-10 08:38:20 +00:00
161 lines
4.3 KiB
ReStructuredText
161 lines
4.3 KiB
ReStructuredText
Kernel Module
|
|
#############
|
|
|
|
This kernel module implements a basic interface to the IVSHMEM device
|
|
for LookingGlass when using LookingGlass in VM->VM mode.
|
|
|
|
Additionally, in VM->host mode, it can be used to generate a shared
|
|
memory device on the host machine that supports dmabuf.
|
|
|
|
Compiling (Manual)
|
|
------------------
|
|
|
|
Make sure you have your kernel headers installed first, on Debian/Ubuntu
|
|
use the following command::
|
|
|
|
apt-get install linux-headers-$(uname -r)
|
|
|
|
Then simply run ``make`` and you're done.
|
|
|
|
Loading
|
|
~~~~~~~
|
|
|
|
For VM->VM mode, simply run::
|
|
|
|
insmod kvmfr.ko
|
|
|
|
For VM->host mode with dmabuf, instead of creating a shared memory file,
|
|
load this module with the parameter ``static_size_mb``. For example, a
|
|
128 MB shared memory device can be created with::
|
|
|
|
insmod kvmfr.ko static_size_mb=128
|
|
|
|
Multiple devices can be created by separating the sizes with commas. For
|
|
example, ``static_size_mb=128,64`` would create two kvmfr devices:
|
|
``kvmfr0`` would be 128 MB and ``kvmfr1`` would be 64 MB.
|
|
|
|
.. _compiling--installing-dkms:
|
|
|
|
Compiling & Installing (DKMS)
|
|
-----------------------------
|
|
|
|
You can install this module into DKMS so that it persists across kernel
|
|
upgrades. Simply run::
|
|
|
|
dkms install .
|
|
|
|
.. _loading-1:
|
|
|
|
Loading
|
|
~~~~~~~
|
|
|
|
For VM->VM, simply modprobe the module::
|
|
|
|
modprobe kvmfr
|
|
|
|
For VM->host with dmabuf, modprobe with the parameter
|
|
``static_size_mb``::
|
|
|
|
modprobe kvmfr static_size_mb=128
|
|
|
|
Just like above, multiple devices can be created by separating the sizes
|
|
with commas.
|
|
|
|
Usage
|
|
-----
|
|
|
|
This will create the ``/dev/kvmfr0`` node that represents the KVMFR
|
|
interface. To use the interface you need permission to access it by
|
|
either creating a udev rule to ensure your user can read and write to
|
|
it, or simply change its ownership manually, ie::
|
|
|
|
sudo chown user:user /dev/kvmfr0
|
|
|
|
An example udev rule, which you can put in
|
|
``/etc/udev/rules.d/99-kvmfr.rules``, is (replace ``user`` with your
|
|
username)::
|
|
|
|
SUBSYSTEM=="kvmfr", OWNER="user", GROUP="kvm", MODE="0660"
|
|
|
|
Usage with looking glass is simple, you only need to specify the path to
|
|
the device node, for example::
|
|
|
|
./looking-glass-client -f /dev/kvmfr0
|
|
|
|
You may also use a config file: ``~/.looking-glass-client.ini``, or
|
|
``/etc/looking-glass-client.ini``.
|
|
|
|
.. code:: ini
|
|
|
|
[app]
|
|
shmFile=/dev/kvmfr0
|
|
|
|
VM->Host
|
|
~~~~~~~~
|
|
|
|
In VM->host mode, use this device in place of the shared memory file.
|
|
|
|
For example, with ``qemu``, you would use the following arguments::
|
|
|
|
-device ivshmem-plain,id=shmem0,memdev=looking-glass
|
|
-object memory-backend-file,id=looking-glass,mem-path=/dev/kvmfr0,size=128M,share=yes
|
|
|
|
Note that the ``size`` argument must be the same size as what you passed
|
|
to ``static_size_mb`` argument for the kernel module.
|
|
|
|
``libvirt``
|
|
^^^^^^^^^^^
|
|
|
|
With ``libvirt``, you can use the following XML block:
|
|
|
|
.. code:: xml
|
|
|
|
<qemu:commandline>
|
|
<qemu:arg value='-device'/>
|
|
<qemu:arg value='ivshmem-plain,id=shmem0,memdev=looking-glass'/>
|
|
<qemu:arg value='-object'/>
|
|
<qemu:arg value='memory-backend-file,id=looking-glass,mem-path=/dev/kvmfr0,size=128M,share=yes'/>
|
|
</qemu:commandline>
|
|
|
|
Remember to add
|
|
``xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'`` to the
|
|
``<domain>``.
|
|
|
|
On certain distros, running libvirt this way poses issues with apparmor
|
|
and cgroups.
|
|
|
|
For apparmor, create ``/etc/apparmor.d/local/abstractions/libvirt-qemu`` if
|
|
it doesn't exist, and add the following::
|
|
|
|
# Looking Glass
|
|
/dev/kvmfr0 rw,
|
|
|
|
For cgroups, in ``/etc/libvirt/qemu.conf``, uncomment the
|
|
``cgroup_device_acl`` block and add ``/dev/kvmfr0`` to the list. Then
|
|
restart ``libvirtd``::
|
|
|
|
sudo systemctl restart libvirtd.service
|
|
|
|
.. _systemd_modules_load:
|
|
|
|
systemd-modules-load
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
For convenience, you may load the KVMFR module when starting your computer.
|
|
We can use the ``systemd-modules-load.service(8)`` service for this task.
|
|
|
|
Create a file as ``/etc/modules-load.d/kvmfr.conf`` with the following
|
|
contents::
|
|
|
|
#KVMFR Looking Glass module
|
|
kvmfr
|
|
|
|
This will now run the next time you start your machine.
|
|
|
|
If you are running in VM->host mode, you must additionally add another file in
|
|
``/etc/modprobe.d/kvmfr.conf`` to properly set the size. It should have the
|
|
following contents, while adjusting ``static_size_mb`` to your needs::
|
|
|
|
#KVMFR Looking Glass module
|
|
options kvmfr static_size_mb=128
|