diff --git a/README.md b/README.md
index 07def0623..1869dbb0a 100644
--- a/README.md
+++ b/README.md
@@ -163,6 +163,7 @@ hugetlbfs       /mnt/huge  hugetlbfs       rw,mode=0777        0 0
 
 # Compille Time Option
 -DTAP_IGNORE_ERROR: when packetgrapg can't burst or poll a tap, it return 0 instead of returning an error
+-DPG_QEMU_MEM_SIZE=SIZE: allow to specify qemy ram size in test, parameter must be a string in qemu format, examples: -DPG_QEMU_MEM_SIZE="1G", -DPG_QEMU_MEM_SIZE="512M"
 
 # Licence
 
diff --git a/src/utils/common.h b/src/utils/common.h
index 9d022a724..9ed4e2ef1 100644
--- a/src/utils/common.h
+++ b/src/utils/common.h
@@ -48,7 +48,10 @@ static inline void pg_brick_ptrptr_destroy(struct pg_brick **brick)
 #define PG_STRCAT7(a, b, c, d, e, f, g) (a b c d e f g)
 #define PG_STRCAT8(a, b, c, d, e, f, g, h) (a b c d e f g h)
 #define PG_STRCAT9(a, b, c, d, e, f, g, h, i) (a b c d e f g h i)
-#define PG_STRCAT10(a, b, c, d, e, f, g, h, i, j) (a b c d e f g h i j)
+#define PG_STRCAT10(a, b, c, d, e, f, g, h, i, j)	\
+	(a b c d e f g h i j)
+#define PG_STRCAT11(a, b, c, d, e, f, g, h, i, j, k)	\
+	(a b c d e f g h i j k)
 
 #define PG_CAT(a, b) a ## b
 
diff --git a/src/utils/qemu.c b/src/utils/qemu.c
index 10b451009..bb2033213 100644
--- a/src/utils/qemu.c
+++ b/src/utils/qemu.c
@@ -24,6 +24,10 @@
 #include "utils/qemu.h"
 #include "utils/common.h"
 
+#ifndef PG_QEMU_MEM_SIZE
+#define PG_QEMU_MEM_SIZE "128G"
+#endif
+
 int pg_util_cmdloop(const char *cmd, int timeout_s)
 {
 	struct timeval start, end;
@@ -111,10 +115,13 @@ int pg_util_spawn_qemu(const char *socket_path_0,
 
 	argv_qemu = g_strdup_printf(
 		PG_STRCAT(
-			"qemu-system-x86_64 -m 1G -enable-kvm",
+			"qemu-system-x86_64 -m ",
+			PG_QEMU_MEM_SIZE,
+			" -enable-kvm",
 			" -vnc :%u -display none -snapshot -object",
-			" memory-backend-file,id=mem,size=1G,",
-			"mem-path=%s,share=on -numa node,memdev=mem",
+			" memory-backend-file,id=mem,size=",
+			PG_QEMU_MEM_SIZE,
+			",mem-path=%s,share=on -numa node,memdev=mem",
 			" -mem-prealloc -drive file=%s",
 			" -netdev user,id=net0,hostfwd=tcp::%u-:22",
 			" -device e1000,netdev=net0%s%s",