mirror of
https://github.com/libvirt/libvirt.git
synced 2025-02-25 18:55:26 -06:00
7c6fc3948e
Now that we track a disk mirror as a virStorageSource, we might as well update the XML to theoretically allow any type of mirroring destination (not just a local file). A later patch will also be reusing <mirror> to track the block commit of the top layer of a chain, which is another case where libvirt needs to update the backing chain after the job is finally pivoted, and since backing chains can have network backing files as the destination to commit into, it makes more sense to display that in the XML. This patch changes output-only XML; it was already documented that <mirror> does not affect a domain definition at this point (because qemu doesn't provide persistent bitmaps yet). Any application that was starting a block copy job with older libvirt and then relying on the domain XML to determine if it was complete will no longer be able to access the file= and format= attributes of mirror that were previously used. However, this is not going to be a problem in practice: the only time a block copy job works is on a transient domain, and any app that is managing a transient domain probably already does enough of its own bookkeeping to know which file it is mirroring into without having to re-read it from the libvirt XML. The one thing that was likely to be used in a mirroring job was the ready= attribute, which is unchanged. Meanwhile, I made sure the schema and parser still accept the old format, even if we no longer output it, so that upgrading from an older version of libvirt is seamless. * docs/schemas/domaincommon.rng (diskMirror): Alter definition. * src/conf/domain_conf.c (virDomainDiskDefParseXML): Parse two styles of mirror elements. (virDomainDiskDefFormat): Output new style. * tests/qemuxml2argvdata/qemuxml2argv-disk-mirror-old.xml: New file, copied from... * tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: ...here before modernizing. * tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-mirror-old*: New files. * tests/qemuxml2xmltest.c (mymain): Test both styles. Signed-off-by: Eric Blake <eblake@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
* phyp/ - IBM Power Hypervisor using CLI tools over SSH
* qemu/ - QEMU / KVM using qemu CLI/monitor
* remote/ - Generic libvirt native RPC client
* test/ - A "mock" driver for testing
* uml/ - User Mode Linux
* vbox/ - Virtual Box using native API
* vmware/ - VMware Workstation and Player using the vmrun tool
* xen/ - Xen using hypercalls, XenD SEXPR & XenStore
* xenapi/ - Xen using libxenserver
Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU, UML and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, 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