On Wed, Feb 3, 2021 at 1:26 PM Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: > > qemu-kvm VM starts with kernel 5.10.10 but fails with 5.11.0-rc5. > > Libvirt folks think this is a kernel bug, and have attached a > reproducer to the downstream bug report. > > "I've managed to reproduce and found that virBPFLoadProg() logs the > following message: > > in-kernel BTF is malformed\nprocessed 0 insns (limit 1000000) > max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n > " > > https://bugzilla.redhat.com/show_bug.cgi?id=1920857#c4 Looks like the bug was introduced in 5.11-rc5, the problem doesn't happen in rc4. As I mention in the downstream bug, I'm unable to compile a working kernel for bisect between rc4 and rc5 to find out the exact commit that introduced the problem, due to many messages like this: Feb 03 15:05:47 kernel: failed to validate module [coretemp] BTF: -22 Feb 03 15:05:47 kernel: failed to validate module [intel_powerclamp] BTF: -22 Feb 03 15:05:47 kernel: failed to validate module [irqbypass] BTF: -22 Feb 03 15:05:47 kernel: failed to validate module [intel_powerclamp] BTF: -22 Feb 03 15:05:47 kernel: failed to validate module [x86_pkg_temp_thermal] BTF: -22 -- Chris Murphy
