diff --git a/tests/qemu-iotests/026.out b/tests/qemu-iotests/026.out
index dd10a82b51522b7f1d4503bfc6ec7859b6dbaf0a..fb89b8480c31e0ae00f91e14e1412d87f39a75fa 100644
--- a/tests/qemu-iotests/026.out
+++ b/tests/qemu-iotests/026.out
@@ -14,8 +14,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 1 leaked clusters were found on the image.
@@ -23,8 +23,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 1 leaked clusters were found on the image.
@@ -42,8 +42,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 1 leaked clusters were found on the image.
@@ -51,8 +51,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 1 leaked clusters were found on the image.
@@ -134,8 +134,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 127 leaked clusters were found on the image.
@@ -143,8 +143,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 127 leaked clusters were found on the image.
@@ -162,8 +162,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 127 leaked clusters were found on the image.
@@ -171,8 +171,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 127 leaked clusters were found on the image.
@@ -190,15 +190,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 1 leaked clusters were found on the image.
@@ -216,15 +216,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 1 leaked clusters were found on the image.
@@ -242,15 +242,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -266,15 +266,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -290,15 +290,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -314,15 +314,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -338,15 +338,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -362,15 +362,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -386,15 +386,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -410,15 +410,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -477,8 +477,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_hookup; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 55 leaked clusters were found on the image.
@@ -486,8 +486,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_hookup; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 251 leaked clusters were found on the image.
@@ -505,15 +505,15 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -529,8 +529,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 10 leaked clusters were found on the image.
@@ -538,8 +538,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 23 leaked clusters were found on the image.
@@ -557,8 +557,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 10 leaked clusters were found on the image.
@@ -566,8 +566,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 23 leaked clusters were found on the image.
@@ -585,8 +585,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_switch_table; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 10 leaked clusters were found on the image.
@@ -594,8 +594,8 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_switch_table; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 23 leaked clusters were found on the image.
@@ -631,8 +631,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -643,8 +643,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -655,8 +655,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_activate_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
+qemu-io: Failed to flush the L2 table cache: Input/output error
+qemu-io: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
 96 leaked clusters were found on the image.
@@ -669,8 +669,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_activate_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
+qemu-io: Failed to flush the L2 table cache: No space left on device
+qemu-io: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
 96 leaked clusters were found on the image.
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index af623cfd860f4f3064395bb2782502ff8bfadcee..ad1c18e9033ed65894d3f2d9fe1119e8d0aebdf9 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -20,7 +20,7 @@ Format specific information:
     lazy refcounts: false
     refcount bits: 16
     corrupt: true
-can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
+qemu-io: can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
 no file open, try 'help open'
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
@@ -267,7 +267,7 @@ No errors were found on the image.
 === Testing zero refcount table size ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.IMGFMT: Image does not contain a reference count table
+qemu-io: can't open device TEST_DIR/t.IMGFMT: Image does not contain a reference count table
 ERROR cluster 0 refcount=0 reference=1
 ERROR cluster 3 refcount=0 reference=1
 Rebuilding refcount structure
@@ -296,7 +296,7 @@ Can't get refcount for cluster 2: Input/output error
 Can't get refcount for cluster 3: Input/output error
 Rebuilding refcount structure
 Repairing cluster 1 refcount=1 reference=0
-can't open device TEST_DIR/t.IMGFMT: Could not repair dirty image: Input/output error
+qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not repair dirty image: Input/output error
 --- Repairing ---
 Leaked cluster 1 refcount=1 reference=0
 Repairing cluster 1 refcount=1 reference=0
diff --git a/tests/qemu-iotests/069.out b/tests/qemu-iotests/069.out
index f97585677b573ea065e5fcd7f04301a16f38a3e9..c78e8c2b720419d184f452c7f0d8f39f59adddc7 100644
--- a/tests/qemu-iotests/069.out
+++ b/tests/qemu-iotests/069.out
@@ -4,5 +4,5 @@ QA output created by 069
 
 Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=131072
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=131072 backing_file=TEST_DIR/t.IMGFMT.base
-can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
+qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
 *** done
diff --git a/tests/qemu-iotests/070.out b/tests/qemu-iotests/070.out
index c269d994834477eed9ed7f48d113bce03dfab6da..c7c567344cb81062ce2d5cf7a5d7be186f7a3c50 100644
--- a/tests/qemu-iotests/070.out
+++ b/tests/qemu-iotests/070.out
@@ -1,7 +1,7 @@
 QA output created by 070
 
 === Verify open image read-only fails, due to dirty log ===
-can't open device TEST_DIR/iotest-dirtylog-10G-4M.vhdx: VHDX image file 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx' opened read-only, but contains a log that needs to be replayed
+qemu-io: can't open device TEST_DIR/iotest-dirtylog-10G-4M.vhdx: VHDX image file 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx' opened read-only, but contains a log that needs to be replayed
 To replay the log, run:
 qemu-img check -r all 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx'
 === Verify open image replays log  ===
diff --git a/tests/qemu-iotests/075.out b/tests/qemu-iotests/075.out
index b234b758e0261757d49906f013a94d2c22c5ddf8..4f3871d33717dac8ce6afa7e01407090048fe234 100644
--- a/tests/qemu-iotests/075.out
+++ b/tests/qemu-iotests/075.out
@@ -9,23 +9,23 @@ read 512/512 bytes at offset 1048064
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == block_size must be a multiple of 512 ==
-can't open device TEST_DIR/simple-pattern.cloop: block_size 513 must be a multiple of 512
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size 513 must be a multiple of 512
 
 == block_size cannot be zero ==
-can't open device TEST_DIR/simple-pattern.cloop: block_size cannot be zero
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size cannot be zero
 
 == huge block_size ===
-can't open device TEST_DIR/simple-pattern.cloop: block_size 4294966784 must be 64 MB or less
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size 4294966784 must be 64 MB or less
 
 == offsets_size overflow ===
-can't open device TEST_DIR/simple-pattern.cloop: n_blocks 4294967295 must be 536870911 or less
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: n_blocks 4294967295 must be 536870911 or less
 
 == refuse images that require too many offsets ===
-can't open device TEST_DIR/simple-pattern.cloop: image requires too many offsets, try increasing block size
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: image requires too many offsets, try increasing block size
 
 == refuse images with non-monotonically increasing offsets ==
-can't open device TEST_DIR/simple-pattern.cloop: offsets not monotonically increasing at index 1, image file is corrupt
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: offsets not monotonically increasing at index 1, image file is corrupt
 
 == refuse images with invalid compressed block size ==
-can't open device TEST_DIR/simple-pattern.cloop: invalid compressed block size at index 1, image file is corrupt
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: invalid compressed block size at index 1, image file is corrupt
 *** done
diff --git a/tests/qemu-iotests/076.out b/tests/qemu-iotests/076.out
index 9c66c5fb46b72885896f1c1f8e6dd2b19ba255bf..2de8a710a55d659e1efdf394d3b6b766011570e4 100644
--- a/tests/qemu-iotests/076.out
+++ b/tests/qemu-iotests/076.out
@@ -5,13 +5,13 @@ read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Negative catalog size ==
-can't open device TEST_DIR/parallels-v1: Catalog too large
+qemu-io: can't open device TEST_DIR/parallels-v1: Catalog too large
 
 == Overflow in catalog allocation ==
-can't open device TEST_DIR/parallels-v1: Catalog too large
+qemu-io: can't open device TEST_DIR/parallels-v1: Catalog too large
 
 == Zero sectors per track ==
-can't open device TEST_DIR/parallels-v1: Invalid image: Zero sectors per track
+qemu-io: can't open device TEST_DIR/parallels-v1: Invalid image: Zero sectors per track
 
 == Read from a valid v2 image ==
 read 65536/65536 bytes at offset 0
diff --git a/tests/qemu-iotests/078.out b/tests/qemu-iotests/078.out
index c3d6aa4fe465bb240c1b75bb423d6db974f14892..4a82e1779fe37d13e8c5d308cc47ffb11e837a88 100644
--- a/tests/qemu-iotests/078.out
+++ b/tests/qemu-iotests/078.out
@@ -5,18 +5,18 @@ read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Negative catalog size ==
-can't open device TEST_DIR/empty.bochs: Catalog size is too large
+qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large
 
