[dv] Add riscv_ram_intg_test

This test injects a fault into different MuBi encoded signals within
the prim_ram_1p_scr and prim_ram_1p_adv and checks whether a fatal
alert is triggered.

This PR is based on lowRISC#2182 and closes lowRISC#2173.

Signed-off-by: Pascal Nasahl <[email protected]>

dv/uvm/core_ibex/riscv_dv_extension/testlist.yaml

@@ -689,6 +689,21 @@
   rtl_params:
     SecureIbex: 1
 
+- test: riscv_ram_intg_test
+  description: >
+    Randomly corrupt one of the RAM MUBI values in the middle of program execution
+  iterations: 15
+  gen_test: riscv_rand_instr_test
+  gen_opts: >
+    +instr_cnt=10000
+    +num_of_sub_program=5
+    +gen_all_csrs_by_default=1
+    +add_csr_write=MSTATUS,MEPC,MCAUSE,MTVAL,0x7c0,0x7c1
+    +no_csr_instr=0
+  rtl_test: core_ibex_ram_intg_test
+  rtl_params:
+    SecureIbex: 1
+
 - test: riscv_icache_intg_test
   description: >
     Randomly corrupt the instruction cache once in the middle of program execution

dv/uvm/core_ibex/tests/core_ibex_test_lib.sv

@@ -199,6 +199,124 @@ class core_ibex_rf_intg_test extends core_ibex_base_test;
 
 endclass
 
+class core_ibex_ram_intg_test extends core_ibex_base_test;
+  `uvm_component_utils(core_ibex_ram_intg_test)
+  `uvm_component_new
+
+  uvm_report_server rs;
+
+  virtual task send_stimulus();
+    int          rnd_delay;
+    int unsigned bit_idx;
+    logic [31:0] orig_val, glitch_val;
+    logic        alert_major_internal;
+    string       glitch_path, alert_major_internal_path;
+    string       glitch_paths[];
+    string       signals[];
+    string       scr_signals[];
+    int unsigned scr_signals_idx;
+    string       adv_signals[];
+    int unsigned adv_signals_idx;
+    string       ram_path;
+    int unsigned bank_idx, ram_idx, glitch_idx;
+    string       top_path = "core_ibex_tb_top.dut.u_ibex_top";
+    string       bank_paths[];
+
+    // Hard coded paths for the data and tag bank.
+    bank_paths = {
+      "gen_rams.gen_rams_inner[0].gen_scramble_rams.tag_bank",
+      "gen_rams.gen_rams_inner[1].gen_scramble_rams.tag_bank",
+      "gen_rams.gen_rams_inner[0].gen_scramble_rams.data_bank",
+      "gen_rams.gen_rams_inner[1].gen_scramble_rams.data_bank"
+    };
+
+    // All banks contain a single prim_ram_1p_adv instance.
+    ram_path = "u_prim_ram_1p_adv";
+
+    scr_signals = {
+      "write_en_d",
+      "write_en_q",
+      "addr_collision_d",
+      "addr_collision_q",
+      "write_scr_pending_d",
+      "write_pending_q",
+      "rvalid_q",
+      "read_en_buf",
+      "addr_match_buf"
+    };
+
+    adv_signals = {
+      "req_q",
+      "req_d",
+      "write_q",
+      "write_d",
+      "rvalid_q",
+      "rvalid_d",
+      "rvalid_sram_q",
+      "rvalid_sram_d"
+    };
+
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(scr_signals_idx, scr_signals_idx < scr_signals.size();)
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(adv_signals_idx, adv_signals_idx < adv_signals.size();)
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(bank_idx, bank_idx < bank_paths.size();)
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(rnd_delay, rnd_delay > 1000; rnd_delay < 10_000;)
+
+    signals = {
+      scr_signals[scr_signals_idx],
+      adv_signals[adv_signals_idx]
+    };
+
+    // Assemble paths and do the final muxing of the target glitch path below.
+    glitch_paths = {
+      $sformatf("%s.%s.%s", top_path, bank_paths[bank_idx], signals[0]),
+      $sformatf("%s.%s.%s.%s", top_path, bank_paths[bank_idx], ram_path, signals[1])
+    };
+
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(glitch_idx, glitch_idx < glitch_paths.size();)
+
+    glitch_path = glitch_paths[glitch_idx];
+
+    vseq.start(env.vseqr);
+    clk_vif.wait_n_clks(rnd_delay);
+
+    `uvm_info(`gfn, $sformatf("Reading value of %s", glitch_path), UVM_LOW)
+    `DV_CHECK_FATAL(uvm_hdl_read(glitch_path, orig_val));
+    `uvm_info(`gfn, $sformatf("Read %x", orig_val), UVM_LOW)
+
+    `DV_CHECK_STD_RANDOMIZE_WITH_FATAL(bit_idx, bit_idx < 4;)
+
+    glitch_val = orig_val;
+    glitch_val[bit_idx] = ~glitch_val[bit_idx];
+
+    // Disable TB assertion for alerts.
+    `DV_ASSERT_CTRL_REQ("tb_no_alerts_triggered", 1'b0)
+
+    `uvm_info(`gfn, $sformatf("Forcing %s to value 'h%0x", glitch_path, glitch_val), UVM_LOW)
+    `DV_CHECK_FATAL(uvm_hdl_force(glitch_path, glitch_val));
+
+    // Leave glitch applied for one clock cycle.
+    clk_vif.wait_n_clks(1);
+
+    // Check that the alert matches our expectation.
+    alert_major_internal_path = $sformatf("%s.alert_major_internal_o", top_path);
+    `DV_CHECK_FATAL(uvm_hdl_read(alert_major_internal_path, alert_major_internal))
+    `DV_CHECK_FATAL(alert_major_internal, "Major alert did not fire!")
+
+    // Release glitch.
+    `DV_CHECK_FATAL(uvm_hdl_release(glitch_path))
+    `uvm_info(`gfn, $sformatf("Releasing force of %s", glitch_path), UVM_LOW)
+
+    // Re-enable TB assertion for alerts.
+    `DV_ASSERT_CTRL_REQ("tb_no_alerts_triggered", 1'b1)
+
+    // Complete the test at this point because cosimulation does not model faults so will cause
+    // a mis-match and a test failure.
+    rs = uvm_report_server::get_server();
+    rs.report_summarize();
+    $finish();
+  endtask
+endclass
+
 // Test that corrupts the instruction cache and checks that an appropriate alert occurs.
 class core_ibex_icache_intg_test extends core_ibex_base_test;