MSRSection: Linux Programmer's Manual (4)
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NAMEmsr - 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.
NOTESThe 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 ALSOIntel Corporation Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3B Appendix B, for an overview of the Intel CPU MSRs.
COLOPHONThis page is part of release 4.15 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/.
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