 == Overflow for catalog size * sizeof(uint32_t) ==
-can't open device TEST_DIR/empty.bochs: Catalog size is too large
+qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large
 
 == Too small catalog bitmap for image size ==
-can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
-can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
+qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
+qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
 
 == Negative extent size ==
-can't open device TEST_DIR/empty.bochs: Extent size 2147483648 is too large
+qemu-io: can't open device TEST_DIR/empty.bochs: Extent size 2147483648 is too large
 
 == Zero extent size ==
-can't open device TEST_DIR/empty.bochs: Extent size must be at least 512
+qemu-io: can't open device TEST_DIR/empty.bochs: Extent size must be at least 512
 *** done
diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
index 281c7e0d1d5a81a72a76780671ce1f756e999c57..45ab01db8ed80e9695a16f7e83cf667018cb7374 100644
--- a/tests/qemu-iotests/080.out
+++ b/tests/qemu-iotests/080.out
@@ -2,34 +2,34 @@ QA output created by 080
 
 == Huge header size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
-can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
 
 == Huge unknown header extension ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Invalid backing file offset
-can't open device TEST_DIR/t.qcow2: Header extension too large
-can't open device TEST_DIR/t.qcow2: Header extension too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset
+qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
 
 == Huge refcount table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Reference count table too large
-can't open device TEST_DIR/t.qcow2: Reference count table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
 
 == Misaligned refcount table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
 
 == Huge refcount offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
 
 == Invalid snapshot table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Snapshot table too large
-can't open device TEST_DIR/t.qcow2: Snapshot table too large
-can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
-can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
 
 == Hitting snapshot table size limit ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
@@ -39,10 +39,10 @@ read 512/512 bytes at offset 0
 
 == Invalid L1 table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Active L1 table too large
-can't open device TEST_DIR/t.qcow2: Active L1 table too large
-can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
-can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
 
 == Invalid L1 table (with internal snapshot in the image) ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
@@ -50,7 +50,7 @@ qemu-img: Could not open 'TEST_DIR/t.IMGFMT': L1 table is too small
 
 == Invalid backing file size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: Backing file name too long
+qemu-io: can't open device TEST_DIR/t.qcow2: Backing file name too long
 
 == Invalid L2 entry (huge physical offset) ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
@@ -66,7 +66,7 @@ wrote 512/512 bytes at offset 0
 qemu-img: Failed to load snapshot: Snapshot L1 table offset invalid
 qemu-img: Snapshot L1 table offset invalid
 qemu-img: Failed to turn zero into data clusters: Invalid argument
-Failed to flush the refcount block cache: Invalid argument
+qemu-io: Failed to flush the refcount block cache: Invalid argument
 write failed: Invalid argument
 qemu-img: Snapshot L1 table offset invalid
 qemu-img: Could not apply snapshot 'test': Failed to load snapshot: Invalid argument
@@ -89,7 +89,7 @@ wrote 512/512 bytes at offset 0
 qemu-img: Failed to load snapshot: Snapshot L1 table too large
 qemu-img: Snapshot L1 table too large
 qemu-img: Failed to turn zero into data clusters: File too large
-Failed to flush the refcount block cache: File too large
+qemu-io: Failed to flush the refcount block cache: File too large
 write failed: File too large
 qemu-img: Snapshot L1 table too large
 qemu-img: Could not apply snapshot 'test': Failed to load snapshot: File too large
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 8ec1783ffe77b54f5f55020f523bf9c6bffe6d14..04091b64e5dd277665d88a68aa90b4f579f88cd8 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -70,7 +70,7 @@ read 10485760/10485760 bytes at offset 0
 10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == checking the blkverify mode with invalid settings ==
-can't open: blkverify=on can only be set if there are exactly two files and vote-threshold is 2
+qemu-io: can't open: blkverify=on can only be set if there are exactly two files and vote-threshold is 2
 
