diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index af0c52a484..3abf52453c 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -213,17 +213,19 @@ void csr_write_helper(CPURISCVState *env, target_ulong val_to_write,
         break;
     }
     case CSR_MINSTRET:
-        qemu_log_mask(LOG_UNIMP, "CSR_MINSTRET: write not implemented");
-        goto do_illegal;
+        /* minstret is WARL so unsupported writes are ignored */
+        break;
     case CSR_MCYCLE:
-        qemu_log_mask(LOG_UNIMP, "CSR_MCYCLE: write not implemented");
-        goto do_illegal;
+        /* mcycle is WARL so unsupported writes are ignored */
+        break;
+#if defined(TARGET_RISCV32)
     case CSR_MINSTRETH:
-        qemu_log_mask(LOG_UNIMP, "CSR_MINSTRETH: write not implemented");
-        goto do_illegal;
+        /* minstreth is WARL so unsupported writes are ignored */
+        break;
     case CSR_MCYCLEH:
-        qemu_log_mask(LOG_UNIMP, "CSR_MCYCLEH: write not implemented");
-        goto do_illegal;
+        /* mcycleh is WARL so unsupported writes are ignored */
+        break;
+#endif
     case CSR_MUCOUNTEREN:
         if (env->priv_ver <= PRIV_VERSION_1_09_1) {
             env->scounteren = val_to_write;
@@ -337,10 +339,9 @@ void csr_write_helper(CPURISCVState *env, target_ulong val_to_write,
     case CSR_MBADADDR:
         env->mbadaddr = val_to_write;
         break;
-    case CSR_MISA: {
-        qemu_log_mask(LOG_UNIMP, "CSR_MISA: misa writes not supported");
-        goto do_illegal;
-    }
+    case CSR_MISA:
+        /* misa is WARL so unsupported writes are ignored */
+        break;
     case CSR_PMPCFG0:
     case CSR_PMPCFG1:
     case CSR_PMPCFG2: