`-enable-kvm -cpu SandyBridge` instead of `-cpu qemu64`. Due to a bug in KVM,
QEMU or Linux, RAPL must be disabled to prevent a NULL deref:
gdb -batch -ex 'target remote localhost:1234' -ex 'break rapl_pmu_init' -ex c -ex return -ex c ./vmlinux
(speed improvement probably due to avx and xsave)
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx rdtscp lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx hypervisor lahf_lm xsaveopt
Sat, 22 Mar 2014 10:43:29 +0000
[    0.650749] random: cryptsetup urandom read with 1 bits of entropy available
[    1.236093] tsc: Refined TSC clocksource calibration: 3392.282 MHz
     aes-cbc   128b   675.3 MiB/s  2552.0 MiB/s
 serpent-cbc   128b    98.8 MiB/s   332.4 MiB/s
 twofish-cbc   128b   205.4 MiB/s   393.3 MiB/s
     aes-cbc   256b   495.3 MiB/s  1871.6 MiB/s
 serpent-cbc   256b    98.8 MiB/s   332.4 MiB/s
 twofish-cbc   256b   205.4 MiB/s   393.0 MiB/s
     aes-xts   256b  2113.5 MiB/s  2095.7 MiB/s
 serpent-xts   256b   343.4 MiB/s   326.1 MiB/s
 twofish-xts   256b   384.6 MiB/s   386.7 MiB/s
Sat, 22 Mar 2014 10:43:47 +0000
     aes-cbc   128b   675.9 MiB/s  2553.2 MiB/s
 serpent-cbc   128b    98.8 MiB/s   332.4 MiB/s
 twofish-cbc   128b   205.4 MiB/s   393.2 MiB/s
     aes-cbc   256b   495.3 MiB/s  1874.5 MiB/s
 serpent-cbc   256b    98.8 MiB/s   332.4 MiB/s
 twofish-cbc   256b   205.2 MiB/s   392.9 MiB/s
     aes-xts   256b  2114.0 MiB/s  2095.4 MiB/s
 serpent-xts   256b   342.9 MiB/s   326.0 MiB/s
 twofish-xts   256b   384.3 MiB/s   386.5 MiB/s
Sat, 22 Mar 2014 10:44:05 +0000
     aes-cbc   128b   675.1 MiB/s  2547.3 MiB/s
 serpent-cbc   128b    98.7 MiB/s   332.0 MiB/s
 twofish-cbc   128b   205.1 MiB/s   392.5 MiB/s
     aes-cbc   256b   494.0 MiB/s  1856.5 MiB/s
 serpent-cbc   256b    98.7 MiB/s   331.9 MiB/s
 twofish-cbc   256b   205.1 MiB/s   392.3 MiB/s
     aes-xts   256b  2088.9 MiB/s  2073.2 MiB/s
 serpent-xts   256b   342.7 MiB/s   325.6 MiB/s
 twofish-xts   256b   383.5 MiB/s   385.7 MiB/s
Sat, 22 Mar 2014 10:44:23 +0000