diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -108,6 +108,14 @@
 
 bool AArch64TTIImpl::areInlineCompatible(const Function *Caller,
                                          const Function *Callee) const {
+  auto CallerAttrs = SMEAttrs::getFromFunction(*Caller);
+  auto CalleeAttrs = SMEAttrs::getFromFunction(*Callee);
+  if (CallerAttrs.requiresSMChange(CalleeAttrs,
+                                   /*BodyOverridesInterface=*/true) ||
+      CallerAttrs.requiresLazySave(CalleeAttrs) ||
+      CalleeAttrs.hasNewZAInterface())
+    return false;
+
   const TargetMachine &TM = getTLI()->getTargetMachine();
 
   const FeatureBitset &CallerBits =
diff --git a/llvm/test/Transforms/Inline/AArch64/sme-pstatesm-attrs.ll b/llvm/test/Transforms/Inline/AArch64/sme-pstatesm-attrs.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Inline/AArch64/sme-pstatesm-attrs.ll
@@ -0,0 +1,377 @@
+; RUN: opt < %s -mtriple=aarch64-unknown-linux-gnu -mattr=+sme -S -inline | FileCheck %s
+
+declare void @inlined_body() "aarch64_pstate_sm_compatible";
+
+;
+; Define some functions that will be called by the functions below.
+; These just call a '...body()' function. If we see the call to one of
+; these functions being replaced by '...body()', then we know it has been
+; inlined.
+;
+
+define void @normal_callee() {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @streaming_callee() "aarch64_pstate_sm_enabled" {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @locally_streaming_callee() "aarch64_pstate_sm_body" {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @streaming_compatible_callee() "aarch64_pstate_sm_compatible" {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @streaming_compatible_locally_streaming_callee() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+;
+; Now test that inlining only happens when their streaming modes match.
+; Test for a number of combinations, where:
+; N       Normal-interface (PSTATE.SM=0 on entry/exit)
+; S       Streaming-interface (PSTATE.SM=1 on entry/exit)
+; SC      Streaming-compatible interface
+;         (PSTATE.SM=0 or 1, unchanged on exit)
+; N + B   Normal-interface, streaming body
+;         (PSTATE.SM=0 on entry/exit, but 1 within the body of the function)
+; SC + B  Streaming-compatible-interface, streaming body
+;         (PSTATE.SM=0 or 1 on entry, unchanged on exit,
+;          but guaranteed to be 1 within the body of the function)
+
+; [x] N  -> N
+; [ ] N  -> S
+; [ ] N  -> SC
+; [ ] N  -> N + B
+; [ ] N  -> SC + B
+define void @normal_caller_normal_callee_inline() {
+; CHECK-LABEL: @normal_caller_normal_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @normal_callee()
+  ret void
+}
+
+; [ ] N  -> N
+; [x] N  -> S
+; [ ] N  -> SC
+; [ ] N  -> N + B
+; [ ] N  -> SC + B
+define void @normal_caller_streaming_callee_dont_inline() {
+; CHECK-LABEL: @normal_caller_streaming_callee_dont_inline(
+; CHECK: call void @streaming_callee()
+entry:
+  call void @streaming_callee()
+  ret void
+}
+
+; [ ] N  -> N
+; [ ] N  -> S
+; [x] N  -> SC
+; [ ] N  -> N + B
+; [ ] N  -> SC + B
+define void @normal_caller_streaming_compatible_callee_inline() {
+; CHECK-LABEL: @normal_caller_streaming_compatible_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_callee()
+  ret void
+}
+
+; [ ] N  -> N
+; [ ] N  -> S
+; [ ] N  -> SC
+; [x] N  -> N + B
+; [ ] N  -> SC + B
+define void @normal_caller_locally_streaming_callee_dont_inline() {
+; CHECK-LABEL: @normal_caller_locally_streaming_callee_dont_inline(
+; CHECK: call void @locally_streaming_callee()
+entry:
+  call void @locally_streaming_callee()
+  ret void
+}
+
+; [ ] N  -> N
+; [ ] N  -> S
+; [ ] N  -> SC
+; [ ] N  -> N + B
+; [x] N  -> SC + B
+define void @normal_caller_streaming_compatible_locally_streaming_callee_dont_inline() {
+; CHECK-LABEL: @normal_caller_streaming_compatible_locally_streaming_callee_dont_inline(