 == dynamically adding a child to a quorum ==
 Testing:
diff --git a/tests/qemu-iotests/088.out b/tests/qemu-iotests/088.out
index 1f6bcf0abc97b2adbf0c20379c458dfc804dc92e..814be7181dc554a69ffa554f180b0fd390493828 100644
--- a/tests/qemu-iotests/088.out
+++ b/tests/qemu-iotests/088.out
@@ -2,10 +2,10 @@ QA output created by 088
 
 == Invalid block size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.vpc: Invalid block size 0
-can't open device TEST_DIR/t.vpc: Invalid block size 0
-can't open device TEST_DIR/t.vpc: Invalid block size 128
-can't open device TEST_DIR/t.vpc: Invalid block size 128
-can't open device TEST_DIR/t.vpc: Invalid block size 305419896
-can't open device TEST_DIR/t.vpc: Invalid block size 305419896
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 0
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 0
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 128
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 128
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 305419896
+qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 305419896
 *** done
diff --git a/tests/qemu-iotests/103.out b/tests/qemu-iotests/103.out
index bd9eec325028c534be7b3be685d4ffc1042a8816..16704cf499a006ca918fd797ea6de6ae4fee6b6e 100644
--- a/tests/qemu-iotests/103.out
+++ b/tests/qemu-iotests/103.out
@@ -5,13 +5,13 @@ wrote 65536/65536 bytes at offset 0
 
 === Testing invalid option combinations ===
 
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
-can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
+qemu-io: can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
+qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 
 === Testing valid option combinations ===
 
diff --git a/tests/qemu-iotests/114.out b/tests/qemu-iotests/114.out
index 1a47a526b92fef0c5fc3166d58ad8b340bfb4a35..22dc66c6335298dcc14d125efa74181aac05cb41 100644
--- a/tests/qemu-iotests/114.out
+++ b/tests/qemu-iotests/114.out
@@ -7,7 +7,7 @@ virtual size: 64M (67108864 bytes)
 cluster_size: 65536
 backing file: TEST_DIR/t.IMGFMT.base
 backing file format: foo
-can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
+qemu-io: can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
 no file open, try 'help open'
 read 4096/4096 bytes at offset 0
 4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
diff --git a/tests/qemu-iotests/116.out b/tests/qemu-iotests/116.out
index 24bee57783c6c55ed36f8241ca6acdf62e11b03a..49f9a261a012da1a59b4669acf0bb250c0e5b596 100644
--- a/tests/qemu-iotests/116.out
+++ b/tests/qemu-iotests/116.out
@@ -2,29 +2,29 @@ QA output created by 116
 
 == truncated header cluster ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 
 == invalid header magic ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Image not in QED format
+qemu-io: can't open device TEST_DIR/t.qed: Image not in QED format
 
 == invalid cluster size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 
 == invalid table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 
 == invalid header size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 
 == invalid L1 table offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 
 == invalid image size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 *** done
diff --git a/tests/qemu-iotests/131.out b/tests/qemu-iotests/131.out
index 27c2c5389b62f325bd7457b9b42ec95dc35c6c03..70da03dee5225b984abcb8d548333e74d6d5c552 100644
--- a/tests/qemu-iotests/131.out
+++ b/tests/qemu-iotests/131.out
@@ -22,7 +22,7 @@ read 32768/32768 bytes at offset 163840
 read 32768/32768 bytes at offset 0
 32 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 == Corrupt image ==
-can't open device TEST_DIR/t.parallels: parallels: Image was not closed correctly; cannot be opened read/write
+qemu-io: can't open device TEST_DIR/t.parallels: parallels: Image was not closed correctly; cannot be opened read/write
 ERROR image was not closed correctly
 
 1 errors were found on the image.
diff --git a/tests/qemu-iotests/133.out b/tests/qemu-iotests/133.out
index 414c7fa27fb2d9ff361e513400d22fe81cb88423..1491ef45a984dfc6a2e216011876467d4424a4b8 100644
--- a/tests/qemu-iotests/133.out
+++ b/tests/qemu-iotests/133.out
@@ -4,18 +4,18 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t
 
