Re: Host latency peaks due to kvm-intel

["Yang, Sheng" <sheng.yang@intel.com>]

On Monday 27 July 2009 03:16:27 H. Peter Anvin wrote:
> Jan Kiszka wrote:
> > Avi Kivity wrote:
> >> On 07/24/2009 12:41 PM, Jan Kiszka wrote:
> >>> I vaguely recall that someone promised to add a feature reporting
> >>> facility for all those nice things, modern VM-extensions may or may not
> >>> support (something like or even an extension of /proc/cpuinfo). What is
> >>> the state of this plan? Would be specifically interesting for Intel
> >>> CPUs as there seem to be many of them out there with restrictions for
> >>> special use cases - like real-time.
> >>
> >> Newer kernels do report some vmx features (like flexpriority) in
> >> /proc/cpuinfo but not all.
> >
> > Ah, nice. Then we just need this?
>
> Fine with me.
>
> Acked-by: H. Peter Anvin <hpa@zytor.com>
>
> However, I guess the real question if we shouldn't export ALL VMX
> features in a consistent way instead?
>
When I add feature reporting to cpuinfo, I just put highlight features there, 
otherwise the VMX feature list would at least as long as CPU one.

I have also suggested another field for virtualization feature for it, but 
some concern again userspace tools raised.

For we got indeed quite a lot features, and would get more, would it better to 
export the part of struct vmcs_config entries(that's pin_based_exec_ctrl, 
cpu_based_exec_ctrl, and cpu_based_2nd_exec_ctrl) through 
sys/module/kvm_intel/? Put every feature to cpuinfo seems not that necessary 
for such a big list.

-- 
regards
Yang, Sheng