Re: [PATCH RFC 0/7] KVM: nVMX: enlightened VMCS initial implementation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 21/12/2017 13:50, Vitaly Kuznetsov wrote:
> I'm back with (somewhat frustrating) results (E5-2603):

v4 (that would be Broadwell)?

> 1) Windows on Hyper-V (no nesting): 1350 cycles
> 
> 2) Windows on Hyper-V on Hyper-V: 8600
> 
> 3) Windows on KVM (no nesting): 1150  cycles
> 
> 4) Windows on Hyper-V on KVM (no enlightened VMCS): 18200
> 
> 5) Windows on Hyper-V on KVM (enlightened VMCS): 17100

What version were you using for KVM?  There are quite a few nested virt
optimizations in kvm/queue (which may make enlightened VMCS both more or
less efficient).

In particular, with latest kvm/queue you could try tracing vmread and
vmwrite vmexits, and see if you get any.  If you do, that might be an
easy few hundred cycles savings.

Paolo
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel



[Index of Archives]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux