hv: add default handlers for PIO/MMIO access

Add the default handlers for PIO and MMIO access which returns all
FFs on read and discards write. These default handlers are registered
when SOS VM or pre-launched VM is created.

v3 -> v4:
- use single layer if in hv_emulate_pio
- change the implementation of pio_default_read

v2 -> v3:
- use runtime vm type instead of CONFIG_PARTITION_MODE
- revise the pio/mmio emulation functions
- revise the pio/mmio default read functions according to MISRA C
- revise the commit message

v1 -> v2:
- add default handlers members in struct acrn_vm and add interfaces
  to register default handlers for PIO and MMIO.

Tracked-On: #2860
Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/include/arch/x86/guest/io_emul.h

@@ -84,4 +84,17 @@ int32_t register_mmio_emulation_handler(struct acrn_vm *vm,
 	hv_mem_io_handler_t read_write, uint64_t start,
 	uint64_t end, void *handler_private_data);
 
+/**
+ * @brief Register port I/O default handler
+ *
+ * @param vm      The VM to which the port I/O handlers are registered
+ */
+void register_pio_default_emulation_handler(struct acrn_vm *vm);
+
+/**
+ * @brief Register MMIO default handler
+ *
+ * @param vm The VM to which the MMIO handler is registered
+ */
+void register_mmio_default_emulation_handler(struct acrn_vm *vm);
 #endif /* IO_EMUL_H */