diff --git a/.github/workflows/build-linux.yml b/.github/workflows/build-linux.yml
index 4b0d5a95b32..c501670439e 100644
--- a/.github/workflows/build-linux.yml
+++ b/.github/workflows/build-linux.yml
@@ -143,7 +143,6 @@ jobs:
           --with-gtest=${{ steps.gtest.outputs.path }}
           --with-zlib=system
           --with-jmod-compress=zip-1
-          --disable-jvm-feature-shenandoahgc
           --with-external-symbols-in-bundles=none
           --with-native-debug-symbols-level=1
           ${{ inputs.extra-conf-options }} ${{ inputs.configure-arguments }} || (
diff --git a/.github/workflows/build-macos.yml b/.github/workflows/build-macos.yml
index 31c96595a7b..435576f4afd 100644
--- a/.github/workflows/build-macos.yml
+++ b/.github/workflows/build-macos.yml
@@ -110,7 +110,6 @@ jobs:
           --with-gtest=${{ steps.gtest.outputs.path }}
           --with-zlib=system
           --with-jmod-compress=zip-1
-          --disable-jvm-feature-shenandoahgc
           --with-external-symbols-in-bundles=none
           --with-native-debug-symbols-level=1
           ${{ inputs.extra-conf-options }} ${{ inputs.configure-arguments }} || (
diff --git a/.github/workflows/build-windows.yml b/.github/workflows/build-windows.yml
index 91748805389..3bb50a137ec 100644
--- a/.github/workflows/build-windows.yml
+++ b/.github/workflows/build-windows.yml
@@ -134,7 +134,6 @@ jobs:
           --with-gtest=${{ steps.gtest.outputs.path }}
           --with-msvc-toolset-version=${{ inputs.msvc-toolset-version }}
           --with-jmod-compress=zip-1
-          --disable-jvm-feature-shenandoahgc
           --with-external-symbols-in-bundles=none
           ${{ inputs.extra-conf-options }} ${{ inputs.configure-arguments }} || (
           echo "Dumping config.log:" &&
diff --git a/src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp b/src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp
index bc3650e3e24..cfcd6f6759a 100644
--- a/src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp
+++ b/src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp
@@ -887,7 +887,7 @@ bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) {
         }
   } else if (src_type->isa_aryptr()) {
     BasicType src_elem = src_type->isa_aryptr()->elem()->array_element_basic_type();
-    if (is_reference_type(src_elem, true)) {
+    if (is_reference_type(src_elem, true) && !src_type->is_flat()) {
       return true;
     }
   } else {
diff --git a/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp b/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp
index 89b8742c706..4ebf369d98b 100644
--- a/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp
+++ b/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp
@@ -51,6 +51,7 @@ bool ShenandoahBarrierC2Support::expand(Compile* C, PhaseIterGVN& igvn) {
     C->clear_major_progress();
     PhaseIdealLoop::optimize(igvn, LoopOptsShenandoahExpand);
     if (C->failing()) return false;
+    C->clear_major_progress(); // TODO: Why this is only needed for Valhalla?
     C->process_for_post_loop_opts_igvn(igvn);
     if (C->failing()) return false;
 
@@ -2495,6 +2496,8 @@ bool ShenandoahLoadReferenceBarrierNode::needs_barrier_impl(PhaseGVN* phase, Nod
              needs_barrier_impl(phase, n->in(3), visited);
     case Op_CreateEx:
       return false;
+    case Op_InlineType:
+      return true;
     default:
       break;
   }
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp b/src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp
index df7e263564c..8f4154cdd6c 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp
@@ -88,8 +88,11 @@ void ShenandoahMark::do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveD
       // Case 2: Object array instance and no chunk is set. Must be the first
       // time we visit it, start the chunked processing.
       do_chunked_array_start<T>(q, cl, obj, weak);
+    } else if (obj->is_flatArray()) {
+      // Case 3: Flat array instance, all elements are embedded.
+      obj->oop_iterate(cl);
     } else {
-      // Case 3: Primitive array. Do nothing, no oops there. We use the same
+      // Case 4: Primitive array. Do nothing, no oops there. We use the same
       // performance tweak TypeArrayKlass::oop_oop_iterate_impl is using:
       // We skip iterating over the klass pointer since we know that
       // Universe::TypeArrayKlass never moves.
@@ -153,8 +156,8 @@ inline void ShenandoahMark::count_liveness(ShenandoahLiveData* live_data, oop ob
 
 template <class T>
 inline void ShenandoahMark::do_chunked_array_start(ShenandoahObjToScanQueue* q, T* cl, oop obj, bool weak) {
-  assert(obj->is_refArray(), "expect object array");
-  objArrayOop array = objArrayOop(obj);
+  assert(obj->is_refArray(), "expect ref array");
+  refArrayOop array = refArrayOop(obj);
   int len = array->length();
 