 === Check that node-name can't be changed ===
 
-Cannot change the option 'node-name'
-Cannot change the option 'node-name'
-Cannot change the option 'node-name'
+qemu-io: Cannot change the option 'node-name'
+qemu-io: Cannot change the option 'node-name'
+qemu-io: Cannot change the option 'node-name'
 
 === Check that unchanged node-name is okay ===
 
 
 === Check that driver can't be changed ===
 
-Cannot change the option 'driver'
-Cannot change the option 'driver'
-Cannot change the option 'driver'
+qemu-io: Cannot change the option 'driver'
+qemu-io: Cannot change the option 'driver'
+qemu-io: Cannot change the option 'driver'
 
 === Check that unchanged driver is okay ===
 
@@ -27,16 +27,16 @@ format name: null-co
 
 === Check that mixing -c/-r/-w and their corresponding options is forbidden ===
 
-Cannot set both -r/-w and 'read-only'
-Cannot set both -r/-w and 'read-only'
-Cannot set both -c and the cache options
-Cannot set both -c and the cache options
-Cannot set both -c and the cache options
+qemu-io: Cannot set both -r/-w and 'read-only'
+qemu-io: Cannot set both -r/-w and 'read-only'
+qemu-io: Cannot set both -c and the cache options
+qemu-io: Cannot set both -c and the cache options
+qemu-io: Cannot set both -c and the cache options
 
 === Check that invalid options are handled correctly ===
 
-Parameter 'read-only' expects 'on' or 'off'
-Parameter 'cache.no-flush' expects 'on' or 'off'
-Parameter 'cache.direct' expects 'on' or 'off'
-Parameter 'auto-read-only' expects 'on' or 'off'
+qemu-io: Parameter 'read-only' expects 'on' or 'off'
+qemu-io: Parameter 'cache.no-flush' expects 'on' or 'off'
+qemu-io: Parameter 'cache.direct' expects 'on' or 'off'
+qemu-io: Parameter 'auto-read-only' expects 'on' or 'off'
 *** done
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index 2c080b72f3db8f9acd763bf3daacffcddd2b8eb6..22d59df40c4e0dcdf9170afebeb15258b87233c1 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -15,24 +15,24 @@ read 33554432/33554432 bytes at offset 0
 
 === Try setting some invalid values ===
 
-Parameter 'lazy-refcounts' expects 'on' or 'off'
-cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-l2-cache-size may not exceed cache-size
-refcount-cache-size may not exceed cache-size
-L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-Refcount cache size too big
-Conflicting values for qcow2 options 'overlap-check' ('constant') and 'overlap-check.template' ('all')
-Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
-Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
-Cache clean interval too big
+qemu-io: Parameter 'lazy-refcounts' expects 'on' or 'off'
+qemu-io: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: l2-cache-size may not exceed cache-size
+qemu-io: refcount-cache-size may not exceed cache-size
+qemu-io: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: Refcount cache size too big
+qemu-io: Conflicting values for qcow2 options 'overlap-check' ('constant') and 'overlap-check.template' ('all')
+qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: Cache clean interval too big
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=36028797018963968
-L2 cache size too big
+qemu-io: L2 cache size too big
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 
 === Test transaction semantics ===
 
-Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 ./common.rc: Killed                  ( if [ "${VALGRIND_QEMU}" == "y" ]; then
@@ -44,7 +44,7 @@ incompatible_features     0x0
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Parameter 'lazy-refcounts' expects 'on' or 'off'
+qemu-io: Parameter 'lazy-refcounts' expects 'on' or 'off'
 qcow2: Marking image as corrupt: Preventing invalid write on metadata (overlaps with qcow2_header); further corruption events will be suppressed
 write failed: Input/output error
 *** done
diff --git a/tests/qemu-iotests/140.out b/tests/qemu-iotests/140.out
index 704adcef40f03ad308b8c4460a1b561b2c2b7260..67fe44a3e390c5e40a58a64b7bfb551ff97bd1ef 100644
--- a/tests/qemu-iotests/140.out
+++ b/tests/qemu-iotests/140.out
@@ -8,7 +8,7 @@ wrote 65536/65536 bytes at offset 0
 read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": {}}
-can't open device nbd+unix:///drv?socket=TEST_DIR/nbd: Requested export not available
+qemu-io: can't open device nbd+unix:///drv?socket=TEST_DIR/nbd: Requested export not available
 server reported: export 'drv' not present
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
diff --git a/tests/qemu-iotests/143.out b/tests/qemu-iotests/143.out
index 3e55fcd0acd6df6b2c1d2ab95633337d37087416..ee71b5aa42f0557c593de2e4dde9cdaf674e2949 100644
--- a/tests/qemu-iotests/143.out
+++ b/tests/qemu-iotests/143.out
@@ -1,7 +1,7 @@
 QA output created by 143
 {"return": {}}
 {"return": {}}
-can't open device nbd+unix:///no_such_export?socket=TEST_DIR/nbd: Requested export not available
+qemu-io: can't open device nbd+unix:///no_such_export?socket=TEST_DIR/nbd: Requested export not available
 server reported: export 'no_such_export' not present
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index 9747ce3c41961215d68a29657934b8ddd02a44cc..021c1cb899652044f29c450ddb56bf4b23a82edf 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -23,20 +23,20 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r  TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
@@ -100,12 +100,12 @@ file format: IMGFMT
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -166,13 +166,13 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
@@ -222,12 +222,12 @@ file format: IMGFMT
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -325,12 +325,12 @@ file format: IMGFMT
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -420,7 +420,7 @@ Adding drive
 {"return": "OKrn"}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 Creating overlay with qemu-img when the guest is running should be allowed
 
@@ -437,7 +437,7 @@ _qemu_img_wrapper info TEST_DIR/t.qcow2
 {"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 Closing the other
 {"return": ""}
@@ -458,5 +458,5 @@ qemu-img: --force-share/-U conflicts with image options
 No conflict:
 
 Conflict:
--U conflicts with image options
+qemu-io: -U conflicts with image options
 *** done
diff --git a/tests/qemu-iotests/187.out b/tests/qemu-iotests/187.out
index 30b987f71f8df7ac02bd398bd8707a86eca67eec..86203d8abcb022afccc2f631be71131530b54d70 100644
--- a/tests/qemu-iotests/187.out
+++ b/tests/qemu-iotests/187.out
@@ -3,16 +3,16 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 
 Start from read-only
 
-Block node is read-only
+qemu-io: Block node is read-only
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Block node is read-only
+qemu-io: Block node is read-only
 
 Start from read-write
 
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Block node is read-only
+qemu-io: Block node is read-only
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 *** done
diff --git a/tests/qemu-iotests/188.out b/tests/qemu-iotests/188.out
index 8af24e5d8b7ed975414d38615fde502e4c2cff1b..97b1402671bf8a6d0651619ebefd82be137b88df 100644
--- a/tests/qemu-iotests/188.out
+++ b/tests/qemu-iotests/188.out
@@ -14,5 +14,5 @@ read 16777216/16777216 bytes at offset 0
 16 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == verify open failure with wrong password ==
-can't open: Invalid password, cannot unlock any keyslot
+qemu-io: can't open: Invalid password, cannot unlock any keyslot
 *** done
diff --git a/tests/qemu-iotests/197.out b/tests/qemu-iotests/197.out
index 8febda5dea9fc68b9f337c618792e2768530042c..7ca46be6e488693c055a3b5e5b529c14fac17309 100644
--- a/tests/qemu-iotests/197.out
+++ b/tests/qemu-iotests/197.out
@@ -16,7 +16,7 @@ read 2147483136/2147483136 bytes at offset 1024
 2 GiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 1024/1024 bytes at offset 3221226496
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-can't open device TEST_DIR/t.wrap.qcow2: Can't use copy-on-read on read-only device
+qemu-io: can't open device TEST_DIR/t.wrap.qcow2: Can't use copy-on-read on read-only device
 2 GiB (0x80010000) bytes     allocated at offset 0 bytes (0x0)
 1023.938 MiB (0x3fff0000) bytes not allocated at offset 2 GiB (0x80010000)
 64 KiB (0x10000) bytes     allocated at offset 3 GiB (0xc0000000)
diff --git a/tests/qemu-iotests/205 b/tests/qemu-iotests/205
index 31b2f5707a5da897e3c75c55a2307e724e1d45b9..69f2c1d392de3cd0a866e0899b05fddb96bcac14 100755
--- a/tests/qemu-iotests/205
+++ b/tests/qemu-iotests/205
@@ -78,7 +78,7 @@ class TestNbdServerRemove(iotests.QMPTestCase):
 
