aarch64/fdt: fix cache sharing issue for cache passthrough on aarch64

We fixed the L2 and L3 level cache sharing issues and confirmed that the
L2 level cache is independent, while the L3 level cache is shared per-socket.

See:#5505

Signed-off-by: zhongbingnan <zhongbingnan@bytedance.com>

arch/src/aarch64/fdt.rs

@@ -98,7 +98,7 @@ pub enum CacheLevel {
     L3 = 3,
 }
 
-/// NOTE: CACHE SIZE file directory example,
+/// NOTE: cache size file directory example,
 /// "/sys/devices/system/cpu/cpu0/cache/index0/size".
 pub fn get_cache_size(cache_level: CacheLevel) -> u32 {
     let mut file_directory: String = "/sys/devices/system/cpu/cpu0/cache".to_string();
@@ -111,7 +111,7 @@ pub fn get_cache_size(cache_level: CacheLevel) -> u32 {
 
     let file_path = Path::new(&file_directory);
     if !file_path.exists() {
-        error!("File: {} not exist.", file_directory);
+        warn!("File: {} does not exist.", file_directory);
         0
     } else {
         info!("File: {} exist.", file_directory);
@@ -132,7 +132,7 @@ pub fn get_cache_size(cache_level: CacheLevel) -> u32 {
     }
 }
 
-/// NOTE: CACHE COHERENCY LINE SIZE file directory example,
+/// NOTE: coherency_line_size file directory example,
 /// "/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size".
 pub fn get_cache_coherency_line_size(cache_level: CacheLevel) -> u32 {
     let mut file_directory: String = "/sys/devices/system/cpu/cpu0/cache".to_string();
@@ -145,7 +145,7 @@ pub fn get_cache_coherency_line_size(cache_level: CacheLevel) -> u32 {
 
     let file_path = Path::new(&file_directory);
     if !file_path.exists() {
-        error!("File: {} not exist.", file_directory);
+        warn!("File: {} does not exist.", file_directory);
         0
     } else {
         info!("File: {} exist.", file_directory);
@@ -155,7 +155,7 @@ pub fn get_cache_coherency_line_size(cache_level: CacheLevel) -> u32 {
     }
 }
 
-/// NOTE: CACHE NUMBER OF SETS file directory example,
+/// NOTE: number_of_sets file directory example,
 /// "/sys/devices/system/cpu/cpu0/cache/index0/number_of_sets".
 pub fn get_cache_number_of_sets(cache_level: CacheLevel) -> u32 {
     let mut file_directory: String = "/sys/devices/system/cpu/cpu0/cache".to_string();
@@ -168,7 +168,7 @@ pub fn get_cache_number_of_sets(cache_level: CacheLevel) -> u32 {
 
     let file_path = Path::new(&file_directory);
     if !file_path.exists() {
-        error!("File: {} not exist.", file_directory);
+        warn!("File: {} does not exist.", file_directory);
         0
     } else {
         info!("File: {} exist.", file_directory);
@@ -178,6 +178,41 @@ pub fn get_cache_number_of_sets(cache_level: CacheLevel) -> u32 {
     }
 }
 
+/// NOTE: shared_cpu_list file directory example,
+/// "/sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_list".
+pub fn get_cache_shared(cache_level: CacheLevel) -> bool {
+    let mut file_directory: String = "/sys/devices/system/cpu/cpu0/cache".to_string();
+    let mut result = true;
+
+    match cache_level {
+        CacheLevel::L1D | CacheLevel::L1I => result = false,
+        CacheLevel::L2 => file_directory += "/index2/shared_cpu_list",
+        CacheLevel::L3 => file_directory += "/index3/shared_cpu_list",
+    }
+
+    if !result {
+        return false;
+    }
+
+    let file_path = Path::new(&file_directory);
+    if !file_path.exists() {
+        warn!("File: {} does not exist.", file_directory);
+        result = false;
+    } else {
+        info!("File: {} exist.", file_directory);
+
+        let src = fs::read_to_string(file_directory).expect("File not exists or file corrupted.");
+        let src = src.trim();
+        if src.is_empty() {
+            result = false;
+        } else {
+            result = src.contains('-') || src.contains(',');
+        }
+    }
+
+    result
+}
+
 /// Creates the flattened device tree for this aarch64 VM.
 #[allow(clippy::too_many_arguments)]
 pub fn create_fdt<T: DeviceInfoForFdt + Clone + Debug, S: ::std::hash::BuildHasher>(
@@ -255,6 +290,11 @@ fn create_cpu_nodes(
     fdt.property_u32("#size-cells", 0x0)?;
 
     let num_cpus = vcpu_mpidr.len();
+    let threads_per_core = vcpu_topology.unwrap_or_default().0;
+    let cores_per_package = vcpu_topology.unwrap_or_default().1;
+    let packages = vcpu_topology.unwrap_or_default().2;
+
+    let max_cpus: u32 = (threads_per_core * cores_per_package * packages).into();
 
