diff --git a/.github/workflows/vcs.yml b/.github/workflows/vcs.yml
index 82b9dcf76..708cac92b 100644
--- a/.github/workflows/vcs.yml
+++ b/.github/workflows/vcs.yml
@@ -45,7 +45,7 @@ jobs:
           nix build '.#t1.${{ matrix.config }}.ip.vcs-emu' --impure --no-link --cores 64
       - name: "Build all testcases"
         run: |
-          nix build ".#t1.${{ matrix.config }}.cases.all" --max-jobs auto --no-link --cores 64
+          nix build ".#t1.${{ matrix.config }}.ip.cases.all" --max-jobs auto --no-link --cores 64
 
   gen-matrix:
     name: "Prepare for running testcases"
diff --git a/.github/workflows/verilator.yml b/.github/workflows/verilator.yml
index d839cef20..339cccc43 100644
--- a/.github/workflows/verilator.yml
+++ b/.github/workflows/verilator.yml
@@ -34,7 +34,7 @@ jobs:
       - name: "Build all testcases"
         run: |
           # Build testcases with vlen 1024 and vlen 4096
-          nix build ".#t1.${{ matrix.config }}.cases.all" --max-jobs auto -L --no-link --cores 64
+          nix build ".#t1.${{ matrix.config }}.ip.cases.all" --max-jobs auto -L --no-link --cores 64
 
   gen-matrix:
     name: "Prepare for running testcases"
@@ -91,4 +91,4 @@ jobs:
         run: |
           nix run ".#ci-helper" -- postCI --failed-tests-file-path ./failed-tests.md --cycle-update-file-path ./cycle-update.md
           cat ./failed-tests.md >> $GITHUB_STEP_SUMMARY
-          cat ./cycle-update.md >> $GITHUB_STEP_SUMMARY
\ No newline at end of file
+          cat ./cycle-update.md >> $GITHUB_STEP_SUMMARY
diff --git a/nix/t1/default.nix b/nix/t1/default.nix
index 106ac1059..524eb7910 100644
--- a/nix/t1/default.nix
+++ b/nix/t1/default.nix
@@ -3,6 +3,7 @@
 , stdenv
 , useMoldLinker
 , newScope
+, runCommand
 
 , pkgsX86
 }:
@@ -51,16 +52,6 @@ lib.makeScope newScope
         elaborateConfigJson = configPath;
         elaborateConfig = builtins.fromJSON (lib.readFile configPath);
 
-        cases = innerSelf.callPackage ../../tests {
-          inherit (ip) verilator-emu verilator-emu-trace vcs-emu vcs-emu-trace;
-        };
-
-        # for the convenience to use x86 cases on non-x86 machines, avoiding the extra build time
-        cases-x86 =
-          if system == "x86-64-linux"
-          then self.cases
-          else pkgsX86.t1."${configName}".cases;
-
         ip = rec {
           recurseForDerivations = true;
 
@@ -80,8 +71,31 @@ lib.makeScope newScope
               "--lowering-options=verifLabels,omitVersionComment,emittedLineLength=240,locationInfoStyle=none"
             ];
           };
-          omreader = self.omreader-unwrapped.mkWrapper { inherit mlirbc; };
+
           om = innerSelf.callPackage ./om.nix { inherit mlirbc; };
+          omreader = self.omreader-unwrapped.mkWrapper { inherit mlirbc; };
+
+          emu-om = innerSelf.callPackage ./om.nix { inherit emu-mlirbc; };
+          emu-omreader = self.omreader-unwrapped.mkWrapper { inherit emu-mlirbc; };
+          omGet = args: lib.fileContents (runCommand "get-${args}" { } ''
+            ${emu-omreader}/bin/omreader ${args} > $out
+          '');
+          rtlDesignMetadata = {
+            march = omGet "march";
+            extensions = builtins.fromJSON (omGet "extensionsJson");
+            vlen = omGet "vlen";
+            dlen = omGet "dlen";
+          };
+
+          cases = innerSelf.callPackage ../../tests {
+            inherit (ip) verilator-emu verilator-emu-trace vcs-emu vcs-emu-trace;
+          };
+
+          # for the convenience to use x86 cases on non-x86 machines, avoiding the extra build time
+          cases-x86 =
+            if system == "x86-64-linux"
+            then self.cases
+            else pkgsX86.t1."${configName}".cases;
 
