diff --git a/src/arch/riscv/faults.hh b/src/arch/riscv/faults.hh
index 1bc671ef26..e66476727c 100644
--- a/src/arch/riscv/faults.hh
+++ b/src/arch/riscv/faults.hh
@@ -93,7 +93,11 @@ enum ExceptionCode : uint64_t
     INT_EXT_USER = 8,
     INT_EXT_SUPER = 9,
     INT_EXT_MACHINE = 11,
-    NumInterruptTypes
+    NumInterruptTypes,
+    // INT_NMI does not exist in the spec, it's a modeling artifact for NMI. We
+    // intentionally set it to be NumInterruptTypes so it can never conflict
+    // with any real INT_NUM in used.
+    INT_NMI = NumInterruptTypes,
 };
 
 enum class FaultType
diff --git a/src/arch/riscv/interrupts.hh b/src/arch/riscv/interrupts.hh
index 88b7b2e5a4..f10c5f386a 100644
--- a/src/arch/riscv/interrupts.hh
+++ b/src/arch/riscv/interrupts.hh
@@ -141,14 +141,22 @@ class Interrupts : public BaseInterrupts
     post(int int_num, int index)
     {
         DPRINTF(Interrupt, "Interrupt %d:%d posted\n", int_num, index);
-        ip[int_num] = true;
+        if (int_num != INT_NMI) {
+            ip[int_num] = true;
+        } else {
+            postNMI();
+        }
     }
 
     void
     clear(int int_num, int index)
     {
         DPRINTF(Interrupt, "Interrupt %d:%d cleared\n", int_num, index);
-        ip[int_num] = false;
+        if (int_num != INT_NMI) {
+            ip[int_num] = false;
+        } else {
+            clearNMI();
+        }
     }
 
     void postNMI() { tc->setMiscReg(MISCREG_NMIP, 1); }
diff --git a/src/arch/riscv/isa/decoder.isa b/src/arch/riscv/isa/decoder.isa
index 7a10fa0bdb..04a36c1a8c 100644
--- a/src/arch/riscv/isa/decoder.isa
+++ b/src/arch/riscv/isa/decoder.isa
@@ -1906,7 +1906,7 @@ decode QUADRANT default Unknown::unknown() {
                                             "wfi in user mode or TW enabled",
                                             machInst);
                             }
-                            // don't do anything for now
+                            xc->tcBase()->quiesce();
                         }}, No_OpClass);
                     }
                     0x9: sfence_vma({{