same core need to be enabled as well. All non-hotpluggable CPUs present at
boot need to be grouped after vCPU 0. :since:`Since 2.2.0 (QEMU only)`
-:anchor:`<a id="elementsIOThreadsAllocation"/>`
IOThreads Allocation
--------------------
of element ``vcpu`` is not specified, the IOThreads are pinned to all the
physical CPUs by default. There are two required attributes, the attribute
``iothread`` specifies the IOThread ID and the attribute ``cpuset``
- specifying which physical CPUs to pin to. See the ``iothreadids``
- `description <#elementsIOThreadsAllocation>`__ for valid ``iothread`` values.
- :since:`Since 1.2.9`
+ specifying which physical CPUs to pin to. See the `IOThreads Allocation`_
+ section documenting valid values of ``iothread``. :since:`Since 1.2.9`
``shares``
The optional ``shares`` element specifies the proportional weighted share for
the domain. If this is omitted, it defaults to the OS provided defaults. NB,
vCPUs/IOThreads this setting applies to, leaving them out sets the default.
The element ``emulatorsched`` does not have that attribute. Valid ``vcpus``
values start at 0 through one less than the number of vCPU's defined for the
- domain. Valid ``iothreads`` values are described in the ``iothreadids``
- `description <#elementsIOThreadsAllocation>`__. If no ``iothreadids`` are
+ domain. Valid ``iothreads`` values are described in the `IOThreads Allocation`_
+ section. If no ``iothreadids`` are
defined, then libvirt numbers IOThreads from 1 to the number of ``iothreads``
available for the domain. For real-time schedulers (``fifo``, ``rr``),
priority must be specified as well (and is ignored for non-real-time ones).
intensive operation, but can save file space and/or time on slow media.
:since:`Since 2.0.0`
- The optional ``iothread`` attribute assigns the disk to an IOThread as
- defined by the range for the domain
- `iothreads <#elementsIOThreadsAllocation>`__ value. Multiple disks may be
+ defined by the range for the domain ``iothreads`` value. (See
+ `IOThreads Allocation`_). Multiple disks may be
assigned to the same IOThread and are numbered from 1 to the domain
iothreads value. Available for a disk device ``target`` configured to use
"virtio" ``bus`` and "pci" or "ccw" ``address`` types. :since:`Since 1.2.8
Supported for controller type ``scsi`` using model ``virtio-scsi`` for
``address`` types ``pci`` and ``ccw`` :since:`since 1.3.5 (QEMU 2.4)` . The
optional ``iothread`` attribute assigns the controller to an IOThread as
- defined by the range for the domain
- `iothreads <#elementsIOThreadsAllocation>`__ value. Each SCSI ``disk``
+ defined by the range for the domain ``iothreads`` (See `IOThreads Allocation`_).
+ Each SCSI ``disk``
assigned to use the specified ``controller`` will utilize the same IOThread.
If a specific IOThread is desired for a specific SCSI ``disk``, then multiple
controllers must be defined each having a specific ``iothread`` value. The