diff --git a/qtest.c b/qtest.c
index 73b7a0f9b8..04412ddde1 100644
--- a/qtest.c
+++ b/qtest.c
@@ -125,6 +125,9 @@ static bool qtest_opened;
  *  > b64write ADDR SIZE B64_DATA
  *  < OK
  *
+ *  > memset ADDR SIZE VALUE
+ *  < OK
+ *
  * ADDR, SIZE, VALUE are all integers parsed with strtoul() with a base of 0.
  *
  * DATA is an arbitrarily long hex number prefixed with '0x'.  If it's smaller
@@ -471,6 +474,23 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         cpu_physical_memory_write(addr, data, len);
         g_free(data);
 
+        qtest_send_prefix(chr);
+        qtest_send(chr, "OK\n");
+    } else if (strcmp(words[0], "memset") == 0) {
+        uint64_t addr, len;
+        uint8_t *data;
+        uint8_t pattern;
+
+        g_assert(words[1] && words[2] && words[3]);
+        addr = strtoull(words[1], NULL, 0);
+        len = strtoull(words[2], NULL, 0);
+        pattern = strtoull(words[3], NULL, 0);
+
+        data = g_malloc(len);
+        memset(data, pattern, len);
+        cpu_physical_memory_write(addr, data, len);
+        g_free(data);
+
         qtest_send_prefix(chr);
         qtest_send(chr, "OK\n");
     }  else if (strcmp(words[0], "b64write") == 0) {
diff --git a/tests/libqtest.c b/tests/libqtest.c
index 5f57005447..055aad69e0 100644
--- a/tests/libqtest.c
+++ b/tests/libqtest.c
@@ -741,13 +741,7 @@ void qtest_memwrite(QTestState *s, uint64_t addr, const void *data, size_t size)
 
 void qtest_memset(QTestState *s, uint64_t addr, uint8_t pattern, size_t size)
 {
-    size_t i;
-
-    qtest_sendf(s, "write 0x%" PRIx64 " 0x%zx 0x", addr, size);
-    for (i = 0; i < size; i++) {
-        qtest_sendf(s, "%02x", pattern);
-    }
-    qtest_sendf(s, "\n");
+    qtest_sendf(s, "memset 0x%" PRIx64 " 0x%zx 0x%02x\n", addr, size, pattern);
     qtest_rsp(s, 0);
 }