Re: How to enable Pause Loop Exiting (PLE)?

["Zhang Haoyu" <zhanghy@sangfor.com>]

>>>Hi,
>>>
>>>I am using this tool for querying VMX capabilities.
>>>
>>>http://git.qemu.org/?p=qemu.git;a=blob_plain;f=scripts/kvm/vmxcap;hb=HEAD
>>>
>>>And it shows as below that pause-loop exiting is not enabled. My kernel is 3.14.
>>>
>>>secondary processor-based controls
>>>  Virtualize APIC accesses                 yes
>>>  Enable EPT                               yes
>>>  Descriptor-table exiting                 yes
>>>  Enable RDTSCP                            yes
>>>  Virtualize x2APIC mode                   yes
>>>  Enable VPID                              yes
>>>  WBINVD exiting                           yes
>>>  Unrestricted guest                       no
>>>  APIC register emulation                  no
>>>  Virtual interrupt delivery               no
>>>  PAUSE-loop exiting                       no
>>>  RDRAND exiting                           no
>>>  Enable INVPCID                           no
>>>  Enable VM functions                      no
>>>  VMCS shadowing                           no
>>>  EPT-violation #VE                        no
>>>
>>>What shall I do if I wish to enable PLE? I have also tried this:
>>>
>> From above info, your physical cpu dose not support ple feature,
>> if you want to enable ple, your cpu must support ple feature, and 'PAUSE exiting' must be 0-settting, 'PAUSE-loop exiting' must be 1-setting.
>> And, kvm-intel module will enable ple as default if your cpu support ple feature.
>>
>Hi, Haoyu,
>
>I have another machine, in which Pause Loop Exiting is showing yes,
>but PAUSE Exiting is also showing yes, see below, but you said PAUSE
>exiting must be 0 setting, so what shall I do? Is PLE enabled or not?
>
check /sys/module/kvm_intel/parameters/ple_gap, if non-zero(>0), ple is enabled, zero means ple is disabled.

Thanks,
Zhang Haoyu
>primary processor-based controls
>  Interrupt window exiting                 yes
>  Use TSC offsetting                       yes
>  HLT exiting                              yes
>  INVLPG exiting                           yes
>  MWAIT exiting                            yes
>  RDPMC exiting                            yes
>  RDTSC exiting                            yes
>  CR3-load exiting                         default
>  CR3-store exiting                        default
>  CR8-load exiting                         yes
>   CR8-store exiting                        yes
>  Use TPR shadow                           yes
>  NMI-window exiting                       yes
>  MOV-DR exiting                           yes
>  Unconditional I/O exiting                yes
>  Use I/O bitmaps                          yes
>  Monitor trap flag                        yes
>  Use MSR bitmaps                          yes
>  MONITOR exiting                          yes
>  PAUSE exiting                            yes
>  Activate secondary control               yes
>secondary processor-based controls
>  Virtualize APIC accesses                 yes
>  Enable EPT                               yes
>  Descriptor-table exiting                 yes
>  Enable RDTSCP                            yes
>  Virtualize x2APIC mode                   yes
>  Enable VPID                              yes
>  WBINVD exiting                           yes
>  Unrestricted guest                       yes
>  APIC register emulation                  no
>  Virtual interrupt delivery               no
>  PAUSE-loop exiting                       yes
>  RDRAND exiting                           no
>  Enable INVPCID                           no
>  Enable VM functions                      no
>  VMCS shadowing                           no
>  EPT-violation #VE                        no