           emu-elaborate = innerSelf.callPackage ./elaborate.nix { target = "ipemu"; };
           emu-mlirbc = innerSelf.callPackage ./mlirbc.nix { elaborate = emu-elaborate; };
diff --git a/script/ci/src/Main.scala b/script/ci/src/Main.scala
index 8564ce6b2..50add27c3 100644
--- a/script/ci/src/Main.scala
+++ b/script/ci/src/Main.scala
@@ -162,8 +162,8 @@ object Main:
 
         val testAttr = testType.toLowerCase() match
           case "verilator" =>
-            s".#t1.$config.cases.$caseName.emu-result.with-offline"
-          case "vcs" => s".#t1.$config.cases.$caseName.emu-result.with-vcs"
+            s".#t1.$config.ip.cases.$caseName.emu-result.with-offline"
+          case "vcs" => s".#t1.$config.ip.cases.$caseName.emu-result.with-vcs"
           case _     => Logger.fatal(s"Invalid test type ${testType}")
         val testResultPath =
           try
@@ -186,7 +186,7 @@ object Main:
           os.read(testResultPath / "offline-check-status").trim() == "0"
         if !testSuccess then
           Logger.error(s"Offline check FAILED for $caseName ($config)")
-          allFailedTest :+ s"t1.$config.cases.$caseName"
+          allFailedTest :+ s"t1.$config.ip.cases.$caseName"
         else
           Logger.info(s"Offline check PASS for $caseName ($config)")
           allFailedTest
@@ -268,8 +268,8 @@ object Main:
         Logger.info("Fetching CI results")
         val resultAttr = emuType.toLowerCase() match
           case "verilator" =>
-            s".#t1.$config.cases._allEmuResult"
-          case "vcs" => s".#t1.$config.cases._allVCSEmuResult"
+            s".#t1.$config.ip.cases._allEmuResult"
+          case "vcs" => s".#t1.$config.ip.cases._allVCSEmuResult"
           case _     => Logger.fatal(s"Invalid test type ${emuType}")
         val emuResultPath = os.Path(nixResolvePath(
           resultAttr,
@@ -359,7 +359,7 @@ object Main:
 
     import scala.util.chaining._
     val testPlans: Seq[String] = emulatorConfigs.flatMap: configName =>
-      val allCasesPath = nixResolvePath(s".#t1.$configName.cases.all")
+      val allCasesPath = nixResolvePath(s".#t1.$configName.ip.cases.all")
       os.walk(os.Path(allCasesPath) / "configs")
         .filter: path =>
           path.ext == "json"
diff --git a/tests/asm/default.nix b/tests/asm/default.nix
index 4bd751df8..debd78f5c 100644
--- a/tests/asm/default.nix
+++ b/tests/asm/default.nix
@@ -3,6 +3,7 @@
 , makeBuilder
 , findAndBuild
 , t1main
+, getTestRequiredFeatures
 }:
 
 let
@@ -13,6 +14,7 @@ let
 
       src = sourcePath;
 
+      featuresRequired = getTestRequiredFeatures sourcePath;
       isFp = lib.pathExists (lib.path.append sourcePath "isFp");
 
       buildPhase = ''
@@ -29,5 +31,5 @@ let
       meta.description = "test case '${caseName}', written in C assembly";
     };
 in
-  findAndBuild ./. build
+findAndBuild ./. build
 
diff --git a/tests/asm/fpsmoke/features-required.json b/tests/asm/fpsmoke/features-required.json
new file mode 100644
index 000000000..d07cb17dc
--- /dev/null
+++ b/tests/asm/fpsmoke/features-required.json
@@ -0,0 +1 @@
+["float"]
diff --git a/tests/asm/fpsmoke/isFp b/tests/asm/fpsmoke/isFp
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/builder.nix b/tests/builder.nix
index 7016042aa..f250a8b13 100644
--- a/tests/builder.nix
+++ b/tests/builder.nix
@@ -2,9 +2,7 @@
 { stdenv
 , lib
 , jq
-, elaborateConfig
-, isFp
-, vLen
+, rtlDesignMetadata
 
