Artifact For: DelayAVF: Calculating Architectural Vulnerability Factors for Delay Faults

This is the artifact for DelayAVF: Calculating Architectural Vulnerability Factors for Delay Faults. The artifact contains the SDF-injection framework, scripts to synthesize and analyze the Ibex core, and the source code for the benchmarks. A dockerfile to run the pipeline is included for convenience. Note the ibex submodule, so please run git submodule init && git submodule update initially.

Contained Code:

• The benchmarks are in tests/benchmarks/ported_beebs_benchmarks/
• Python scripts to parse RTL into a json-description of a circuit
• An SDF-injection framework that takes as input json-description of a circuit and a config file describing the fault injection campaign, and output dynamically reachable sets (in delayFaultSimulatorRust)
• Python scripts and an ibex testbench that takes dynamically reachable sets as inputs, and computes a structure's AVF value.

Analyzing the Ibex Core

To analyze the DelayFaultAVF of a given Ibex structure with respect to a certain benchmark, run the following code:

1. First, run git submodule init && git submodule update and then build and launch the docker container through the script ./build_and_run_docker.sh. You will be dropped into a docker shell.
2. Now, cd into tests/ibex/testbench/.
3. Pick a configuration that you want to run. A configuration is a json file, describing the parameters of the fault injection campaign like so. The micro configuration files are provided in tests/ibex/testbench/configs/beeps. The configuration file to be read as follows:

{
    "synth_file": "syn_out/ibex_top_netlist.v", //Temporary output files
    "sub_synth_file": "syn_out/ibex_top_submodule_netlist.v",
    "submodule_name": "ibex_decoder", // The structure that should be analyzed
    "short_submodule_name": "decoder",
    "pdk_path": "../../../tech_libraries/nangate45/lib/NangateOpenCellLibrary_typical_nocomplex.lib", //The pdk
    "top_path": "TOP.sim_top.dut.cpu.cpu.",
    "clk_path": "TOP.sim_top.dut.cpu.cpu.clk_i",
    "hex_payload": "../../benchmarks/ported_beebs_benchmarks/md5.hex", //The benchmark that we want to run
    "delay_range": [ //What length of delays to compute the AVF for. This list is to comput the delayAVF with respect to 10%,20%, ..,90% delay
        0.1,
        0.2,
        0.3,
        0.4,
        0.5,
        0.6,
        0.7,
        0.8,
        0.9
    ],
    "percent_sampled_cycles_delay": 4, //Sampling rate for the injected delayFaults
    "percent_sampled_cycles_particle": 50,
    "ecc_on": 0,
    "output_dir": "beeps_benchmark_data/results/md5/decoder/" //Output folder
}

4. To evaluate a structure's delayAVF, execute the run_all.sh <path-to-config.json> script in the tests/ibex/testbench directory. For example, to compute the decoder's DelayAVF with respect to the md5 benchmark, run:

./run_all.sh configs/beeps/md5_decoder.dict

Roughly, the framework follows the following workflow:

• First, synthesize the Ibex core into RTL, using the freepdk-45nm library and build the benchmarks.
• Then, cconvert the RTL into a json representation.
• Call the rust SDF injector to determine dynamically reachable sets.
• Use a verilator testbench to determine groupACEness and aggregate the results.

5. The results will be stored in <output_dir>/protection_rates.json, e.g., tests/ibex/beeps_benchmark_data/results/md5/decoder/protection_rates.json. To be read as:

{
  "delayavf_per_delay": {
    "184": { // Discretized length of injected delay
      "delayAVF": 0,
    },
    "1656": {
      "delayAVF": 0.012679360419095308, //DelayAVF value
    }
  },
  "clk_period": 1840, //Discretized length of the clock period.
}

6. you can compute the delayAVF of multiple structure/benchmark combinations and compare the results.