Measure the Cost of Traps, World Switches, and Misaligned Operat…

config/test/spike-latency-benchmark-protect-payload.toml

@@ -0,0 +1,23 @@
+# A simple configuration to run on the Spike platform
+
+[log]
+level = "info"
+color = true
+
+[vcpu]
+max_pmp = 8
+delegate_perf_counters=true
+
+[platform]
+name = "spike"
+
+[target.miralis]
+# Build profile for Miralis (dev profile is set by default)
+profile = "release"
+
+[target.firmware]
+# Build profile for the firmware (dev profile is set by default)
+profile = "release"
+
+[policy]
+name = "protect_payload"

firmware/tracing_firmware/Cargo.toml

@@ -11,3 +11,4 @@ path = "main.rs"
 
 [dependencies]
 miralis_abi = { path = "../../crates/abi" }
+config_helpers = { path = "../../crates/config_helpers" }

firmware/tracing_firmware/main.rs

@@ -9,10 +9,15 @@
 
 use core::arch::{asm, global_asm};
 
+use config_helpers::parse_str_or;
 use miralis_abi::{failure, log, setup_binary, success};
 
 setup_binary!(main);
 
+const POLICY_NAME: &str = parse_str_or(option_env!("MIRALIS_POLICY_NAME"), "default_policy");
+
+const PROTECT_PAYLOAD_POLICY: &str = "protect_payload";
+
 fn enable_mcycle_in_smode() {
     unsafe {
         // This allows to read cycle in S-mode - for the payload
@@ -122,6 +127,11 @@ fn operating_system() {
     }
 
     measure(false);
+
+    if POLICY_NAME == PROTECT_PAYLOAD_POLICY {
+        measure_misaligned();
+    }
+
     success();
 }
 
@@ -136,14 +146,29 @@ fn measure(is_firmware: bool) {
     let average_measure = trigger_ctx_switch_to_firmware_batched();
 
     if is_firmware {
-        log::info!("Firmware cost : {}", average_measure);
+        log::info!("Firmware cost {} : {}", POLICY_NAME, average_measure);
     } else {
-        log::info!("Payload cost : {}", average_measure);
+        log::info!("Payload cost {} : {}", POLICY_NAME, average_measure);
     }
 
     print_statistics(stats);
 }
 
+fn measure_misaligned() {
+    let mut values: [usize; NB_REPEATS] = [0; NB_REPEATS];
+
+    for i in 0..NB_REPEATS {
+        values[i] = trigger_misaligned_op()
+    }
+
+    let stats = get_statistics(values);
+    let average_measure = trigger_ctx_switch_to_firmware_batched();
+
+    log::info!("Misaligned cost {} : {}", POLICY_NAME, average_measure);
+
+    print_statistics(stats);
+}
+
 fn trigger_ctx_switch_to_firmware() -> usize {
     let begin: u64;
     let end: u64;
@@ -179,6 +204,53 @@ fn trigger_ctx_switch_to_firmware_batched() -> usize {
     (end - begin) as usize / NB_REPEATS
 }
 
+pub fn trigger_misaligned_op() -> usize {
+    let begin: u64;
+    let end: u64;
+
+    let misaligned_address_8_bytes: usize = 0x80600301;
+
+    unsafe {
+        // Read the `mcycle` register (assuming 64-bit RISC-V)
+        asm!("csrr {}, cycle", out(reg) begin);
+        // We trigger a misaligned operation
+        asm!(
+        "ld {r}, 0({addr})",
+        addr = in(reg) misaligned_address_8_bytes,
+        r = out(reg) _,
+        );
+        // Read the `mcycle` register (assuming 64-bit RISC-V)
+        asm!("csrr {}, cycle", out(reg) end);
+    }
+
+    (end - begin) as usize
+}
+
+pub fn trigger_misaligned_op_batched() -> usize {
+    let begin: u64;
+    let end: u64;
+
+    let misaligned_address_8_bytes: usize = 0x80600301;
+
+    unsafe {
+        // Read the `mcycle` register (assuming 64-bit RISC-V)
+        asm!("csrr {}, cycle", out(reg) begin);
+
+        for _ in 0..NB_REPEATS {
+            // We trigger a misaligned operation
+            asm!(
+            "ld {r}, 0({addr})",
+            addr = in(reg) misaligned_address_8_bytes,
+            r = out(reg) _,
+            );
+        }
+        // Read the `mcycle` register (assuming 64-bit RISC-V)
+        asm!("csrr {}, cycle", out(reg) end);
+    }
+
+    (end - begin) as usize / NB_REPEATS
+}
+
 #[derive(Debug)]
 pub struct Statistics {
     mean: usize,

miralis.toml

@@ -32,6 +32,9 @@ path = "config/test/spike-protect-payload.toml"
 [config.spike-benchmark]
 path = "./config/test/spike-latency-benchmark.toml"
 
+[config.spike-benchmark-protect-payload]
+path = "./config/test/spike-latency-benchmark-protect-payload.toml"
+
 ## ——————————————————————————— Integration Tests ———————————————————————————— ##
 
