Add API to check whether a physical address is I/O address

This API will be used in the following patch.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

cpu-common.h

@@ -71,6 +71,10 @@ void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
 void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque));
 void cpu_unregister_map_client(void *cookie);
 
+#ifndef CONFIG_USER_ONLY
+bool cpu_physical_memory_is_io(target_phys_addr_t phys_addr);
+#endif
+
 /* Coalesced MMIO regions are areas where write operations can be reordered.
  * This usually implies that write operations are side-effect free.  This allows
  * batching which can make a major impact on performance when using

exec.c

@@ -4336,3 +4336,15 @@ bool virtio_is_big_endian(void)
 }
 
 #endif
+
+#ifndef CONFIG_USER_ONLY
+bool cpu_physical_memory_is_io(target_phys_addr_t phys_addr)
+{
+    MemoryRegionSection *section;
+
+    section = phys_page_find(phys_addr >> TARGET_PAGE_BITS);
+
+    return !(memory_region_is_ram(section->mr) ||
+             memory_region_is_romd(section->mr));
+}
+#endif