Implement on Core CPUs

cache_slice/src/arch.rs

@@ -198,24 +198,24 @@ const BROADWELL_XEON: XeonPerfCounters = XeonPerfCounters {
 const ALDER_LAKE_TO_RAPTOR_LAKE_CORE: CorePerfCounters = CorePerfCounters {
     max_slice: 10,
     msr_unc_perf_global_ctr: 0x2ff0,
-    val_enable_ctrs: 0, // TODO
+    val_enable_ctrs: 0x20000000, // To validate
     msr_unc_cbo_perfevtsel0: &[0x2000, 0x2008, 0x2010, 0x2018, 0x2020, 0x2028, 0x2030, 0x2038, 0x2040, 0x2048],
     msr_unc_cbo_per_ctr0: &[0x2002, 0x200a, 0x2012, 0x201a, 0x2022, 0x202a, 0x2032, 0x203a, 0x2042, 0x204a],
-    val_disable_ctrs: 0, // TODO
+    val_disable_ctrs: 0x0, // To validate
-    val_select_evt_core: 0, // TODO
+    val_select_evt_core: 0x408f34, // To validate
-    val_reset_ctrs: 0, // TODO
+    val_reset_ctrs: 0x0, // To validate
 };
 
 // TODO verify his on ICELAKE, and appropriate values. Also deal with backport Cypress Cove ?
 const CANNON_LAKE_TO_TIGER_LAKE_CORE: CorePerfCounters = CorePerfCounters {
-    max_slice: 8, // TODO
+    max_slice: 8, // To validate
     msr_unc_perf_global_ctr: 0xe01,
-    val_enable_ctrs: 0, // TODO
+    val_enable_ctrs: 0x20000000, // To validate
     msr_unc_cbo_perfevtsel0: &[0x700, 0x708, 0x710, 0x718, 0x720, 0x728, 0x730, 0x738],
     msr_unc_cbo_per_ctr0: &[0x702, 0x70a, 0x712, 0x71a, 0x722, 0x72a, 0x732, 0x73a],
-    val_disable_ctrs: 0x0, // TODO
+    val_disable_ctrs: 0x0, // To validate
-    val_select_evt_core: 0, // TODO
+    val_select_evt_core: 0x408f34, // To validate
-    val_reset_ctrs: 0x0, // TODO
+    val_reset_ctrs: 0x0, // To validate
 };
 
 const SKYLAKE_KABYLAKE_CORE: CorePerfCounters = CorePerfCounters {
@@ -229,13 +229,23 @@ const SKYLAKE_KABYLAKE_CORE: CorePerfCounters = CorePerfCounters {
     val_reset_ctrs: 0x0,
 };
 
+// This is documented in Intel SDM, 20.3.4.6 (in March 2024 edition)
+
 const SANDYBRIDGE_TO_BROADWELL_CORE: CorePerfCounters = CorePerfCounters {
     max_slice: 0,
     msr_unc_perf_global_ctr: 0x391,
+    // Go in MSR_UNC_PERF_GLOBAL_CTR EN (bit 29) set to one, and route PMI to core 1-4 upon overflow.
     val_enable_ctrs: 0x2000000f,
     msr_unc_cbo_perfevtsel0: &[0x700, 0x710, 0x720, 0x730],
     msr_unc_cbo_per_ctr0: &[0x706, 0x716, 0x726, 0x736],
     val_disable_ctrs: 0x0,
+    // Counter Mask (bit 28-24) 0, Inv (23) 0, EN (22) 1, OVF (20) 0, E (18) 0,
+    // Unit Mask (bit 15-8) 0x8f, Event Select (bit 7-0) 0x34
+    // Event selection from https://perfmon-events.intel.com
+    // UNC_CBO_CACHE_LOOKUP.ANY_MESI
+    // L3 Lookup any request that access cache and found line in MESI-state. 	EventSel=34H UMask=8FH
+    // Counter=0,1
     val_select_evt_core: 0x408f34,
+    // TODO
     val_reset_ctrs: 0x0,
 };