     // Add cache info.
     // L1 Data Cache Info.
@@ -277,10 +317,14 @@ fn create_cpu_nodes(
     let mut l3_cache_line_size: u32 = 0;
     let mut l3_cache_sets: u32 = 0;
 
+    // Cache Shared Info.
+    let mut l2_cache_shared: bool = false;
+    let mut l3_cache_shared: bool = false;
+
     let cache_path = Path::new("/sys/devices/system/cpu/cpu0/cache");
     let cache_exist: bool = cache_path.exists();
     if !cache_exist {
-        error!("cache sysfs system does not exist.");
+        warn!("cache sysfs system does not exist.");
     } else {
         info!("cache sysfs system exists.");
         // L1 Data Cache Info.
@@ -302,6 +346,14 @@ fn create_cpu_nodes(
         l3_cache_size = get_cache_size(CacheLevel::L3);
         l3_cache_line_size = get_cache_coherency_line_size(CacheLevel::L3);
         l3_cache_sets = get_cache_number_of_sets(CacheLevel::L3);
+
+        // Cache Shared Info.
+        if l2_cache_size != 0 {
+            l2_cache_shared = get_cache_shared(CacheLevel::L2);
+        }
+        if l3_cache_size != 0 {
+            l3_cache_shared = get_cache_shared(CacheLevel::L3);
+        }
     }
 
     for (cpu_id, mpidr) in vcpu_mpidr.iter().enumerate().take(num_cpus) {
@@ -318,21 +370,6 @@ fn create_cpu_nodes(
         fdt.property_u32("reg", (mpidr & 0x7FFFFF) as u32)?;
         fdt.property_u32("phandle", cpu_id as u32 + FIRST_VCPU_PHANDLE)?;
 
-        if cache_exist && l1_d_cache_size != 0 && l1_i_cache_size != 0 {
-            // Add cache info.
-            fdt.property_u32("d-cache-size", l1_d_cache_size)?;
-            fdt.property_u32("d-cache-line-size", l1_d_cache_line_size)?;
-            fdt.property_u32("d-cache-sets", l1_d_cache_sets)?;
-
-            fdt.property_u32("i-cache-size", l1_i_cache_size)?;
-            fdt.property_u32("i-cache-line-size", l1_i_cache_line_size)?;
-            fdt.property_u32("i-cache-sets", l1_i_cache_sets)?;
-
-            if l2_cache_size != 0 {
-                fdt.property_u32("next-level-cache", L2_CACHE_PHANDLE)?;
-            }
-        }
-
         // Add `numa-node-id` property if there is any numa config.
         if numa_nodes.len() > 1 {
             for numa_node_idx in 0..numa_nodes.len() {
@@ -343,37 +380,89 @@ fn create_cpu_nodes(
             }
         }
 