 , makeEmuResult
 }:
@@ -28,22 +26,17 @@ let
 
     CC = "${stdenv.targetPlatform.config}-cc";
 
-    NIX_CFLAGS_COMPILE =
-      let
-        march = (if isFp then "rv32gc_zve32f" else "rv32gc_zve32x")
-          + "_zvl${toString (lib.min 1024 vLen)}b";
-      in
-      [
-        "-mabi=ilp32f"
-        "-march=${march}"
-        "-mno-relax"
-        "-static"
-        "-mcmodel=medany"
-        "-fvisibility=hidden"
-        "-fno-PIC"
-        "-g"
-        "-O3"
-      ];
+    NIX_CFLAGS_COMPILE = [
+      "-mabi=ilp32f"
+      "-march=${rtlDesignMetadata.march}"
+      "-mno-relax"
+      "-static"
+      "-mcmodel=medany"
+      "-fvisibility=hidden"
+      "-fno-PIC"
+      "-g"
+      "-O3"
+    ];
 
     installPhase = ''
       runHook preInstall
@@ -63,7 +56,10 @@ let
 
     dontFixup = true;
 
-    passthru.emu-result = makeEmuResult caseDrv;
+    passthru = {
+      inherit rtlDesignMetadata;
+      emu-result = makeEmuResult caseDrv;
+    };
 
   } // overrides);
 in
diff --git a/tests/codegen/default.nix b/tests/codegen/default.nix
index e771efddb..84b08e3fa 100644
--- a/tests/codegen/default.nix
+++ b/tests/codegen/default.nix
@@ -2,16 +2,25 @@
 , linkerScript
 , rvv-codegen
 , makeBuilder
-, xLen
-, vLen
-, isFp
+  # Instead of testing feature is supported on TOP level,
+  # codegen case are always generated with supported code.
+, currentFeatures
 }:
 
 let
   builder = makeBuilder { casePrefix = "codegen"; };
   makeCaseName = lib.replaceStrings [ "." ] [ "_" ];
+  extraValueFromFeatures = pattern:
+    lib.last
+      (lib.splitString ":"
+        (lib.head
+          (lib.filter
+            (lib.hasPrefix pattern)
+            currentFeatures)));
+  vlen = extraValueFromFeatures "vlen";
+  xlen = extraValueFromFeatures "xlen";
 
-  build = { rawCaseName, isFp }:
+  build = { rawCaseName, passthru }:
     builder rec {
       caseName = makeCaseName rawCaseName;
 
@@ -22,14 +31,14 @@ let
 
       dontUnpack = true;
 
-      inherit isFp;
+      inherit passthru;
 
       buildPhase = ''
         runHook preBuild
 
         ${rvv-codegen}/bin/single \
-          -VLEN "${toString vLen}" \
-          -XLEN "${toString xLen}" \
+          -VLEN "${vlen}" \
+          -XLEN "${xlen}" \
           -repeat 16 \
           -testfloat3level 2 \
           -configfile ${rvv-codegen}/configs/${rawCaseName}.toml \
@@ -50,7 +59,7 @@ let
       meta.description = "test case '${caseName}' generated by codegen";
     };
 
-  buildTestsFromFile = file: { isFp ? false }:
+  buildTestsFromFile = file: passthru:
     with lib;
     let
       rawCaseNames = lib.splitString "\n" (lib.fileContents file);
@@ -59,17 +68,18 @@ let
       (map
         (rawCaseName: nameValuePair
           (makeCaseName rawCaseName)
-          (build { inherit rawCaseName isFp; })
+          (build { inherit rawCaseName passthru; })
         )
         rawCaseNames));
 