+; CHECK: call void @streaming_compatible_locally_streaming_callee()
+entry:
+  call void @streaming_compatible_locally_streaming_callee()
+  ret void
+}
+
+; [x] S  -> N
+; [ ] S  -> S
+; [ ] S  -> SC
+; [ ] S  -> N + B
+; [ ] S  -> SC + B
+define void @streaming_caller_normal_callee_dont_inline() "aarch64_pstate_sm_enabled" {
+; CHECK-LABEL: @streaming_caller_normal_callee_dont_inline(
+; CHECK: call void @normal_callee()
+entry:
+  call void @normal_callee()
+  ret void
+}
+
+; [ ] S  -> N
+; [x] S  -> S
+; [ ] S  -> SC
+; [ ] S  -> N + B
+; [ ] S  -> SC + B
+define void @streaming_caller_streaming_callee_inline() "aarch64_pstate_sm_enabled" {
+; CHECK-LABEL: @streaming_caller_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_callee()
+  ret void
+}
+
+; [ ] S  -> N
+; [ ] S  -> S
+; [x] S  -> SC
+; [ ] S  -> N + B
+; [ ] S  -> SC + B
+define void @streaming_caller_streaming_compatible_callee_inline() "aarch64_pstate_sm_enabled" {
+; CHECK-LABEL: @streaming_caller_streaming_compatible_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_callee()
+  ret void
+}
+
+; [ ] S  -> N
+; [ ] S  -> S
+; [ ] S  -> SC
+; [x] S  -> N + B
+; [ ] S  -> SC + B
+define void @streaming_caller_locally_streaming_callee_inline() "aarch64_pstate_sm_enabled" {
+; CHECK-LABEL: @streaming_caller_locally_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @locally_streaming_callee()
+  ret void
+}
+
+; [ ] S  -> N
+; [ ] S  -> S
+; [ ] S  -> SC
+; [ ] S  -> N + B
+; [x] S  -> SC + B
+define void @streaming_caller_streaming_compatible_locally_streaming_callee_inline() "aarch64_pstate_sm_enabled" {
+; CHECK-LABEL: @streaming_caller_streaming_compatible_locally_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_locally_streaming_callee()
+  ret void
+}
+
+; [x] N + B -> N
+; [ ] N + B -> S
+; [ ] N + B -> SC
+; [ ] N + B -> N + B
+; [ ] N + B -> SC + B
+define void @locally_streaming_caller_normal_callee_dont_inline() "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @locally_streaming_caller_normal_callee_dont_inline(
+; CHECK: call void @normal_callee()
+entry:
+  call void @normal_callee()
+  ret void
+}
+
+; [ ] N + B -> N
+; [x] N + B -> S
+; [ ] N + B -> SC
+; [ ] N + B -> N + B
+; [ ] N + B -> SC + B
+define void @locally_streaming_caller_streaming_callee_inline() "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @locally_streaming_caller_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_callee()
+  ret void
+}
+
+; [ ] N + B -> N
+; [ ] N + B -> S
+; [x] N + B -> SC
+; [ ] N + B -> N + B
+; [ ] N + B -> SC + B
+define void @locally_streaming_caller_streaming_compatible_callee_inline() "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @locally_streaming_caller_streaming_compatible_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_callee()
+  ret void
+}
+
+; [ ] N + B -> N
+; [ ] N + B -> S
+; [ ] N + B -> SC
+; [x] N + B -> N + B
+; [ ] N + B -> SC + B
+define void @locally_streaming_caller_locally_streaming_callee_inline() "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @locally_streaming_caller_locally_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @locally_streaming_callee()
+  ret void
+}
+
+; [ ] N + B -> N
+; [ ] N + B -> S
+; [ ] N + B -> SC
+; [ ] N + B -> N + B
+; [x] N + B -> SC + B
+define void @locally_streaming_caller_streaming_compatible_locally_streaming_callee_inline() "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @locally_streaming_caller_streaming_compatible_locally_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_locally_streaming_callee()
+  ret void
+}
+
+; [x] SC -> N
+; [ ] SC -> S
+; [ ] SC -> SC
+; [ ] SC -> N + B
+; [ ] SC -> SC + B
+define void @streaming_compatible_caller_normal_callee_dont_inline() "aarch64_pstate_sm_compatible" {
+; CHECK-LABEL: @streaming_compatible_caller_normal_callee_dont_inline(
+; CHECK: call void @normal_callee()
+entry:
+  call void @normal_callee()
+  ret void
+}
+
+; [ ] SC -> N
+; [x] SC -> S
