MSR-SAFE
========
The msr-safe.ko module is comprised of the following source files:
Makefile
msr_entry.c Original MSR driver with added calls to batch and
whitelist implementations.
msr_batch.[ch] MSR batching implementation
msr_whitelist.[ch] MSR Whitelist implementation
whitelists Sample text whitelist that may be input to msr_safe
Kernel Build & Load
-------------------
Building the msr-safe.ko module can be done with the commands below. A
successful load of the msr-safe kernel module will have `msr_batch` and
`msr_whitelist` in `/dev/cpu`, and will have an `msr_safe` present under each
CPU directory in `/dev/cpu/*`.
git clone https://github.com/LLNL/msr-safe
cd msr-safe
make
insmod msr-safe.ko
Configuration Notes After Install
---------------------------------
Setup permissions and group ownership for `/dev/cpu/msr_batch`,
`/dev/cpu/msr_whitelist`, and `/dev/cpu/*/msr_safe` as you like since the
whitelist will protect you from harm.
Sample whitelists for specific architectures are provided in `whitelists/`
directory. These are meant to be a starting point, and should be used with
caution. Each site may add to, remove from, or modify the write masks in the
whitelist depending on specific needs.
To configure whitelist:
cat whitelist/wl_file > /dev/cpu/msr_whitelist
Where `wl_file` can be determined as follows:
printf 'wl_%.2x%x\n' $(lscpu | grep "CPU family:" | awk -F: '{print $2}') $(lscpu | grep "Model:" | awk -F: '{print $2}')
To confirm successful whitelist configured:
cat /dev/cpu/msr_whitelist
To enumerate the current whitelist (i.e., implies whitelist was loaded
successfully):
cat < /dev/cpu/msr_whitelist
To remove whitelist (as root):
echo > /dev/cpu/msr_whitelist
msrsave
-------
The msrsave utility provides a mechanism for saving and restoring MSR values
based on entries in the whitelist. To restore MSR values, the register must
have an appropriate writemask.
Release
-------
msr-safe is released under the GPLv3 license. For more details, please see the
[LICENSE](https://github.com/LLNL/msr-safe/blob/master/LICENSE) file.