8abd1ffed1
In 6.7.0 release I've changed how domain namespace is built and populated. Previously it used to be done from a pre-exec hook (ran in the forked off child, just before dropping all privileges and exec()-ing QEMU), which not only meant we had to have two different code paths for creating a node in domain's namespace (one for this pre-exec hook, the other for hotplug ran from the daemon), it also proved problematic because it was leaking FDs into QEMU process. To mitigate this problem, we've not only ditched libdevmapper from the NS population process, I've also dropped the pre-exec code and let the NS be populated from the daemon (using the hotplug code). But, I was not careful when doing so, because the pre-exec code was tolerant to files that doesn't exist, while this new code isn't. For instance, the very first thing that is done when the new NS is created is it's populated with @defaultDeviceACL which contain files like /dev/null, /dev/zero, /dev/random and /dev/kvm (and others). While the rest will probably exist every time, /dev/kvm might not and thus the new code I wrote has to be tolerant to that. Of course, users can override the @defaultDeviceACL (by setting cgroup_device_acl in qemu.conf) and remove /dev/kvm (which is acceptable workaround), but we definitely want libvirt to work out of the box even on hosts without KVM. Fixes: 9048dc4e627ddf33996084167bece7b5fb83b0bc Reported-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser
General Public License, version 2.1 (or later). Some parts of the code
that are not part of the C library may have the more restrictive GNU
General Public License, version 2.0 (or later). See the files
COPYING.LESSER and COPYING for full license
terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: