profiling netperf on KVM using perf tool

** experimental setting **
- 192.168.1.1: host OS
- 192.168.1.10: guest OS
- 192.168.1.2: remote machine's OS

** sender side **
192.168.1.10$ netperf -H 192.168.1.2 -c -C -l 70
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.1.2 (192.168.1.2) port 0 AF_INET : demo
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  65536  65536    70.00      2099.76   99.43    0.08     3.879   0.024

192.168.1.1$ sudo ./perf stat -e 'kvm:*' -a sleep 1m

 Performance counter stats for 'sleep 1m':

        1319133  kvm:kvm_entry           
              0  kvm:kvm_hypercall       
              0  kvm:kvm_hv_hypercall    
         108579  kvm:kvm_pio             
              0  kvm:kvm_cpuid           
         295147  kvm:kvm_apic            
        1319126  kvm:kvm_exit            
         290013  kvm:kvm_inj_virq        
         564035  kvm:kvm_page_fault      
              0  kvm:kvm_msr             
              6  kvm:kvm_cr              
              0  kvm:kvm_pic_set_irq     
              0  kvm:kvm_apic_ipi        
         404436  kvm:kvm_apic_accept_irq 
              0  kvm:kvm_nested_vmrun    
              0  kvm:kvm_nested_vmexit   
              0  kvm:kvm_nested_vmexit_inject
              0  kvm:kvm_nested_intr_vmexit
              0  kvm:kvm_invlpga         
              0  kvm:kvm_skinit          
         398435  kvm:kvm_set_irq         
              0  kvm:kvm_ioapic_set_irq  
         398435  kvm:kvm_msi_set_irq     
              0  kvm:kvm_ack_irq         
         666601  kvm:kvm_mmio            
              2  kvm:kvm_fpu             
              0  kvm:kvm_age_page        

   60.001032540  seconds time elapsed

** receiver side **

192.168.1.2$ netperf -H 192.168.1.10 -c -C -l 70 
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.1.10 (192.168.1.10) port 0 AF_INET : demo
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    70.02      2774.22   2.23     96.39    0.526   2.846 


192.168.1.1$ sudo ./perf stat -e 'kvm:*' -a sleep 1m

 Performance counter stats for 'sleep 1m':


        1705898  kvm:kvm_entry           
              0  kvm:kvm_hypercall       
              0  kvm:kvm_hv_hypercall    
          42412  kvm:kvm_pio             
              0  kvm:kvm_cpuid           
         770209  kvm:kvm_apic            
        1705910  kvm:kvm_exit            
         760014  kvm:kvm_inj_virq        
          67336  kvm:kvm_page_fault      
              0  kvm:kvm_msr             
           1504  kvm:kvm_cr              
              0  kvm:kvm_pic_set_irq     
              0  kvm:kvm_apic_ipi        
        1577114  kvm:kvm_apic_accept_irq 
              0  kvm:kvm_nested_vmrun    
              0  kvm:kvm_nested_vmexit   
              0  kvm:kvm_nested_vmexit_inject
              0  kvm:kvm_nested_intr_vmexit
              0  kvm:kvm_invlpga         
              0  kvm:kvm_skinit          
        1571245  kvm:kvm_set_irq         
              0  kvm:kvm_ioapic_set_irq  
        1571245  kvm:kvm_msi_set_irq     
              0  kvm:kvm_ack_irq         
         863830  kvm:kvm_mmio            
          60668  kvm:kvm_fpu             
              0  kvm:kvm_age_page        

   60.000938690  seconds time elapsed