+; [ ] SC -> SC
+; [ ] SC -> N + B
+; [ ] SC -> SC + B
+define void @streaming_compatible_caller_streaming_callee_dont_inline() "aarch64_pstate_sm_compatible" {
+; CHECK-LABEL: @streaming_compatible_caller_streaming_callee_dont_inline(
+; CHECK: call void @streaming_callee()
+entry:
+  call void @streaming_callee()
+  ret void
+}
+
+; [ ] SC -> N
+; [ ] SC -> S
+; [x] SC -> SC
+; [ ] SC -> N + B
+; [ ] SC -> SC + B
+define void @streaming_compatible_caller_streaming_compatible_callee_inline() "aarch64_pstate_sm_compatible" {
+; CHECK-LABEL: @streaming_compatible_caller_streaming_compatible_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_callee()
+  ret void
+}
+
+; [ ] SC -> N
+; [ ] SC -> S
+; [ ] SC -> SC
+; [x] SC -> N + B
+; [ ] SC -> SC + B
+define void @streaming_compatible_caller_locally_streaming_callee_dont_inline() "aarch64_pstate_sm_compatible" {
+; CHECK-LABEL: @streaming_compatible_caller_locally_streaming_callee_dont_inline(
+; CHECK: call void @locally_streaming_callee()
+entry:
+  call void @locally_streaming_callee()
+  ret void
+}
+
+; [ ] SC -> N
+; [ ] SC -> S
+; [ ] SC -> SC
+; [ ] SC -> N + B
+; [x] SC -> SC + B
+define void @streaming_compatible_caller_streaming_compatible_locally_streaming_callee_dont_inline() "aarch64_pstate_sm_compatible" {
+; CHECK-LABEL: @streaming_compatible_caller_streaming_compatible_locally_streaming_callee_dont_inline(
+; CHECK: call void @streaming_compatible_locally_streaming_callee()
+entry:
+  call void @streaming_compatible_locally_streaming_callee()
+  ret void
+}
+; [x] SC + B -> N
+; [ ] SC + B -> S
+; [ ] SC + B -> SC
+; [ ] SC + B -> N + B
+; [ ] SC + B -> SC + B
+define void @streaming_compatible_locally_streaming_caller_normal_callee_dont_inline() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @streaming_compatible_locally_streaming_caller_normal_callee_dont_inline(
+; CHECK: call void @normal_callee()
+entry:
+  call void @normal_callee()
+  ret void
+}
+
+; [ ] SC + B -> N
+; [x] SC + B -> S
+; [ ] SC + B -> SC
+; [ ] SC + B -> N + B
+; [ ] SC + B -> SC + B
+define void @streaming_compatible_locally_streaming_caller_streaming_callee_inline() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @streaming_compatible_locally_streaming_caller_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_callee()
+  ret void
+}
+
+; [ ] SC + B -> N
+; [ ] SC + B -> S
+; [x] SC + B -> SC
+; [ ] SC + B -> N + B
+; [ ] SC + B -> SC + B
+define void @streaming_compatible_locally_streaming_caller_streaming_compatible_callee_inline() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @streaming_compatible_locally_streaming_caller_streaming_compatible_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_callee()
+  ret void
+}
+
+; [ ] SC + B -> N
+; [ ] SC + B -> S
+; [ ] SC + B -> SC
+; [x] SC + B -> N + B
+; [ ] SC + B -> SC + B
+define void @streaming_compatible_locally_streaming_caller_locally_streaming_callee_inline() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @streaming_compatible_locally_streaming_caller_locally_streaming_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @locally_streaming_callee()
+  ret void
+}
+
+; [ ] SC + B -> N
+; [ ] SC + B -> S
+; [ ] SC + B -> SC
+; [ ] SC + B -> N + B
+; [x] SC + B -> SC + B
+define void @streaming_compatible_locally_streaming_caller_and_callee_inline() "aarch64_pstate_sm_compatible" "aarch64_pstate_sm_body" {
+; CHECK-LABEL: @streaming_compatible_locally_streaming_caller_and_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @streaming_compatible_locally_streaming_callee()
+  ret void
+}
diff --git a/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll b/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll
@@ -0,0 +1,122 @@
+; RUN: opt -mtriple=aarch64-unknown-linux-gnu -mattr=+sme -S -inline < %s | FileCheck %s
+
+declare void @inlined_body()
+
+;
+; Define some functions that will be called by the functions below.
