msr(4) - phpMan

MSR(4)                              Linux Programmer's Manual                              MSR(4)

NAME
       msr - x86 CPU MSR access device

DESCRIPTION
       /dev/cpu/CPUNUM/msr  provides  an interface to read and write the model-specific registers
       (MSRs) of an x86  CPU.   CPUNUM  is  the  number  of  the  CPU  to  access  as  listed  in
       /proc/cpuinfo.

       The register access is done by opening the file and seeking to the MSR number as offset in
       the file, and then reading or writing in chunks of 8 bytes.  An I/O transfer of more  than
       8 bytes means multiple reads or writes of the same register.

       This  file  is protected so that it can be read and written only by the user root, or mem-
       bers of the group root.

NOTES
       The msr driver is not auto-loaded.  On modular kernels you might need to use the following
       command to load it explicitly before use:

           $ modprobe msr

SEE ALSO
       Intel  Corporation  Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3B
       Appendix B, for an overview of the Intel CPU MSRs.

COLOPHON
       This page is part of release 5.10 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at https://www.kernel.org/doc/man-pages/.

Linux                                       2009-03-31                                     MSR(4)

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