   commonTests = buildTestsFromFile ./common.txt { };
-  fpTests = buildTestsFromFile ./fp.txt { isFp = true; };
-
+  fpTests = buildTestsFromFile ./fp.txt { featuresRequired = [ "float" ]; };
+  zvbbTests = buildTestsFromFile ./zvbb.txt { featuresRequired = [ "zvbb" ]; };
+  hasFeature = feat: lib.any (f: feat == f) currentFeatures;
 in
 lib.recurseIntoAttrs (
-    if isFp
-    then commonTests // fpTests
-    else commonTests
+  commonTests //
+  lib.optionalAttrs (hasFeature "float") fpTests //
+  lib.optionalAttrs (hasFeature "zvbb") zvbbTests
 )
 
diff --git a/tests/codegen/zvbb.txt b/tests/codegen/zvbb.txt
new file mode 100644
index 000000000..77ed67621
--- /dev/null
+++ b/tests/codegen/zvbb.txt
@@ -0,0 +1,16 @@
+vandn.vv
+vandn.vx
+vbrev.v
+vbreav8.v
+vclz.v
+vcpop.v
+vctz.v
+vrev8.v
+vrol.vv
+vrol.vx
+vror.vi
+vror.vv
+vror.vx
+vwsll.vi
+vwsll.vv
+vwsll.vx
diff --git a/tests/default.nix b/tests/default.nix
index f1755c122..71b7a4173 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -1,6 +1,6 @@
 { lib
 , configName
-, elaborateConfig
+, rtlDesignMetadata
 , newScope
 , rv32-stdenv
 , runCommand
@@ -11,23 +11,43 @@
 }:
 
 let
-  extension = lib.head elaborateConfig.parameter.extensions;
-  xLen = if lib.hasInfix "ve32" extension then 32 else 64;
-  isFp = lib.hasInfix "f" extension;
-  vLen = let vLen = elaborateConfig.parameter.vLen; in
-    assert builtins.bitAnd vLen (vLen - 1) == 0;  # vLen should be power of 2
-    assert vLen >= 32;
-    vLen;
+  hasExt = cmp: lib.any (ext: cmp == (lib.toLower ext)) rtlDesignMetadata.extensions;
+
+  # Add an extra abstract layer between test case and RTL design, so that we can have clean and organized way
+  # for developer to specify their required features without the need to parse ISA string themselves.
+  currentFeatures = [
+    "vlen:${rtlDesignMetadata.vlen}"
+    "dlen:${rtlDesignMetadata.dlen}"
+    "xlen:${if (lib.hasPrefix "rv32" rtlDesignMetadata.march) then "32" else "64"}"
+  ]
+  ++ lib.optionals (hasExt "zve32f") [ "float" ]
+  ++ lib.optionals (hasExt "zvbb") [ "zvbb" ];
+
+  # isSubSetOf m n: n is subset of m
+  isSubsetOf = m: n: lib.all (x: lib.elem x m) n;
 
   scope = lib.recurseIntoAttrs (lib.makeScope newScope (casesSelf: {
     recurseForDerivations = true;
 
-    inherit xLen vLen isFp verilator-emu verilator-emu-trace vcs-emu vcs-emu-trace;
+    inherit verilator-emu verilator-emu-trace vcs-emu vcs-emu-trace rtlDesignMetadata currentFeatures;
 
     makeEmuResult = casesSelf.callPackage ./make-emu-result.nix { };
 
     makeBuilder = casesSelf.callPackage ./builder.nix { };
 
