[libvirt] [PATCH RESEND RFC v4 0/6] support cpu bandwidth in libvirt

[Wen Congyang]

Resend this patchset

TODO:
1. We create sub directory for each vcpu in cpu subsystem. So
   we should recalculate cpu.shares for each vcpu.

Changelog:
v4: address Adam Litke's comment
v3: fix some small bugs
    implement the simple way
v2: almost rewrite the patchset to support to control each vcpu's
    bandwidth.
    Limit quota to [-1, 2^64/1000] at the schemas level. We will
    check it at cgroup level.

Wen Congyang (6):
  Introduce the function virCgroupForVcpu
  cgroup: Implement cpu.cfs_period_us and cpu.cfs_quota_us tuning API
  Update XML Schema for new entries
  qemu: Implement period and quota tunable XML configuration and
    parsing
  qemu: Implement cfs_period and cfs_quota's modification
  doc: Add documentation for new cputune elements period and quota

 docs/formatdomain.html.in                       |   19 ++
 docs/schemas/domain.rng                         |   26 ++-
 src/conf/domain_conf.c                          |   20 ++-
 src/conf/domain_conf.h                          |    2 +
 src/libvirt_private.syms                        |    5 +
 src/qemu/qemu_cgroup.c                          |  137 ++++++++++
 src/qemu/qemu_cgroup.h                          |    4 +
 src/qemu/qemu_driver.c                          |  312 +++++++++++++++++++++--
 src/qemu/qemu_process.c                         |    4 +
 src/util/cgroup.c                               |  153 +++++++++++-
 src/util/cgroup.h                               |   11 +
 tests/qemuxml2argvdata/qemuxml2argv-cputune.xml |    2 +
 12 files changed, 659 insertions(+), 36 deletions(-)