diff --git a/emu.c b/emu.c
index 6c26796..8bed5b0 100644
--- a/emu.c
+++ b/emu.c
@@ -1068,6 +1068,7 @@ init_cpus(struct ovni_emu *emu)
 				err("error cpu %ld.%ld name too long\n", i, j);
 				exit(EXIT_FAILURE);
 			}
+			cpu->virtual = 0;
 		}
 
 		emu->global_cpu[loom->vcpu.gindex] = &loom->vcpu;
@@ -1077,6 +1078,7 @@ init_cpus(struct ovni_emu *emu)
 			err("error cpu %ld.* name too long\n", i);
 			exit(EXIT_FAILURE);
 		}
+		loom->vcpu.virtual = 1;
 	}
 }
 
diff --git a/emu.h b/emu.h
index 16aaaa3..17c0c96 100644
--- a/emu.h
+++ b/emu.h
@@ -368,6 +368,9 @@ struct ovni_cpu {
 
 	/* Cpu name as shown in paraver row */
 	char name[MAX_CPU_NAME];
+
+	/* Is this a virtual CPU? */
+	int virtual;
 };
 
 /* ----------------------- trace ------------------------ */