[Qemu-devel] [PATCH for-2.8 v1 16/60] trace: introduce ID range offsets per trace-events file

[Daniel P. Berrange]

For simpletrace we need to be able to form a globally
unique ID value for trace records. Since the individual
events no longer have globally unique ID values, we
define an event ID offset per trace-events file.

The simpletrace records will now use

    (id_offset << 16) | event_id

for the ID value in trace records.

Signed-off-by: Daniel P. Berrange <address@hidden>
---
 audio/trace-events                           |  2 ++
 block/trace-events                           |  2 ++
 crypto/trace-events                          |  2 ++
 hw/9pfs/trace-events                         |  2 ++
 hw/acpi/trace-events                         |  2 ++
 hw/alpha/trace-events                        |  2 ++
 hw/arm/trace-events                          |  2 ++
 hw/audio/trace-events                        |  2 ++
 hw/block/trace-events                        |  2 ++
 hw/char/trace-events                         |  2 ++
 hw/display/trace-events                      |  2 ++
 hw/dma/trace-events                          |  2 ++
 hw/i386/trace-events                         |  2 ++
 hw/input/trace-events                        |  2 ++
 hw/intc/trace-events                         |  2 ++
 hw/isa/trace-events                          |  2 ++
 hw/mem/trace-events                          |  2 ++
 hw/misc/trace-events                         |  2 ++
 hw/net/trace-events                          |  2 ++
 hw/nvram/trace-events                        |  2 ++
 hw/pci/trace-events                          |  2 ++
 hw/ppc/trace-events                          |  2 ++
 hw/s390x/trace-events                        |  2 ++
 hw/scsi/trace-events                         |  2 ++
 hw/sd/trace-events                           |  2 ++
 hw/sparc/trace-events                        |  2 ++
 hw/timer/trace-events                        |  2 ++
 hw/usb/trace-events                          |  2 ++
 hw/vfio/trace-events                         |  2 ++
 hw/virtio/trace-events                       |  2 ++
 io/trace-events                              |  2 ++
 linux-user/trace-events                      |  2 ++
 migration/trace-events                       |  2 ++
 net/trace-events                             |  2 ++
 qom/trace-events                             |  2 ++
 scripts/simpletrace.py                       |  7 ++--
 scripts/tracetool/__init__.py                | 49 +++++++++++++++++++++++-----
 scripts/tracetool/backend/simple.py          |  3 +-
 scripts/tracetool/format/simpletrace_stap.py |  2 +-
 target-i386/trace-events                     |  2 ++
 target-ppc/trace-events                      |  2 ++
 target-s390x/trace-events                    |  2 ++
 target-sparc/trace-events                    |  2 ++
 trace-events                                 |  2 ++
 ui/trace-events                              |  2 ++
 util/trace-events                            |  2 ++
 46 files changed, 131 insertions(+), 14 deletions(-)

