riscv64,clint: associate with mtip

src/isa/riscv64/clint.c

 #include "monitor/monitor.h"
 #include "device/alarm.h"
 #include "device/map.h"
+#include "csr.h"
 
 #define CLINT_MMIO 0xa2000000
 #define CLINT_MTIMECMP (0x4000 / sizeof(clint_base[0]))
@@ -8,18 +9,23 @@
 
 static uint64_t *clint_base = NULL;
 
+static inline void update_mtip(void) {
+  mip->mtip = (clint_base[CLINT_MTIME] >= clint_base[CLINT_MTIMECMP]);
+}
+
 void clint_intr(void) {
   if (nemu_state.state == NEMU_RUNNING) {
     clint_base[CLINT_MTIME] += 0x800;
+    update_mtip();
   }
 }
 
-bool clint_query_intr(void) {
-  return clint_base[CLINT_MTIME] >= clint_base[CLINT_MTIMECMP];
+static void clint_io_handler(uint32_t offset, int len, bool is_write) {
+  update_mtip();
 }
 
 void init_clint(void) {
   clint_base = (void *)new_space(0x10000);
-  add_mmio_map("clint", CLINT_MMIO, (void *)clint_base, 0x10000, NULL);
+  add_mmio_map("clint", CLINT_MMIO, (void *)clint_base, 0x10000, clint_io_handler);
   add_alarm_handle(clint_intr);
 }