diff --git a/bsd-user/main.c b/bsd-user/main.c
index 76ab35909c26e2f527ae8a0fbeb9038ec21a72d2..26604b43cbcf39f37b74d49f138a08b322c3e871 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -864,14 +864,10 @@ int main(int argc, char **argv)
     qemu_set_log_filename(log_file);
     if (log_mask) {
         int mask;
-        const CPULogItem *item;
 
         mask = cpu_str_to_log_mask(log_mask);
         if (!mask) {
-            printf("Log items (comma separated):\n");
-            for (item = cpu_log_items; item->mask != 0; item++) {
-                printf("%-10s %s\n", item->name, item->help);
-            }
+            qemu_print_log_usage(stdout);
             exit(1);
         }
         cpu_set_log(mask);
diff --git a/cpus.c b/cpus.c
index 2155441b35c8c30e84f95e00679ecfd80435131a..0fdc48ca883b743d85e3935e183d63f624fcd9c9 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1178,14 +1178,10 @@ void set_numa_modes(void)
 void set_cpu_log(const char *optarg)
 {
     int mask;
-    const CPULogItem *item;
 
     mask = cpu_str_to_log_mask(optarg);
     if (!mask) {
-        printf("Log items (comma separated):\n");
-        for (item = cpu_log_items; item->mask != 0; item++) {
-            printf("%-10s %s\n", item->name, item->help);
-        }
+        qemu_print_log_usage(stdout);
         exit(1);
     }
     cpu_set_log(mask);
diff --git a/include/qemu/log.h b/include/qemu/log.h
index 4760e04c5e0b342ab68fc9f6d70c664a4c5c041e..59511a3748c327c06a820e4a6dff4ad01cb3dfb4 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -157,4 +157,9 @@ static inline void cpu_set_log(int log_flags)
 void qemu_set_log_filename(const char *filename);
 int cpu_str_to_log_mask(const char *str);
 
+/* Print a usage message listing all the valid logging categories
+ * to the specified FILE*.
+ */
+void qemu_print_log_usage(FILE *f);
+
 #endif
diff --git a/linux-user/main.c b/linux-user/main.c
index 4beb5c9ae53fa2f2e2bcd4c5a43afa1ba0fc633b..00b01254143ea651114ed8c77a7b38efbd24dca9 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3098,14 +3098,10 @@ static void handle_arg_help(const char *arg)
 static void handle_arg_log(const char *arg)
 {
     int mask;
-    const CPULogItem *item;
 
     mask = cpu_str_to_log_mask(arg);
     if (!mask) {
-        printf("Log items (comma separated):\n");
-        for (item = cpu_log_items; item->mask != 0; item++) {
-            printf("%-10s %s\n", item->name, item->help);
-        }
+        qemu_print_log_usage(stdout);
         exit(1);
     }
     cpu_set_log(mask);
diff --git a/qemu-log.c b/qemu-log.c
index 9a7e5675a14b843b9f0fe4844cced09c3aa65cb0..786d3358931a3fae34b35e81e469cc986670c51c 100644
--- a/qemu-log.c
+++ b/qemu-log.c
@@ -170,3 +170,12 @@ int cpu_str_to_log_mask(const char *str)
     }
     return mask;
 }
+
+void qemu_print_log_usage(FILE *f)
+{
+    const CPULogItem *item;
+    fprintf(f, "Log items (comma separated):\n");
+    for (item = cpu_log_items; item->mask != 0; item++) {
+        fprintf(f, "%-10s %s\n", item->name, item->help);
+    }
+}