   // Mark objArray klass metadata
@@ -220,8 +223,8 @@ inline void ShenandoahMark::do_chunked_array_start(ShenandoahObjToScanQueue* q,
 
 template <class T>
 inline void ShenandoahMark::do_chunked_array(ShenandoahObjToScanQueue* q, T* cl, oop obj, int chunk, int pow, bool weak) {
-  assert(obj->is_refArray(), "expect object array");
-  objArrayOop array = objArrayOop(obj);
+  assert(obj->is_refArray(), "expect ref array");
+  refArrayOop array = refArrayOop(obj);
 
   // Split out tasks, as suggested in ShenandoahMarkTask docs. Avoid pushing tasks that
   // are known to start beyond the array.
diff --git a/src/hotspot/share/opto/graphKit.cpp b/src/hotspot/share/opto/graphKit.cpp
index 38c02182d46..0ca75da967a 100644
--- a/src/hotspot/share/opto/graphKit.cpp
+++ b/src/hotspot/share/opto/graphKit.cpp
@@ -32,6 +32,7 @@
 #include "compiler/compileLog.hpp"
 #include "gc/shared/barrierSet.hpp"
 #include "gc/shared/c2/barrierSetC2.hpp"
+#include "gc/shared/gc_globals.hpp"
 #include "interpreter/interpreter.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/flatArrayKlass.hpp"
@@ -3720,7 +3721,7 @@ Node* GraphKit::gen_checkcast(Node* obj, Node* superklass, Node** failure_contro
           assert(safe_for_replace, "must be");
           obj = null_check(obj);
         }
-        assert(stopped() || !toop->is_inlinetypeptr() || obj->is_InlineType(), "should have been scalarized");
+        assert(stopped() || !toop->is_inlinetypeptr() || obj->is_InlineType() || UseShenandoahGC, "should have been scalarized");
         return obj;
       case Compile::SSC_always_false:
         if (null_free) {
diff --git a/src/hotspot/share/opto/idealKit.cpp b/src/hotspot/share/opto/idealKit.cpp
index 7d45fb770ef..78d68c6de2e 100644
--- a/src/hotspot/share/opto/idealKit.cpp
+++ b/src/hotspot/share/opto/idealKit.cpp
@@ -312,7 +312,7 @@ Node* IdealKit::delay_transform(Node* n) {
 Node* IdealKit::new_cvstate() {
   uint sz = _var_ct + first_var;
   Node* state = new Node(sz);
-  C->record_for_igvn(state);
+  gvn().record_for_igvn(state);
   return state;
 }
 
@@ -321,7 +321,9 @@ Node* IdealKit::copy_cvstate() {
   Node* ns = new_cvstate();
   for (uint i = 0; i < ns->req(); i++) ns->init_req(i, _cvstate->in(i));
   // We must clone memory since it will be updated as we do stores.
-  ns->set_req(TypeFunc::Memory, MergeMemNode::make(ns->in(TypeFunc::Memory)));
+  Node* mem = MergeMemNode::make(ns->in(TypeFunc::Memory));
+  gvn().record_for_igvn(mem);
+  ns->set_req(TypeFunc::Memory, mem);
   return ns;
 }
 