diff --git a/audio/trace-events b/audio/trace-events
index 5638ea1..5630465 100644
--- a/audio/trace-events
+++ b/audio/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(512)
+
 # audio/alsaaudio.c
 alsa_revents(int revents) "revents = %d"
 alsa_pollout(int i, int fd) "i = %d fd = %d"
diff --git a/block/trace-events b/block/trace-events
index 978ef4f..8286458 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(25)
+
 # block.c
 bdrv_open_common(void *bs, const char *filename, int flags, const char 
*format_name) "bs %p filename \"%s\" flags %#x format_name \"%s\""
 bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
diff --git a/crypto/trace-events b/crypto/trace-events
index 71f1d99..9850d0d 100644
--- a/crypto/trace-events
+++ b/crypto/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(32)
+
 # crypto/tlscreds.c
 qcrypto_tls_creds_load_dh(void *creds, const char *filename) "TLS creds load 
DH creds=%p filename=%s"
 qcrypto_tls_creds_get_path(void *creds, const char *filename, const char 
*path) "TLS creds path creds=%p filename=%s path=%s"
diff --git a/hw/9pfs/trace-events b/hw/9pfs/trace-events
index 63efa27..84275da 100644
--- a/hw/9pfs/trace-events
+++ b/hw/9pfs/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(196)
+
 # hw/9pfs/virtio-9p.c
 v9fs_rerror(uint16_t tag, uint8_t id, int err) "tag %d id %d err %d"
 v9fs_version(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d 
id %d msize %d version %s"
diff --git a/hw/acpi/trace-events b/hw/acpi/trace-events
index 5aa3ba6..840928e 100644
--- a/hw/acpi/trace-events
+++ b/hw/acpi/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(225)
+
 # hw/acpi/memory_hotplug.c
 mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32
 mhp_acpi_ejecting_invalid_slot(uint32_t slot) "0x%"PRIx32
diff --git a/hw/alpha/trace-events b/hw/alpha/trace-events
index 7d52b5d..7963ee4 100644
--- a/hw/alpha/trace-events
+++ b/hw/alpha/trace-events
@@ -1,4 +1,6 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(169)
+
 # hw/alpha/pci.c
 alpha_pci_iack_write(void) ""
diff --git a/hw/arm/trace-events b/hw/arm/trace-events
index d0dad16..e1f9d5c 100644
--- a/hw/arm/trace-events
+++ b/hw/arm/trace-events
@@ -1,4 +1,6 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(324)
+
 # hw/arm/virt-acpi-build.c
 virt_acpi_setup(void) "No fw cfg or ACPI disabled. Bailing out."
diff --git a/hw/audio/trace-events b/hw/audio/trace-events
index 796f4a1..0610b63 100644
--- a/hw/audio/trace-events
+++ b/hw/audio/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(243)
+
 # hw/audio/cs4231.c
 cs4231_mem_readl_dreg(uint32_t reg, uint32_t ret) "read dreg %d: 0x%02x"
 cs4231_mem_readl_reg(uint32_t reg, uint32_t ret) "read reg %d: 0x%08x"
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 31df44b..4c79bc0 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(49)
+
 # hw/block/virtio-blk.c
 virtio_blk_req_complete(void *req, int status) "req %p status %d"
 virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"
diff --git a/hw/char/trace-events b/hw/char/trace-events
index 005fcd8..fec6fc3 100644
--- a/hw/char/trace-events
+++ b/hw/char/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(288)
+
 # hw/char/virtio-serial-bus.c
 virtio_serial_send_control_event(unsigned int port, uint16_t event, uint16_t 
value) "port %u, event %u, value %u"
 virtio_serial_throttle_port(unsigned int port, bool throttle) "port %u, 
throttle %d"
diff --git a/hw/display/trace-events b/hw/display/trace-events
index 78f0465..4dd88aa 100644
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(100)
+
 # hw/display/jazz_led.c
 jazz_led_read(uint64_t addr, uint8_t val) "read addr=0x%"PRIx64": 0x%x"
 jazz_led_write(uint64_t addr, uint8_t new) "write addr=0x%"PRIx64": 0x%x"
diff --git a/hw/dma/trace-events b/hw/dma/trace-events
index d8a5674..685460d 100644
--- a/hw/dma/trace-events
+++ b/hw/dma/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(72)
+
 # hw/dma/rc4030.c
 jazzio_read(uint64_t addr, uint32_t ret) "read reg[0x%"PRIx64"] = 0x%x"
 jazzio_write(uint64_t addr, uint32_t val) "write reg[0x%"PRIx64"] = 0x%x"
diff --git a/hw/i386/trace-events b/hw/i386/trace-events
index 507f753..6ee0130 100644
--- a/hw/i386/trace-events
+++ b/hw/i386/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(392)
+
 # hw/i386/xen/xen_platform.c
 xen_platform_log(char *s) "xen platform: %s"
 
