Enable ftrace in guest kernels

[ShadowCurse]

Changes

Enabled ftrace feature in guest kernels. This will help us to debug problems in the future.
Additionally we need to disable CONFIG_ARM64_ERRATUM_3194386 in aarch64 guest configs as this option hides ssbs feature from the guest user space and this breaks our integration test that verifies these features. The option itself was added in recent kernel versions and is intended for Cortex-X4 and Neoverse-V3 cpus, and we are not using those. Link: https://lore.kernel.org/stable/[email protected]/

Reason

Improve future debug-ability.

Examples:

root@ubuntu-fc-uvm:~# trace-cmd record -p function_graph -l 'hrtimer_*' -l 'lapic_*' -l 'wrmsr*'
...
root@ubuntu-fc-uvm:~# trace-cmd report
cpus=2
          <idle>-0     [001]   185.577231: funcgraph_entry:        1.040 us   |  hrtimer_get_next_event();
          <idle>-0     [001]   185.577234: funcgraph_entry:                   |  hrtimer_start_range_ns() {
          <idle>-0     [001]   185.577234: funcgraph_entry:                   |    hrtimer_force_reprogram() {
          <idle>-0     [001]   185.577235: funcgraph_entry:        3.120 us   |      lapic_next_deadline();
          <idle>-0     [001]   185.577238: funcgraph_exit:         3.910 us   |    }
          <idle>-0     [001]   185.577238: funcgraph_exit:         4.880 us   |  }
       trace-cmd-934   [000]   185.577401: funcgraph_entry:                   |  hrtimer_nanosleep() {
       trace-cmd-934   [000]   185.577401: funcgraph_entry:        0.300 us   |    hrtimer_init_sleeper();
       trace-cmd-934   [000]   185.577402: funcgraph_entry:        0.900 us   |    hrtimer_start_range_ns();
          <idle>-0     [000]   185.577850: funcgraph_entry:                   |  hrtimer_interrupt() {
          <idle>-0     [000]   185.577851: funcgraph_entry:        0.230 us   |    hrtimer_run_queues();
          <idle>-0     [000]   185.577852: funcgraph_entry:        0.210 us   |    hrtimer_forward();
          <idle>-0     [000]   185.577853: funcgraph_entry:        1.960 us   |    lapic_next_deadline();
          <idle>-0     [000]   185.577855: funcgraph_exit:         5.550 us   |  }
          <idle>-0     [001]   185.577870: funcgraph_entry:                   |  hrtimer_cancel() {
          <idle>-0     [001]   185.577870: funcgraph_entry:        0.250 us   |    hrtimer_active();
          <idle>-0     [001]   185.577871: funcgraph_entry:        0.370 us   |    hrtimer_try_to_cancel.part.0();
          <idle>-0     [001]   185.577871: funcgraph_exit:         1.880 us   |  }
          <idle>-0     [001]   185.577871: funcgraph_entry:        0.200 us   |  hrtimer_forward();
          <idle>-0     [001]   185.577872: funcgraph_entry:                   |  hrtimer_start_range_ns() {
          <idle>-0     [001]   185.577872: funcgraph_entry:                   |    hrtimer_reprogram() {
          <idle>-0     [001]   185.577872: funcgraph_entry:        2.030 us   |      lapic_next_deadline();
          <idle>-0     [001]   185.577875: funcgraph_exit:         2.560 us   |    }
          <idle>-0     [001]   185.577875: funcgraph_exit:         3.100 us   |  }

License Acceptance

By submitting this pull request, I confirm that my contribution is made under
the terms of the Apache 2.0 license. For more information on following Developer
Certificate of Origin and signing off your commits, please check
CONTRIBUTING.md.

PR Checklist

• If a specific issue led to this PR, this PR closes the issue.
• The description of changes is clear and encompassing.
• Any required documentation changes (code and docs) are included in this
  PR.
• API changes follow the Runbook for Firecracker API changes.
• User-facing changes are mentioned in CHANGELOG.md.
• All added/changed functionality is tested.
• New TODOs link to an issue.
• Commits meet
  contribution quality standards.

---

• This functionality cannot be added in rust-vmm.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.32%. Comparing base (9104425) to head (2e878b7).
Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4801   +/-   ##
=======================================
  Coverage   84.32%   84.32%           
=======================================
  Files         249      249           
  Lines       27521    27521           
=======================================
  Hits        23206    23206           
  Misses       4315     4315           

Flag	Coverage Δ
5.10-c5n.metal	84.54% <ø> (ø)
5.10-m5n.metal	84.53% <ø> (ø)
5.10-m6a.metal	83.81% <ø> (-0.01%)	⬇️
5.10-m6g.metal	80.89% <ø> (ø)
5.10-m6i.metal	84.52% <ø> (ø)
5.10-m7g.metal	80.89% <ø> (ø)
6.1-c5n.metal	84.54% <ø> (ø)
6.1-m5n.metal	84.52% <ø> (-0.01%)	⬇️
6.1-m6a.metal	83.81% <ø> (-0.01%)	⬇️
6.1-m6g.metal	80.89% <ø> (ø)
6.1-m6i.metal	84.51% <ø> (-0.01%)	⬇️
6.1-m7g.metal	80.89% <ø> (ø)

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[roypat]

Do we also add trace-cmd to our rootfs? We could just fiddle with the sysfs, but trace-cmd is nicer

[ShadowCurse]

Do we also add trace-cmd to our rootfs? We could just fiddle with the sysfs, but trace-cmd is nicer

I can used trace-cmd with our rootfs, so it is already there.

[roypat]

Do we also add trace-cmd to our rootfs? We could just fiddle with the sysfs, but trace-cmd is nicer

I can used trace-cmd with our rootfs, so it is already there.

oh, neat!