diff --git a/src/hotspot/share/opto/output.cpp b/src/hotspot/share/opto/output.cpp
index 889af816cc6..36701bae6b6 100644
--- a/src/hotspot/share/opto/output.cpp
+++ b/src/hotspot/share/opto/output.cpp
@@ -3183,8 +3183,14 @@ void PhaseOutput::init_scratch_buffer_blob(int const_size) {
     if (C->has_scalarized_args()) {
       // Inline type entry points (MachVEPNodes) require lots of space for GC barriers and oop verification
       // when loading object fields from the buffered argument. Increase scratch buffer size accordingly.
+      int barrier_size = 7;
+      DEBUG_ONLY(barrier_size += 37;)
+      if (UseShenandoahGC) {
+        barrier_size += 250;
+      } else if (UseZGC) {
+        barrier_size += 200;
+      }
       ciMethod* method = C->method();
-      int barrier_size = UseZGC ? 200 : (7 DEBUG_ONLY(+ 37));
       int arg_num = 0;
       if (!method->is_static()) {
         if (method->is_scalarized_arg(arg_num)) {
diff --git a/test/hotspot/jtreg/TEST.groups b/test/hotspot/jtreg/TEST.groups
index 81971879f03..ef7e5fc6c1e 100644
--- a/test/hotspot/jtreg/TEST.groups
+++ b/test/hotspot/jtreg/TEST.groups
@@ -338,6 +338,8 @@ tier1_gc_shenandoah = \
 tier2_gc_shenandoah = \
   runtime/MemberName/MemberNameLeak.java \
   runtime/CompressedOops/UseCompressedOops.java \
+  runtime/valhalla/inlinetypes/FlatArrayCopyingTest.java \
+  runtime/valhalla/inlinetypes/InlineOops.java \
   gc/TestHumongousReferenceObject.java \
   gc/TestSystemGC.java \
   gc/arguments/TestDisableDefaultGC.java \
diff --git a/test/hotspot/jtreg/runtime/valhalla/inlinetypes/FlatArrayCopyingTest.java b/test/hotspot/jtreg/runtime/valhalla/inlinetypes/FlatArrayCopyingTest.java
index 74b7d56f3ba..41f4c6e0c22 100644
--- a/test/hotspot/jtreg/runtime/valhalla/inlinetypes/FlatArrayCopyingTest.java
+++ b/test/hotspot/jtreg/runtime/valhalla/inlinetypes/FlatArrayCopyingTest.java
@@ -29,6 +29,7 @@
  * @bug 8370479
  * @enablePreview
  * @requires vm.flagless
+ * @requires vm.gc.Serial
  * @library /test/lib /
  * @modules java.base/jdk.internal.value
             java.management
@@ -47,6 +48,7 @@
  * @bug 8370479
  * @enablePreview
  * @requires vm.flagless
+ * @requires vm.gc.Parallel
  * @library /test/lib /
  * @modules java.base/jdk.internal.value
             java.management
@@ -65,6 +67,7 @@
  * @bug 8370479
  * @enablePreview
  * @requires vm.flagless
+ * @requires vm.gc.G1
  * @library /test/lib /
  * @modules java.base/jdk.internal.value
             java.management
@@ -78,6 +81,27 @@
                                   runtime.valhalla.inlinetypes.FlatArrayCopyingTest
  */
 
+/*
+ * @test id=shenandoah
+ * @summary Ensures that value arrays can get arraycopied properly with Shenandoah.
+ *          This test will likely crash if that is not the case.
+ * @bug 8370479
+ * @enablePreview
+ * @requires vm.flagless
+ * @requires vm.gc.Shenandoah
+ * @library /test/lib /
+ * @modules java.base/jdk.internal.value
+            java.management
+ * @build jdk.test.whitebox.WhiteBox
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
+ * @run junit/othervm/timeout=480 -XX:+UnlockDiagnosticVMOptions
+                                  -Xint -XX:+UseShenandoahGC -XX:+UseCompressedOops -Xlog:gc*=info
+                                  -XX:ParallelGCThreads=1 -XX:ConcGCThreads=1 -XX:-UseDynamicNumberOfGCThreads
+                                  -XX:+UseCompressedClassPointers
+                                  -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+                                  runtime.valhalla.inlinetypes.FlatArrayCopyingTest
+ */
+
 package runtime.valhalla.inlinetypes;
 
 import java.util.Arrays;
diff --git a/test/hotspot/jtreg/runtime/valhalla/inlinetypes/InlineOops.java b/test/hotspot/jtreg/runtime/valhalla/inlinetypes/InlineOops.java
index 95b2485967e..caabb9f9d1d 100644
--- a/test/hotspot/jtreg/runtime/valhalla/inlinetypes/InlineOops.java
+++ b/test/hotspot/jtreg/runtime/valhalla/inlinetypes/InlineOops.java
@@ -88,6 +88,22 @@
  *                   runtime.valhalla.inlinetypes.InlineOops
  */
 
+/**
+ * @test id=Shenandoah
+ * @requires vm.gc.Shenandoah
+ * @summary Test embedding oops into Inline types
+ * @modules java.base/jdk.internal.value
+ *          java.base/jdk.internal.vm.annotation
+ * @library /test/lib /test/jdk/java/lang/invoke/common
+ * @enablePreview
+ * @requires vm.flagless
+ * @compile Person.java InlineOops.java
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
+ * @run main/othervm -XX:+UseShenandoahGC -Xmx128m -XX:+UseFieldFlattening
+ *                   -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+ *                   runtime.valhalla.inlinetypes.InlineOops
+ */
+
 /**
  * @test id=Z
  * @requires vm.gc.Z