mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2025-01-24 21:45:21 +00:00
de3289e2b5
There was one attempt a year ago done by me to drop HAL [1] but it was never resolved. There was another time when Dan suggested to drop HAL driver [2] but it was decided to keep it around in case device assignment will be implemented for FreeBSD and the fact that virt-manager uses node device driver [3]. I checked git history and code and it doesn't look like bhyve supports device assignment so from that POV it should not block removing HAL. The argument about virt-manager is not strong as well because libvirt installed from FreeBSD packages doesn't have HAL support so it will not affect these users as well [4]. The only users affected by this change would be the ones compiling libvirt from GIT on FreeBSD. I looked into alternatives and there is libudev-devd package on FreeBSD but unfortunately it doesn't work as it doesn't list any devices when used with libvirt. It provides libudev APIs using devd. I also looked into devd directly and it provides some APIs but there are no APIs for device monitoring and events so that would have to be somehow done by libvirt. Main motivation for dropping HAL support is to replace libdbus with GLib dbus implementation and it cannot be done with HAL driver present in libvirt because HAL APIs heavily depends on symbols provided by libdbus. [1] <https://www.redhat.com/archives/libvir-list/2019-May/msg00203.html> [2] <https://www.redhat.com/archives/libvir-list/2016-April/msg00992.html> [3] <https://www.redhat.com/archives/libvir-list/2016-April/msg00994.html> [4] <https://svnweb.freebsd.org/ports/head/devel/libvirt/Makefile?view=markup> Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
libvirt library code README
===========================
The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.
The files directly in this directory are supporting the public API
entry points & data structures.
There are two core shared modules to be aware of:
* util/ - a collection of shared APIs that can be used by any
code. This directory is always in the include path
for all things built
* conf/ - APIs for parsing / manipulating all the official XML
files used by the public API. This directory is only
in the include path for driver implementation modules
* vmx/ - VMware VMX config handling (used by esx/ and vmware/)
Then there are the hypervisor implementations:
* bhyve - bhyve - The BSD Hypervisor
* esx/ - VMware ESX and GSX support using vSphere API over SOAP
* hyperv/ - Microsoft Hyper-V support using WinRM
* lxc/ - Linux Native Containers
* openvz/ - OpenVZ containers using cli tools
* qemu/ - QEMU / KVM using qemu CLI/monitor
* remote/ - Generic libvirt native RPC client
* test/ - A "mock" driver for testing
* vbox/ - Virtual Box using native API
* vmware/ - VMware Workstation and Player using the vmrun tool
* xen/ - Xen using hypercalls, XenD SEXPR & XenStore
Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU and Xen drivers.
The ESX, Hyper-V, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly
* cpu/ - CPU feature management
* interface/ - Host network interface management
* network/ - Virtual NAT networking
* nwfilter/ - Network traffic filtering rules
* node_device/ - Host device enumeration
* secret/ - Secret management
* security/ - Mandatory access control drivers
* storage/ - Storage management drivers
Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories