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

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(-)