Generic Table First draft

proto/p4/GenericTable.md

@@ -0,0 +1,124 @@
+# GenericTable example p4info
+
+Below is an example for realizing MulticastGroupEntry as a GenericTable.
+The key (MatchFields) comprise of only the group_id. 2 different ways of
+defining the data fields has been presented. Only 1 of them is required.
+
+```
+generic_tables {
+  generic_table_type_id : 145
+  generic_table_type_name : "MulticastGroup"
+  generic_table_properties : {
+    read-only : False
+  }
+  generic_table_properties : {
+    modify-only : False
+  }
+  generic_table_properties : {
+    reset-only : False
+  }
+  generic_table_properties : {
+    volatile : False
+  }
+  generic_table_properties : {
+    indexed : True
+  }
+
+  preamble {
+    id: 45332650
+    name: "MulticastGroup"
+    alias: "multicast_group"
+  }
+  generic_match_fields {
+    id: 1
+    name: "multicast_group_id"
+    match_type: EXACT
+    type {
+      type : "bytes"
+      width : 32
+    }
+  }
+  union_refs {
+    id: 23557840
+  }
+  size: 1024
+}
+```
+
+In the below one, both `instance` and `port` are separate
+repeated fields. So the check on `len(instance_array) == len(port_array)`
+needs to be a runtime check. This however keeps implementation simpler
+and faster since we avoid further recursive nesting.
+
+`port` is a varbytes of max size 64 bits each. The field has a `repeated_type`
+as well, so it is defined as list of varbits through p4info.
+
+```
+unions {
+  preamble {
+    id: 23557840
+    name: "multicast_group_member_add"
+    alias: "multicast_group_member_add"
+  }
+  params {
+    id: 1
+    name: "instance"
+    type {
+      container_type : "list"
+      container_max_size : 10
+      type : "bytes"
+      width : 32
+    }
+  }
+  params {
+    id: 2
+    name: "port"
+    type {
+      container_type : "list"
+      container_max_size : 10
+      type : "varbytes"
+      max_bit_width : 64
+    }
+  }
+}
+
+```
+
+The below one is similar to the above but both `instance` and `port` have
+been converted to a list of structs.
+
+```
+unions {
+  preamble {
+    id: 23557841
+    name: "multicast_group_member_add_2"
+    alias: "multicast_group_member_add_2"
+  }
+  params {
+    id: 1
+    name: "replica"
+    type {
+      container_type : "list"
+      type : "struct"
+    }
+    params {
+      param {
+        id: 1
+        name: "instance"
+        type {
+          type : "bytes"
+          width : 32
+        }
+      }
+      param : {
+        id: 2
+        name: "port"
+        type {
+          type : "varbytes"
+          max_bit_width : 64
+        }
+      }
+    }
+  }
+}
+```

proto/p4/config/v1/p4info.proto

@@ -36,6 +36,8 @@ message P4Info {
   repeated ValueSet value_sets = 10;
   repeated Register registers = 11;
   repeated Digest digests = 12;
+  repeated GenericTable generic_tables = 13;
+  repeated Union unions = 14;
   repeated Extern externs = 100;
   P4TypeInfo type_info = 200;
 }
@@ -103,6 +105,7 @@ message P4Ids {
     DIRECT_METER = 0x15;
     REGISTER = 0x16;
     DIGEST = 0x17;
+    GENERIC_TABLE = 0x18;
 
     // externs for other architectures (vendor extensions)
     OTHER_EXTERNS_START = 0x80;
@@ -114,6 +117,22 @@ message P4Ids {
   }
 }
 
+// A subtype of P4IDs for GenericTables
+message GenericTableType {
+  // The ID space is for Generic tables. In the Preamble ID, the MSB will be
+  // 0x18 but the next MSB is reserved for this enum. This shortens the ID
+  // space for tables in each type but it is still 64k (16 bits) for each table
+  enum Prefix {
+
+    GENERIC_TABLES_START = 0x00;
+
+    // max value for an unsigned 8-bit byte
+    MAX = 0xff;
+    // requires protoc >= 3.5.0
+    // reserved 0x100 to max;
+  }
+}
+
 message Preamble {
   // ids share the same number-space; e.g. table ids cannot overlap with counter
   // ids. Even though this is irrelevant to this proto definition, the ids are
@@ -397,3 +416,89 @@ message Digest {
   Preamble preamble = 1;
   P4DataTypeSpec type_spec = 2;
 }
+
+////// Begin : GenericTables messages
+
+message GenericMatchField {
+  uint32 id = 1;
+  string name = 2;
+  bool repeated = 3;
+  GenericDataTypeSpec type_spec = 4;
+  enum MatchType {
+    UNSPECIFIED = 0;
+    EXACT = 2;
+    LPM = 3;
+    TERNARY = 4;
+    RANGE = 5;
+    OPTIONAL = 6;
+  }
+  oneof match {
+    MatchType match_type = 5;
+    // used for architecture-specific match types which are not part of the core
+    // P4 language or of the PSA architecture.
+    string other_match_type = 6;
+  }
+  // Documentation of the match field
+  Documentation doc = 7;
+  repeated string annotations = 8;
+  // Optional. If present, the location of `annotations[i]` is given by
+  // `annotation_locations[i]`.
+  repeated StructuredAnnotation structured_annotations = 9;
+  repeated SourceLocation annotation_locations = 10;
+}
+
+// used to list all possible unions in a Table
+message UnionRef {
+  uint32 id = 1;
+  enum Scope {
+    TABLE_AND_DEFAULT = 0;
+    TABLE_ONLY = 1;
+    DEFAULT_ONLY = 2;
+  }
+  Scope scope = 3;
+  repeated string annotations = 2;
+  // Optional. If present, the location of `annotations[i]` is given by
+  // `annotation_locations[i]`.
+  repeated SourceLocation annotation_locations = 5;
+  repeated StructuredAnnotation structured_annotations = 4;
+}
+
+message Union {
+  Preamble preamble = 1;
+  message Param {
+    uint32 id = 1;
+    string name = 2;
+    bool repeated = 3;
+    repeated string annotations = 4;
+    GenericDataTypeSpec type_spec = 5;
+    // Documentation of the Param
+    Documentation doc = 6;
+    repeated StructuredAnnotation structured_annotations = 7;
+    // Optional. If present, the location of `annotations[i]` is given by
+    // `annotation_locations[i]`.
+    repeated SourceLocation annotation_locations = 8;
+  }
+  repeated Param params = 2;
+}
+
+// All Tables of one type will be grouped in one message.
+message GenericTable {
+  uint32 generic_table_type_id = 1;
+  string generic_table_type_name = 2;
+  repeated string generic_table_properties = 3
+  repeated GenericTableInstance instances = 4;
+}
+
+message GenericTableInstance {
+  Preamble preamble = 1;
+  repeated GenericMatchField generic_match_fields = 2;
+  repeated UnionRef union_refs = 3;
+  // 0 (default value) means that the table does not have a const default action
+  uint32 const_default_union_id= 4;
+  int64 size = 5;  // max number of entries in table
+  // architecture-specific table properties which are not part of the core P4
+  // language or of the PSA architecture.
+  google.protobuf.Any other_properties = 100;
+}
+
+////// End: GenericTables