+; These just call a '...body()' function. If we see the call to one of
+; these functions being replaced by '...body()', then we know it has been
+; inlined.
+;
+
+define void @nonza_callee() {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @shared_za_callee() "aarch64_pstate_za_shared" {
+entry:
+  call void @inlined_body()
+  ret void
+}
+
+define void @new_za_callee() "aarch64_pstate_za_new" {
+  call void @inlined_body()
+  ret void
+}
+
+;
+; Now test that inlining only happens when no lazy-save is needed.
+; Test for a number of combinations, where:
+; N   Not using ZA.
+; S   Shared ZA interface
+; Z   New ZA interface
+
+; [x] N -> N
+; [ ] N -> S (This combination is invalid)
+; [ ] N -> Z
+define void @nonza_caller_nonza_callee_inline() {
+; CHECK-LABEL: @nonza_caller_nonza_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @nonza_callee()
+  ret void
+}
+
+; [ ] N -> N
+; [ ] N -> S (This combination is invalid)
+; [x] N -> Z
+define void @nonza_caller_new_za_callee_dont_inline() {
+; CHECK-LABEL: @nonza_caller_new_za_callee_dont_inline(
+; CHECK: call void @new_za_callee()
+entry:
+  call void @new_za_callee()
+  ret void
+}
+
+; [x] Z -> N
+; [ ] Z -> S
+; [ ] Z -> Z
+define void @new_za_caller_nonza_callee_dont_inline() "aarch64_pstate_za_new" {
+; CHECK-LABEL: @new_za_caller_nonza_callee_dont_inline(
+; CHECK: call void @nonza_callee()
+entry:
+  call void @nonza_callee()
+  ret void
+}
+
+; [ ] Z -> N
+; [x] Z -> S
+; [ ] Z -> Z
+define void @new_za_caller_shared_za_callee_inline() "aarch64_pstate_za_new" {
+; CHECK-LABEL: @new_za_caller_shared_za_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @shared_za_callee()
+  ret void
+}
+
+; [ ] Z -> N
+; [ ] Z -> S
+; [x] Z -> Z
+define void @new_za_caller_new_za_callee_dont_inline() "aarch64_pstate_za_new" {
+; CHECK-LABEL: @new_za_caller_new_za_callee_dont_inline(
+; CHECK: call void @new_za_callee()
+entry:
+  call void @new_za_callee()
+  ret void
+}
+
+; [x] Z -> N
+; [ ] Z -> S
+; [ ] Z -> Z
+define void @shared_za_caller_nonza_callee_dont_inline() "aarch64_pstate_za_shared" {
+; CHECK-LABEL: @shared_za_caller_nonza_callee_dont_inline(
+; CHECK: call void @nonza_callee()
+entry:
+  call void @nonza_callee()
+  ret void
+}
+
+; [ ] S -> N
+; [x] S -> Z
+; [ ] S -> S
+define void @shared_za_caller_new_za_callee_dont_inline() "aarch64_pstate_za_shared" {
+; CHECK-LABEL: @shared_za_caller_new_za_callee_dont_inline(
+; CHECK: call void @new_za_callee()
+entry:
+  call void @new_za_callee()
+  ret void
+}
+
+; [ ] S -> N
+; [ ] S -> Z
+; [x] S -> S
+define void @shared_za_caller_shared_za_callee_inline() "aarch64_pstate_za_shared" {
+; CHECK-LABEL: @shared_za_caller_shared_za_callee_inline(
+; CHECK: call void @inlined_body()
+entry:
+  call void @shared_za_callee()
+  ret void
+}