cache_slice/src/lib.rs

@@ -23,7 +23,7 @@ impl From<std::io::Error> for Error {
     }
 }
 
-const NUM_POKE: usize = 10000;
+const NUM_POKE: usize = 100000;
 
 unsafe fn poke(addr: *const u8) {
     for _i in 0..NUM_POKE {
@@ -79,7 +79,7 @@ unsafe fn monitor_xeon(addr: *const u8, cpu: u8, max_cbox: usize) -> Result<Vec<
     let mut results = Vec::new();
     for i in 0..max_cbox {
         let result = read_msr_on_cpu(performance_counters.msr_pmon_ctr0[i], cpu)?;
-        if (result as i64 - NUM_POKE as i64) < 0 {
+        if result < NUM_POKE as u64 {
             results.push(0);
         } else {
             results.push(result - NUM_POKE as u64);
@@ -89,7 +89,7 @@ unsafe fn monitor_xeon(addr: *const u8, cpu: u8, max_cbox: usize) -> Result<Vec<
     Ok(results)
 }
 
-fn monitor_core(addr: *const u8, cpu: u8, max_cbox: usize) -> Result<Vec<u64>, Error> {
+fn monitor_core(addr: *const u8, cpu: u8, mut max_cbox: usize) -> Result<Vec<u64>, Error> {
     // Note, we need to add the workaround for one missing perf counter here.
     let performance_counters = if let Some(p) = get_performance_counters_core() {
         p
@@ -98,6 +98,7 @@ fn monitor_core(addr: *const u8, cpu: u8, max_cbox: usize) -> Result<Vec<u64>, E
     };
 
     let workaround = if (performance_counters.max_slice as usize) + 1 == max_cbox {
+        max_cbox = performance_counters.max_slice as usize;
         true
     } else if (performance_counters.max_slice as usize) >= max_cbox {
         false
@@ -105,7 +106,39 @@ fn monitor_core(addr: *const u8, cpu: u8, max_cbox: usize) -> Result<Vec<u64>, E
         return Err(Error::InvalidParameter);
     };
 
-    unimplemented!()
+    write_msr_on_cpu(performance_counters.msr_unc_perf_global_ctr, cpu, performance_counters.val_disable_ctrs)?;
+
+    for i in 0..max_cbox {
+        write_msr_on_cpu(performance_counters.msr_unc_cbo_per_ctr0[i], cpu, performance_counters.val_reset_ctrs)?;
+    }
+
+    for i in 0..max_cbox {
+        write_msr_on_cpu(performance_counters.msr_unc_cbo_perfevtsel0[i], cpu, performance_counters.val_select_evt_core)?;
+    }
+
+    write_msr_on_cpu(performance_counters.msr_unc_perf_global_ctr, cpu, performance_counters.val_enable_ctrs)?;
+
+    unsafe { poke(addr) };
+
+    /*
+    // Commented out in original code : TODO, check if this makes any difference ?
+    write_msr_on_cpu(performance_counters.msr_unc_perf_global_ctr, cpu, performance_counters.val_disable_ctrs)?;
+
+    */
+    // Read counters
+    let mut results = Vec::new();
+    for i in 0..max_cbox {
+        let result = read_msr_on_cpu(performance_counters.msr_unc_cbo_per_ctr0[i], cpu)?;
+        if result < NUM_POKE as u64 {
+            results.push(0);
+        } else {
+            results.push(result - NUM_POKE as u64);
+        }
+    }
+
+    write_msr_on_cpu(performance_counters.msr_unc_perf_global_ctr, cpu, performance_counters.val_disable_ctrs)?;
+
+    Ok(results)
 }
 
 pub unsafe fn monitor_address(addr: *const u8, cpu: u8, max_cbox: u16) -> Result<Vec<u64>, Error> {