+    # Read casePath/features-required.json to get extra feature information.
+    # Like the requirement of zve32f, or requirement for higher vlen.
+    # Empty list means no extra requirement for RTL design, then the baseline zve32x will be used.
+    #
+    # TODO: check user specified features are correct or not
+    getTestRequiredFeatures = sourcePath:
+      let
+        extraFeatures = lib.path.append sourcePath "features-required.json";
+      in
+      if lib.pathExists extraFeatures then
+        builtins.fromJSON (lib.fileContents extraFeatures)
+      else [ ];
+
     findAndBuild = dir: build:
       lib.recurseIntoAttrs (lib.pipe (builtins.readDir dir) [
         # filter out all non-directory entrires and underscore-prefixed directories
@@ -43,7 +63,10 @@ let
               inherit caseName sourcePath;
             })
         )
-        (lib.filterAttrs (caseName: caseDrv: assert caseDrv ? isFp; caseDrv.isFp -> isFp))
+        (lib.filterAttrs (caseName: caseDrv:
+          assert caseDrv ? featuresRequired;
+          # Test the case required extensions is supported by rtl design
+          isSubsetOf currentFeatures caseDrv.featuresRequired))
       ]);
     t1main = ./t1_main.S;
     linkerScript = ./t1.ld;
@@ -69,10 +92,12 @@ let
   # This allows Nix to resolve the path only once, while still pulling all tests into the local Nix store.
   _allEmuResult =
     let
-      testPlan = builtins.fromJSON (lib.readFile ../.github/cases/${configName}/default.json);
+      testPlan = builtins.fromJSON
+        (lib.readFile ../.github/cases/${configName}/default.json);
       # flattern the attr set to a list of test case derivations
       # AttrSet (AttrSet Derivation) -> List Derivation
-      allCases = lib.filter (val: lib.isDerivation val && lib.hasAttr val.pname testPlan)
+      allCases = lib.filter
+        (val: lib.isDerivation val && lib.hasAttr val.pname testPlan)
         (lib.concatLists (map lib.attrValues (lib.attrValues scopeStripped)));
       script = ''
         mkdir -p $out
@@ -86,7 +111,10 @@ let
         '')
         allCases);
     in
-    runCommand "catch-${configName}-all-emu-result-for-ci" { } script;
+    runCommand
+      "catch-${configName}-all-emu-result-for-ci"
+      { }
+      script;
 
   _allVCSEmuResult =
     let
@@ -109,7 +137,8 @@ let
 
   all =
     let
-      allCases = lib.filter lib.isDerivation
+      allCases = lib.filter
+        lib.isDerivation
         (lib.concatLists (map lib.attrValues (lib.attrValues scopeStripped)));
       script = ''
         mkdir -p $out/configs
@@ -121,6 +150,9 @@ let
         '')
         allCases);
     in
-    runCommand "build-all-testcases" { } script;
+    runCommand
+      "build-all-testcases"
+      { }
+      script;
 in
 lib.recurseIntoAttrs (scopeStripped // { inherit all _allEmuResult _allVCSEmuResult; })
diff --git a/tests/intrinsic/linear_normalization/features-required.json b/tests/intrinsic/linear_normalization/features-required.json
new file mode 100644
index 000000000..d07cb17dc
--- /dev/null
+++ b/tests/intrinsic/linear_normalization/features-required.json
@@ -0,0 +1 @@
+["float"]
diff --git a/tests/intrinsic/linear_normalization/isFp b/tests/intrinsic/linear_normalization/isFp
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/intrinsic/softmax/features-required.json b/tests/intrinsic/softmax/features-required.json
new file mode 100644
index 000000000..d07cb17dc
--- /dev/null
+++ b/tests/intrinsic/softmax/features-required.json
@@ -0,0 +1 @@
+["float"]
diff --git a/tests/intrinsic/softmax/isFp b/tests/intrinsic/softmax/isFp
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/mlir/default.nix b/tests/mlir/default.nix
index 6ebb29fe2..96ba1218f 100644
--- a/tests/mlir/default.nix
+++ b/tests/mlir/default.nix
@@ -1,8 +1,8 @@
-{ lib
-, linkerScript
+{ linkerScript
 , buddy-mlir
 , makeBuilder
 , findAndBuild
+, getTestRequiredFeatures
 , t1main
 }:
 
@@ -14,7 +14,7 @@ let
 
       src = sourcePath;
 
-      isFp = lib.pathExists (lib.path.append sourcePath "isFp");
+      featuresRequired = getTestRequiredFeatures sourcePath;
 
       nativeBuildInputs = [ buddy-mlir ];
 
@@ -60,4 +60,4 @@ let
       meta.description = "testcase '${caseName}', written in MLIR";
     };
 in
-  findAndBuild ./. build
+findAndBuild ./. build