# Linux Kernel Module Cheat

### 10.2. gem5 KVM

While gem5 does have KVM, as of 2019 its support has not been very good, because debugging it is harder and people haven’t focused intensively on it.

X86 was broken with pending patches: https://www.mail-archive.com/gem5-users@gem5.org/msg15046.html It failed immediately on:

    panic: KVM: Failed to enter virtualized mode (hw reason: 0x80000021)

also mentioned at:

- https://stackoverflow.com/questions/62687463/gem5-kvm-doesnt-work-with-error-0x80000021

- https://gem5-users.gem5.narkive.com/8DBihuUx/running-fs-py-with-x86kvmcpu-failed

Bibliography:

- ARM thread: https://stackoverflow.com/questions/53523087/how-to-run-gem5-on-kvm-on-arm-with-multiple-cores