Re: [PATCH v5 02/18] schema: Add new domain elements to support multiple throttle filters

From: Chun Feng Wu <danielwuwy(a)163.com&gt; Introduce schema for defining '<throttlefilters>' element which references throttling groups to form filter chain in qemu for specific disk * Add new elements '<throttlefilters>' * <ThrottleFilters> can include multiple throttlegroup references to form filter chain in qemu * Chained throttle filters feature in qemu is described at https://github.com/qemu/qemu/blob/master/docs/throttle.txt

Signed-off-by: Chun Feng Wu <danielwuwy(a)163.com&gt; --- docs/formatdomain.rst | 21 +++++++++++++++++++++ src/conf/schemas/domaincommon.rng | 19 ++++++++++++++++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index 5b7f18b2f0..0c41b47a77 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -2753,6 +2753,15 @@ paravirtualized driver is specified via the ``disk`` element. <source dev='/dev/vhost-vdpa-0' /> <target dev='vdg' bus='virtio'/> </disk> + <disk type='file' device='disk'> + <driver name='qemu' type='qcow2' /> + <source file='/var/lib/libvirt/images/disk.qcow2'/> + <target dev='vdh' bus='virtio'/>

+ <throttlefilters> + <throttlefilter group='limit2'/> + <throttlefilter group='limit012'/> + </throttlefilters> + </disk> </devices> ... @@ -3233,6 +3242,18 @@ paravirtualized driver is specified via the ``disk`` element. :since:`since after 0.4.4`; "sata" attribute value :since:`since 0.9.7`; "removable" attribute value :since:`since 1.1.3`; "rotation_rate" attribute value :since:`since 7.3.0` +``throttlefilters`` + The optional ``throttlefilters`` element provides the ability to provide additional + per-device throttle chain :since:`Since 10.7.0`

+ For example, if we have four different disks and we want to limit I/O for each one + and we also want to limit combined I/O of all four disks, we can leverage + ``throttlefilters`` to achieve this goal by setting two ``throttlefilter`` for + each disk: disk's own filter(e.g. limit2) and combined filter(e.g. limit012). + The order of such ``throttlefilter`` doesn't matter within ``throttlefilters``. + ``throttlefilters`` and ``iotune`` should be used exclusively. + + ``throttlefilter`` + The optional ``throttlefilter`` element is to reference defined throttle group. ``iotune`` The optional ``iotune`` element provides the ability to provide additional per-device I/O tuning, with values that can vary for each device (contrast