     def assertConnectFailed(self, qemu_io_output):
         self.assertEqual(filter_qemu_io(qemu_io_output).strip(),
-                         "can't open device " + nbd_uri +
+                         "qemu-io: can't open device " + nbd_uri +
                          ": Requested export not available\n"
                          "server reported: export 'exp' not present")
 
diff --git a/tests/qemu-iotests/215.out b/tests/qemu-iotests/215.out
index 70b0f5fb1956382be935004982ae602c9f457b17..5a2fe40d0314ae7f872d9a2690a5f61c69e66e76 100644
--- a/tests/qemu-iotests/215.out
+++ b/tests/qemu-iotests/215.out
@@ -16,7 +16,7 @@ read 2147483136/2147483136 bytes at offset 1024
 2 GiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 1024/1024 bytes at offset 3221226496
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-can't open device TEST_DIR/t.wrap.qcow2: Block node is read-only
+qemu-io: can't open device TEST_DIR/t.wrap.qcow2: Block node is read-only
 2 GiB (0x80010000) bytes     allocated at offset 0 bytes (0x0)
 1023.938 MiB (0x3fff0000) bytes not allocated at offset 2 GiB (0x80010000)
 64 KiB (0x10000) bytes     allocated at offset 3 GiB (0xc0000000)
diff --git a/tests/qemu-iotests/226.out b/tests/qemu-iotests/226.out
index 8c0d060ffc582103cab5147d8cd08f2d4771ff66..42be973ff20fd297bc7d3f19b26b9cd3dffd1697 100644
--- a/tests/qemu-iotests/226.out
+++ b/tests/qemu-iotests/226.out
@@ -3,24 +3,24 @@ QA output created by 226
 === Testing with driver:file ===
 
 == Testing RO ==
-can't open: A regular file was expected by the 'file' driver, but something else was given
-warning: Opening a character device as a file using the 'file' driver is deprecated
+qemu-io: can't open: A regular file was expected by the 'file' driver, but something else was given
+qemu-io: warning: Opening a character device as a file using the 'file' driver is deprecated
 == Testing RW ==
-can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
-warning: Opening a character device as a file using the 'file' driver is deprecated
+qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: warning: Opening a character device as a file using the 'file' driver is deprecated
 
 === Testing with driver:host_device ===
 
 == Testing RO ==
-can't open: 'host_device' driver expects either a character or block device
+qemu-io: can't open: 'host_device' driver expects either a character or block device
 == Testing RW ==
-can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
 
 === Testing with driver:host_cdrom ===
 
 == Testing RO ==
-can't open: 'host_cdrom' driver expects either a character or block device
+qemu-io: can't open: 'host_cdrom' driver expects either a character or block device
 == Testing RW ==
-can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
 
 *** done
diff --git a/tests/qemu-iotests/244.out b/tests/qemu-iotests/244.out
index 98e5946976da8f9cef3e74292695958f8bb6d18d..6a3d0067ccc04e22e72da029d2f26da484f8ad5d 100644
--- a/tests/qemu-iotests/244.out
+++ b/tests/qemu-iotests/244.out
@@ -9,22 +9,22 @@ read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 Data file required, but without data file name in the image:
-can't open device TEST_DIR/t.qcow2: 'data-file' is required for this image
+qemu-io: can't open device TEST_DIR/t.qcow2: 'data-file' is required for this image
 no file open, try 'help open'
 read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 Setting data-file for an image with internal data:
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-can't open device TEST_DIR/t.qcow2: 'data-file' can only be set for images with an external data file
+qemu-io: can't open device TEST_DIR/t.qcow2: 'data-file' can only be set for images with an external data file
 no file open, try 'help open'
-can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 === Conflicting features ===