diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 0217006c27..589ae72a59 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -811,7 +811,6 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
     MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
     char *plic_hart_config;
-    size_t plic_hart_config_len;
     int i, j;
     NICInfo *nd = &nd_table[0];
 
@@ -852,18 +851,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
                                 l2lim_mem);
 
     /* create PLIC hart topology configuration string */
-    plic_hart_config_len = (strlen(SIFIVE_U_PLIC_HART_CONFIG) + 1) *
-                           ms->smp.cpus;
-    plic_hart_config = g_malloc0(plic_hart_config_len);
-    for (i = 0; i < ms->smp.cpus; i++) {
-        if (i != 0) {
-            strncat(plic_hart_config, "," SIFIVE_U_PLIC_HART_CONFIG,
-                    plic_hart_config_len);
-        } else {
-            strncat(plic_hart_config, "M", plic_hart_config_len);
-        }
-        plic_hart_config_len -= (strlen(SIFIVE_U_PLIC_HART_CONFIG) + 1);
-    }
+    plic_hart_config = riscv_plic_hart_config_string(ms->smp.cpus);
 
     /* MMIO */
     s->plic = sifive_plic_create(memmap[SIFIVE_U_DEV_PLIC].base,
diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
index f71c90c94c..8f63a183c4 100644
--- a/include/hw/riscv/sifive_u.h
+++ b/include/hw/riscv/sifive_u.h
@@ -156,7 +156,6 @@ enum {
 #define SIFIVE_U_MANAGEMENT_CPU_COUNT   1
 #define SIFIVE_U_COMPUTE_CPU_COUNT      4
 
-#define SIFIVE_U_PLIC_HART_CONFIG "MS"
 #define SIFIVE_U_PLIC_NUM_SOURCES 54
 #define SIFIVE_U_PLIC_NUM_PRIORITIES 7
 #define SIFIVE_U_PLIC_PRIORITY_BASE 0x04