[PATCH v2 RESEND 00/17] Introduce RDT memory bandwidth allocation support

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From: Bing Niu <bing.niu@xxxxxxxxx>

This series is to introduce RDT memory bandwidth allocation support by extending
current virresctrl implementation.

The Memory Bandwidth Allocation (MBA) feature provides indirect and approximate
control over memory bandwidth available per-core. This feature provides a method to
control applications which may be over-utilizing bandwidth relative to their priority
in environments such as the data-center. The details can be found in Intel's SDM 17.19.7.
Kernel supports MBA through resctrl file system same as CAT. Each resctrl group have a
MB parameter to control how much memory bandwidth it can utilize in unit of percentage.

In this series, MBA is enabled by enhancing existing virresctrl implementation. The
policy employed for MBA is similar with CAT: The sum of each MBA group's bandwidth
dose not exceed 100%.

The enhancement of virresctrl include two main parts:

Part 1:  Add two new structures virResctrlInfoMemMB and virResctrlAllocMemBW for collecting
         host system MBA capability and domain memory bandwidth allocation. Those two
         structures are the extension of existing virResctrlInfo and virResctrlAlloc. With
         them, virresctrl framework can support MBA and CAT concurrently. Each virResctrlAlloc
         represent a resource allocation including CAT, or MBA, or CAT&MBA. The policy of MBA is
         that: total memory bandwidth of each resctrl group, created by virresctrl, does not
         exceed to 100%.

Part 2:  On XML part, add new elements to host capabilities query and domain allocation to support
         memory bandwidth allocation.
     ---------------------------------------------------------------------------------------------
         For host capabilities XML, new XML format like below example,
           <host>
            .....
             <memory_bandwidth>
               <node id='0' cpus='0-19'>
                 <control granularity='10' min ='10' maxAllocs='8'/>
               </node>
             </memory_bandwidth>
           </host>

           granularity --- memory bandwidth granularity
           min         --- minimum memory bandwidth allowed
           maxAllocs   --- maximum concurrent memory bandwidth allocation allowed.

     ---------------------------------------------------------------------------------------------
         For domain XML, new format as below example
           <domain type='kvm' id='2'>
             ......
             <cputune>
               ......
               <shares>1024</shares>
               <memorytune vcpus='0-1'>
                 <node id='0' bandwidth='20'/>
               </memorytune>
             </cputune>
             ......
           </domain>

          id         --- node where memory bandwidth allocation will happen
          bandwidth  --- bandwidth allocated in percentage

     ----------------------------------------------------------------------------------------------

With this extension of the virresctrl, the overall working follow of CAT and MBA is described by below
picture. XML parser will aggregate MBA and CAT configuration and represents it in one virresctrl object.
The methods of virresctrl class will manipulate resctrl interface to allocate corresponding resources.


     <memorytune cpus='0-3'>
                    +---------+
                              |    <cachetune vcpus='0-3'>
        XML                   |           +
       parser                 +-----------+
                              |
                              |
                 +------------------------------+
                              |
                              |
internal object        +------v--------------+  
virResctrlAlloc        |   backing object    |
                       +------+--------------+
                              |
                              |
                 +------------------------------+
                              |
                           +--v-------+
                           |          |
                           | schemata |
 /sys/fs/resctrl           | tasks    |
                           |   .      |
                           |   .      |
                           |          |
                           +----------+
---------------------------------------------------------------------

previous versions and discussion can be found at
    v1: https://www.redhat.com/archives/libvir-list/2018-July/msg01144.html
RFC v2: https://www.redhat.com/archives/libvir-list/2018-June/msg01268.html
RFC v1: https://www.redhat.com/archives/libvir-list/2018-May/msg02101.html

Changelog:
       v1 -> this: John's comment: 1. Split calculation of number of memory bandwidth control
                                      to one patch.
                                   2. Split virResctrlAllocMemBW relating methods to 5 patch, each
                                      provides one kind of function, eg: schemata processing, memory
                                      bandwidth calculation.....
                                   3. Use resctrl to replace cachetune in domain conf.
                                   4. Split refactor virDomainCachetuneDefParse into 3 patches. And
                                      adjust some logic, eg: use %s format error log, renaming
                                      functions.....
                                   5. Complete doc description. eg: update cachetune part about vcpus
                                      overlapping with memorytune, update libvirt version info for memory
                                      bandwidth control availability.
                                   6. Some coding style fix.

