 
You need to be ROOT or use SUDO to execute MSRTOOL.

Note that you need /dev/cpu/*/msr available to run msrtool in Linux.


syntax: msrtool [-hvqrkl] [-c cpu] [-m system] [-t target ...]
         [-i addr=hi[:]lo] | [-s file] | [-d [:]file] | addr...
  -h     show this help text                                                                                                                  
  -v     be verbose                                                                                                                           
  -q     be quiet (overrides -v)
  -r     include [Reserved] values
  -k     list all known systems and targets
  -l     list MSRs and bit fields for current target(s) (-kl for ALL targets!)
  -c     access MSRs on the specified CPU, default=0
  -m     force a system, e.g: -m linux
  -t     force a target, can be used multiple times, e.g: -t geodelx -t cs5536
  -i     immediate mode
         decode hex addr=hi:lo for the target without reading hw value
         e.g: -i 4c00000f=f2f100ff56960004
  -s     stream mode
         read one MSR address per line and append current hw value to the line
         use the filename - for stdin/stdout
         using -l -s ignores input and will output all MSRs with values
  -d     diff mode
         read one address and value per line and compare with current hw value,
         printing differences to stdout. use the filename - to read from stdin
         use :file or :- to reverse diff, normally hw values are considered new
  addr.. direct mode, read and decode values for the given MSR address(es)


Examples:

msrtool 0x20000018

./msrtool 0x200000{18,19,1a,1b,1c,1d} 0x4c0000{0f,14}