+        if cache_exist && l1_d_cache_size != 0 && l1_i_cache_size != 0 {
+            // Add cache info.
+            fdt.property_u32("d-cache-size", l1_d_cache_size)?;
+            fdt.property_u32("d-cache-line-size", l1_d_cache_line_size)?;
+            fdt.property_u32("d-cache-sets", l1_d_cache_sets)?;
+
+            fdt.property_u32("i-cache-size", l1_i_cache_size)?;
+            fdt.property_u32("i-cache-line-size", l1_i_cache_line_size)?;
+            fdt.property_u32("i-cache-sets", l1_i_cache_sets)?;
+
+            if l2_cache_size != 0 && !l2_cache_shared {
+                fdt.property_u32(
+                    "next-level-cache",
+                    cpu_id as u32 + max_cpus + FIRST_VCPU_PHANDLE + L2_CACHE_PHANDLE,
+                )?;
+
+                let l2_cache_name = "l2-cache0";
+                let l2_cache_node = fdt.begin_node(l2_cache_name)?;
+                // PHANDLE is used to mark device node, and PHANDLE is unique. To avoid phandle
+                // conflicts with other device nodes, consider the previous CPU PHANDLE, so the
+                // CPU L2 cache PHANDLE must start from the largest CPU PHANDLE plus 1.
+                fdt.property_u32(
+                    "phandle",
+                    cpu_id as u32 + max_cpus + FIRST_VCPU_PHANDLE + L2_CACHE_PHANDLE,
+                )?;
+
+                fdt.property_string("compatible", "cache")?;
+                fdt.property_u32("cache-size", l2_cache_size)?;
+                fdt.property_u32("cache-line-size", l2_cache_line_size)?;
+                fdt.property_u32("cache-sets", l2_cache_sets)?;
+                fdt.property_u32("cache-level", 2)?;
+
+                if l3_cache_size != 0 && l3_cache_shared {
+                    let package_id: u32 = cpu_id as u32 / cores_per_package as u32;
+                    fdt.property_u32(
+                        "next-level-cache",
+                        package_id
+                            + num_cpus as u32
+                            + max_cpus
+                            + FIRST_VCPU_PHANDLE
+                            + L2_CACHE_PHANDLE
+                            + L3_CACHE_PHANDLE,
+                    )?;
+                }
+
+                fdt.end_node(l2_cache_node)?;
+            }
+            if l2_cache_size != 0 && l2_cache_shared {
+                warn!("L2 cache shared with other cpus");
+            }
+        }
+
         fdt.end_node(cpu_node)?;
     }
 
-    if cache_exist && l2_cache_size != 0 {
+    if cache_exist && l3_cache_size != 0 && !l2_cache_shared && l3_cache_shared {
-        let l2_cache_name = "l2-cache0";
+        let mut i: u32 = 0;
-        let l2_cache_node = fdt.begin_node(l2_cache_name)?;
+        while i < packages.into() {
-        fdt.property_u32("phandle", L2_CACHE_PHANDLE)?;
+            let l3_cache_name = "l3-cache0";
-        fdt.property_string("compatible", "cache")?;
+            let l3_cache_node = fdt.begin_node(l3_cache_name)?;
-        fdt.property_u32("cache-size", l2_cache_size)?;
+            // ARM L3 cache is generally shared within the package (socket), so the
-        fdt.property_u32("cache-line-size", l2_cache_line_size)?;
+            // L3 cache node pointed to by the CPU in the package has the same L3
-        fdt.property_u32("cache-sets", l2_cache_sets)?;
+            // cache PHANDLE. The L3 cache phandle must start from the largest L2
-        fdt.property_u32("cache-level", 2)?;
+            // cache PHANDLE plus 1 to avoid duplication.
+            fdt.property_u32(
+                "phandle",
+                i + num_cpus as u32
+                    + max_cpus
+                    + FIRST_VCPU_PHANDLE
+                    + L2_CACHE_PHANDLE
+                    + L3_CACHE_PHANDLE,
+            )?;
 
-        if l3_cache_size != 0 {
+            fdt.property_string("compatible", "cache")?;
-            fdt.property_u32("next-level-cache", L3_CACHE_PHANDLE)?;
+            fdt.property_null("cache-unified")?;
+            fdt.property_u32("cache-size", l3_cache_size)?;
+            fdt.property_u32("cache-line-size", l3_cache_line_size)?;
+            fdt.property_u32("cache-sets", l3_cache_sets)?;
+            fdt.property_u32("cache-level", 3)?;
+            fdt.end_node(l3_cache_node)?;
+
+            i += 1;
         }
-
-        fdt.end_node(l2_cache_node)?;
-    }
-
-    if cache_exist && l3_cache_size != 0 {
-        let l3_cache_name = "l3-cache0";
-        let l3_cache_node = fdt.begin_node(l3_cache_name)?;
-        fdt.property_u32("phandle", L3_CACHE_PHANDLE)?;
-        fdt.property_string("compatible", "cache")?;
-        fdt.property_null("cache-unified")?;
-        fdt.property_u32("cache-size", l3_cache_size)?;
-        fdt.property_u32("cache-line-size", l3_cache_line_size)?;
-        fdt.property_u32("cache-sets", l3_cache_sets)?;
-        fdt.property_u32("cache-level", 3)?;
-        fdt.end_node(l3_cache_node)?;
     }
 
     if let Some(topology) = vcpu_topology {