 [test.ecall]
@@ -226,3 +229,8 @@ description = "The most basic test, which directly exit with an ecall to Miralis
 firmware = "tracing_firmware"
 config = "spike-benchmark"
 description = "The firmware and configuration we use to measure cycles in the CI"
+
+[test.spike-benchmark-protect-payload]
+firmware = "tracing_firmware"
+config = "spike-benchmark-protect-payload"
+description = "The firmware and configuration we use to measure cycles in the CI using the protect payload policy"

misc/push_stats.sh

@@ -49,8 +49,11 @@ file="cycles.txt"
 cargo run -- run --firmware tracing_firmware --config ./config/test/spike-latency-benchmark.toml > $file
 
 # Extract the number after "firmware cost:"
-firmware_cost=$(grep -i "Firmware cost :" "$file"  | sed -E 's/.*Firmware cost : ([0-9]+).*/\1/')
-payload_cost=$(grep -i "Payload cost :" "$file" | sed -E 's/.*Payload cost : ([0-9]+).*/\1/')
+firmware_cost=$(grep -i "Firmware cost default_policy :" "$file"  | sed -E 's/.*Firmware cost default_policy : ([0-9]+).*/\1/')
+payload_cost=$(grep -i "Payload cost default_policy :" "$file" | sed -E 's/.*Payload cost default_policy : ([0-9]+).*/\1/')
+firmware_cost_protect=$(grep -i "Firmware cost protect_payload:" "$file"  | sed -E 's/.*Firmware cost protect_payload : ([0-9]+).*/\1/')
+payload_cost_protect=$(grep -i "Payload cost protect_payload :" "$file" | sed -E 's/.*Payload cost protect_payload : ([0-9]+).*/\1/')
+misaligned_cost_protect=$(grep -i "Misaligned cost protect_payload :" "$file" | sed -E 's/.*Misaligned cost protect_payload : ([0-9]+).*/\1/')
 
 # Check if a number was found
 if [ -n "$firmware_cost" ]; then
@@ -66,17 +69,42 @@ else
     echo "No firmware cost found in the file."
 fi
 
+# Check if a number was found
+if [ -n "$firmware_cost_protect" ]; then
+    echo "Firmware cost: $firmware_cost_protect"
+else
+    echo "No firmware cost found in the file."
+fi
+
+# Check if a number was found
+if [ -n "$payload_cost_protect" ]; then
+    echo "Payload cost: $payload_cost_protect"
+else
+    echo "No firmware cost found in the file."
+fi
+
+# Check if a number was found
+if [ -n "$misaligned_cost_protect" ]; then
+    echo "Payload cost: $misaligned_cost_protect"
+else
+    echo "No firmware cost found in the file."
+fi
+
+
 # ———————————————————————————————— Push stats ———————————————————————————————— #
 
 echo "Commit: $git_commit"
 echo "Current date: $current_date"
 echo "Miralis size: $miralis_size bytes"
 echo "Build time: $build_time"
-echo "Miralis <--> Firmware latency in cycles: " firmware_cost
+echo "Miralis <--> Firmware latency in cycles: " $firmware_cost
 echo "Payload <--> Firmware latency in cycles: " $payload_cost
+echo "[PROTECT PAYLOAD] Miralis <--> Firmware latency in cycles: " $firmware_cost_protect
+echo "[PROTECT PAYLOAD] Payload <--> Firmware latency in cycles: " $payload_cost_protect
+echo "[PROTECT PAYLOAD] Cost of a misaligned emulation: " $misaligned_cost_protect
 
 if [ "$1" = "--commit" ]; then
-    csv_entry="$git_commit, $current_date, $miralis_size, $build_time, $firmware_cost, $payload_cost"
+    csv_entry="$git_commit, $current_date, $miralis_size, $build_time, $firmware_cost, $payload_cost,$firmware_cost_protect,$payload_cost_protect,$misaligned_cost_protect"
     echo $csv_entry >> "$miralis_stats_csv_path"
     echo "Added CSV entry to $miralis_stats_csv_path"
 fi

runner/src/artifacts.rs

@@ -347,7 +347,7 @@ pub fn build_target(target: Target, cfg: &Config) -> PathBuf {
             let linker_args = format!("-C link-arg=-Tmisc/linker-script.x -C link-arg=--defsym=_start_address={firmware_address}");
             build_cmd.env("RUSTFLAGS", linker_args);
             build_cmd.env("IS_TARGET_FIRMWARE", "true");
-            build_cmd.envs(cfg.benchmark.build_envs());
+            build_cmd.envs(cfg.build_envs());
             build_cmd.arg("--package").arg(firmware);
 
             if firmware == "miralis" {
@@ -365,7 +365,7 @@ pub fn build_target(target: Target, cfg: &Config) -> PathBuf {
             let linker_args = format!("-C link-arg=-Tmisc/linker-script.x -C link-arg=--defsym=_start_address={payload_address}");
             build_cmd.env("RUSTFLAGS", linker_args);
             build_cmd.env("IS_TARGET_FIRMWARE", "false");
-            build_cmd.envs(cfg.benchmark.build_envs());
+            build_cmd.envs(cfg.build_envs());
             build_cmd.arg("--package").arg(payload_name);
         }
     }