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This is a quite an old (created at 2016) patch fixing an issue for at that time contemporary Fedora 23. virsh reboot returns success (yet after hanging for a while), VM is rebooted sucessfully too but then shutdown from inside guest causes reboot and not shutdown. VM has agent installed. So virsh reboot first tries to reboot VM thru the agent. The agent calls 'shutdown -r' command. Typically it returns instantly but on this distro for some reason it takes time. I did not investigate the cause but the command waits in dbus client code, probably waits for reply. The libvirt waits 60s for agent command to execute and then errors out. Next reboot API falls back to ACPI shutdown which returns successfully thus the reboot command return success too. Yet shutdown command in guest eventually successfull and guest is truly rebooted. So libvirt does not receive SHUTDOWN event and fake reboot flag which is armed on fallback path stays armed. Thus next shutdown from guest leads to reboot. The issue has 100% repro on Fedora 23. On modern distros I can't reproduce it at all. Shutdown command is asynchronous and returns immediately even if I start some service that ignores TERM signal and thus shutdown procedure waits for 90s (if I not mistaken) before sending KILL. Yet I guess it is nice to have this patch to be more robust. Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Nikolay Shirokovskiy <nikolay.shirokovskiy@openvz.org>
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