Re: [libvirt] [PATCH 2/3] qemu_driver: clamp value for setting sched cpu_shares with --config.

As shown in 'man virsh' about schedinfo: Note: The cpu_shares parameter has a valid value range of 0-262144; Negative values are wrapped to positive, and larger values are capped at the maximum. Therefore, -1 is a useful shorthand for 262144. On the Linux kernel, the values 0 and 1 are automatically converted to a minimal value of 2. it works well with --live, but not with --config. Example: # virsh schedinfo rhel7-ful --set cpu_shares=0 --config Scheduler : posix cpu_shares : 0 vcpu_period : 0 vcpu_quota : 0 emulator_period: 0 emulator_quota : 0 cpu_shares is 0 rather than expected 2. What's worse, when we start it again, it is the default value of cpu_shares 1024. Because when we set the value of cpu_shares, when flag is --live, write the value into cgroup/cpu.shares. Then it will convert the value into the range of [2, 262144]. When flag is --config, we set the value into vmdef immidiately and 0 means no settting for cpu_shares. When we start vm again, libvirt use default value(1024) for it.