msr - x86 CPU MSR access device
/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 members of the group root.
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
Intel Corporation Intel 64 and IA-32 Architectures Software Developer's Manual
Volume 3B Appendix B, for an overview of the Intel CPU MSRs.
This page is part of release 5.03 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/.