       RFC_v2->v1: John's comment: 1. use name MemBW to replace MB for a more clear description.
                                   2. split rename patch and put refactor function part separately.
                                   3. split virResctrlInfoMemMB and virResctrlAllocMemBW to different
                                      patches.
                                   4. add docs/schemas/*.rng for XML related patches.
                                   5. some cleanup for coding conventions.
       RFC_ v1->RFC_v2:
            Jano's comment: 1. put renaming parts into separated patches.
                            2. set the initial return value as -1.
                            3. using full name in structure definition.
                            4. do not use VIR_CACHE_TYPE_LAST for memory bandwidth allocation formatting.

            Pavel's comment: 1. add host capabilities XML for memory bandwidth allocation.
                             2. do not mix use cachetune section in XML for memory bandwidth allocation in
                                domain XML. define a dedicated one for memory bandwidth allocation.

Bing Niu (17):
  util: Rename some functions of virresctrl
  util: Refactor virResctrlGetInfo in virresctrl
  util: Refactor virResctrlAllocFormat of virresctrl
  util: Add MBA capability information query to resctrl
  util: Add MBA check to virResctrlInfoGetCache
  util: Add MBA allocation to virresctrl
  util: Add MBA schemata parse and format methods
  util: Add support to calculate MBA utilization
  util: Introduce virResctrlAllocForeachMemory
  util: Introduce virResctrlAllocSetMemoryBandwidth
  conf: Rename cachetune to resctrl
  conf: Factor out vcpus parsing part from virDomainCachetuneDefParse
  conf: Factor out vcpus overlapping from virDomainCachetuneDefParse
  conf: Factor out virDomainResctrlDef update from
    virDomainCachetuneDefParse
  conf: Add support for memorytune XML processing for resctrl MBA
  conf: Add return value check to virResctrlAllocForeachCache
  conf: Add memory bandwidth allocation capability of host

 docs/formatdomain.html.in                          |  39 +-
 docs/schemas/capability.rng                        |  33 ++
 docs/schemas/domaincommon.rng                      |  17 +
 src/conf/capabilities.c                            | 107 ++++
 src/conf/capabilities.h                            |  11 +
 src/conf/domain_conf.c                             | 428 ++++++++++++---
 src/conf/domain_conf.h                             |  10 +-
 src/libvirt_private.syms                           |   6 +-
 src/qemu/qemu_domain.c                             |   2 +-
 src/qemu/qemu_process.c                            |  18 +-
 src/util/virresctrl.c                              | 611 +++++++++++++++++++--
 src/util/virresctrl.h                              |  55 +-
 .../memorytune-colliding-allocs.xml                |  30 +
 .../memorytune-colliding-cachetune.xml             |  32 ++
 tests/genericxml2xmlindata/memorytune.xml          |  33 ++
 tests/genericxml2xmltest.c                         |   5 +
 .../linux-resctrl/resctrl/info/MB/bandwidth_gran   |   1 +
 .../linux-resctrl/resctrl/info/MB/min_bandwidth    |   1 +
 .../linux-resctrl/resctrl/info/MB/num_closids      |   1 +
 tests/vircaps2xmldata/vircaps-x86_64-resctrl.xml   |   8 +
 tests/virresctrldata/resctrl.schemata              |   1 +
 21 files changed, 1280 insertions(+), 169 deletions(-)
 create mode 100644 tests/genericxml2xmlindata/memorytune-colliding-allocs.xml
 create mode 100644 tests/genericxml2xmlindata/memorytune-colliding-cachetune.xml
 create mode 100644 tests/genericxml2xmlindata/memorytune.xml
 create mode 100644 tests/vircaps2xmldata/linux-resctrl/resctrl/info/MB/bandwidth_gran
 create mode 100644 tests/vircaps2xmldata/linux-resctrl/resctrl/info/MB/min_bandwidth
 create mode 100644 tests/vircaps2xmldata/linux-resctrl/resctrl/info/MB/num_closids

-- 
2.7.4

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