This API used for output current configuration for one specified CPU.
Currently only RISC-V frontend implements this API.

Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 cpu.c                     |  8 ++++++++
 include/exec/cpu-common.h |  1 +
 target/riscv/cpu.c        | 14 ++++++++++++++
 target/riscv/cpu.h        |  2 ++
 4 files changed, 25 insertions(+)

diff --git a/cpu.c b/cpu.c
index e1a9239d0f..03a313cd72 100644
--- a/cpu.c
+++ b/cpu.c
@@ -299,6 +299,14 @@ void list_cpus(void)
 #endif
 }
 
+void list_cpu_props(CPUState *cs)
+{
+    /* XXX: implement xxx_cpu_list_props for targets that still miss it */
+#if defined(cpu_list_props)
+    cpu_list_props(cs);
+#endif
+}
+
 #if defined(CONFIG_USER_ONLY)
 void tb_invalidate_phys_addr(hwaddr addr)
 {
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 87dc9a752c..b3160d9218 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -166,5 +166,6 @@ int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
 
 /* vl.c */
 void list_cpus(void);
+void list_cpu_props(CPUState *);
 
 #endif /* CPU_COMMON_H */
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 6b93b04453..c2f102fae1 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2226,6 +2226,20 @@ void riscv_cpu_list(void)
     g_slist_free(list);
 }
 
+void riscv_cpu_list_props(CPUState *cs)
+{
+    char *enabled_isa;
+    RISCVCPU *cpu = RISCV_CPU(cs);
+    RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(cpu);
+    ObjectClass *oc = OBJECT_CLASS(mcc);
+
+    enabled_isa = riscv_isa_string(RISCV_CPU(cs));
+    qemu_printf("Enabled extensions:\n");
+    qemu_printf("\t%s\n", enabled_isa);
+    qemu_printf("To get all configuable options for this cpu, use"
+                " -device %s,help\n", object_class_get_name(oc));
+}
+
 #define DEFINE_CPU(type_name, initfn)      \
     {                                      \
         .name = type_name,                 \
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 6ea22e0eea..af1d47605b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -443,9 +443,11 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                         bool probe, uintptr_t retaddr);
 char *riscv_isa_string(RISCVCPU *cpu);
 void riscv_cpu_list(void);
+void riscv_cpu_list_props(CPUState *cs);
 void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp);
 
 #define cpu_list riscv_cpu_list
+#define cpu_list_props riscv_cpu_list_props
 #define cpu_mmu_index riscv_cpu_mmu_index
 
 #ifndef CONFIG_USER_ONLY
-- 
2.17.1