diff --git a/hw/input/trace-events b/hw/input/trace-events
index f24dff2..c78af6c 100644
--- a/hw/input/trace-events
+++ b/hw/input/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(432)
+
 # hw/input/ps2.c
 ps2_put_keycode(void *opaque, int keycode) "%p keycode %d"
 ps2_read_data(void *opaque) "%p"
diff --git a/hw/intc/trace-events b/hw/intc/trace-events
index 376dd18..ee46617 100644
--- a/hw/intc/trace-events
+++ b/hw/intc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(144)
+
 # hw/intc/apic_common.c
 cpu_set_apic_base(uint64_t val) "%016"PRIx64
 cpu_get_apic_base(uint64_t val) "%016"PRIx64
diff --git a/hw/isa/trace-events b/hw/isa/trace-events
index 686282f..b6b8ba6 100644
--- a/hw/isa/trace-events
+++ b/hw/isa/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(400)
+
 # hw/isa/pc87312.c
 pc87312_io_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
 pc87312_io_write(uint32_t addr, uint32_t val) "write addr=%x val=%x"
diff --git a/hw/mem/trace-events b/hw/mem/trace-events
index 3a49215..4b67bba 100644
--- a/hw/mem/trace-events
+++ b/hw/mem/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(36)
+
 # hw/mem/pc-dimm.c
 mhp_pc_dimm_assigned_slot(int slot) "0x%d"
 mhp_pc_dimm_assigned_address(uint64_t addr) "0x%"PRIx64
diff --git a/hw/misc/trace-events b/hw/misc/trace-events
index ea52a14..31db6a7 100644
--- a/hw/misc/trace-events
+++ b/hw/misc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(361)
+
 # hw/misc/eccmemctl.c
 ecc_mem_writel_mer(uint32_t val) "Write memory enable %08x"
 ecc_mem_writel_mdr(uint32_t val) "Write memory delay %08x"
diff --git a/hw/net/trace-events b/hw/net/trace-events
index aaa905f..a78e8c6 100644
--- a/hw/net/trace-events
+++ b/hw/net/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(289)
+
 # hw/net/lance.c
 lance_mem_readw(uint64_t addr, uint32_t ret) "addr=%"PRIx64"val=0x%04x"
 lance_mem_writew(uint64_t addr, uint32_t val) "addr=%"PRIx64"val=0x%04x"
diff --git a/hw/nvram/trace-events b/hw/nvram/trace-events
index 325447d..f026896 100644
--- a/hw/nvram/trace-events
+++ b/hw/nvram/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(256)
+
 # hw/nvram/ds1225y.c
 nvram_read(uint32_t addr, uint32_t ret) "read addr %d: 0x%02x"
 nvram_write(uint32_t addr, uint32_t old, uint32_t val) "write addr %d: 0x%02x 
-> 0x%02x"
diff --git a/hw/pci/trace-events b/hw/pci/trace-events
index 285338a..7803590 100644
--- a/hw/pci/trace-events
+++ b/hw/pci/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(121)
+
 # hw/pci/pci.c
 pci_update_mappings_del(void *d, uint32_t bus, uint32_t slot, uint32_t func, 
int bar, uint64_t addr, uint64_t size) "d=%p %02x:%02x.%x 
%d,%#"PRIx64"+%#"PRIx64
 pci_update_mappings_add(void *d, uint32_t bus, uint32_t slot, uint32_t func, 
int bar, uint64_t addr, uint64_t size) "d=%p %02x:%02x.%x 
%d,%#"PRIx64"+%#"PRIx64
diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events
index 900679b..d372099 100644
--- a/hw/ppc/trace-events
+++ b/hw/ppc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(125)
+
 # hw/ppc/spapr_pci.c
 spapr_pci_msi(const char *msg, uint32_t ca) "%s (cfg=%x)"
 spapr_pci_msi_setup(const char *name, unsigned vector, uint64_t addr) 
"dev\"%s\" vector %u, addr=%"PRIx64
diff --git a/hw/s390x/trace-events b/hw/s390x/trace-events
index 72c4549..59305ca 100644
--- a/hw/s390x/trace-events
+++ b/hw/s390x/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(64)
+
 # hw/s390x/css.c
 css_enable_facility(const char *facility) "CSS: enable %s"
 css_crw(uint8_t rsc, uint8_t erc, uint16_t rsid, const char *chained) "CSS: 
queueing crw: rsc=%x, erc=%x, rsid=%x %s"
diff --git a/hw/scsi/trace-events b/hw/scsi/trace-events
index 5f19e32..42e699e 100644
--- a/hw/scsi/trace-events
+++ b/hw/scsi/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(200)
+
 # hw/scsi/scsi-bus.c
 scsi_req_alloc(int target, int lun, int tag) "target %d lun %d tag %d"
 scsi_req_cancel(int target, int lun, int tag) "target %d lun %d tag %d"
diff --git a/hw/sd/trace-events b/hw/sd/trace-events
index b580a0f..7e5a87a 100644
--- a/hw/sd/trace-events
+++ b/hw/sd/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(441)
+
 # hw/sd/milkymist-memcard.c
 milkymist_memcard_memory_read(uint32_t addr, uint32_t value) "addr %08x value 
%08x"
 milkymist_memcard_memory_write(uint32_t addr, uint32_t value) "addr %08x value 
%08x"
diff --git a/hw/sparc/trace-events b/hw/sparc/trace-events
index ab677a3..3701222 100644
--- a/hw/sparc/trace-events
+++ b/hw/sparc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(81)
+
 # hw/sparc/sun4m.c
 sun4m_cpu_interrupt(unsigned int level) "Set CPU IRQ %d"
 sun4m_cpu_reset_interrupt(unsigned int level) "Reset CPU IRQ %d"
diff --git a/hw/timer/trace-events b/hw/timer/trace-events
index 19db4bf..884cce6 100644
--- a/hw/timer/trace-events
+++ b/hw/timer/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(484)
+
 # hw/timer/slavio_timer.c
 slavio_timer_get_out(uint64_t limit, uint32_t counthigh, uint32_t count) 
"limit %"PRIx64" count %x%08x"
 slavio_timer_irq(uint32_t counthigh, uint32_t count) "callback: count %x%08x"
diff --git a/hw/usb/trace-events b/hw/usb/trace-events
index ac2d951..c913c99 100644
--- a/hw/usb/trace-events
+++ b/hw/usb/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(343)
+
 # hw/usb/core.c
 usb_packet_state_change(int bus, const char *port, int ep, void *p, const char 
*o, const char *n) "bus %d, port %s, ep %d, packet %p, state %s -> %s"
 usb_packet_state_fault(int bus, const char *port, int ep, void *p, const char 
*o, const char *n) "bus %d, port %s, ep %d, packet %p, state %s, expected %s"
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 4bb7690..b3898d7 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(108)
+
 # hw/vfio/pci.c
 vfio_intx_interrupt(const char *name, char line) " (%s) Pin %c"
 vfio_intx_eoi(const char *name) " (%s) EOI"
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 6849a44..e5350c6 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(500)
+
 # hw/virtio/virtio.c
 virtqueue_fill(void *vq, const void *elem, unsigned int len, unsigned int idx) 
"vq %p elem %p len %u idx %u"
 virtqueue_flush(void *vq, unsigned int count) "vq %p count %u"
diff --git a/io/trace-events b/io/trace-events
index 8d84eda..910c9b9 100644
--- a/io/trace-events
+++ b/io/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(529)
+
 # io/task.c
 qio_task_new(void *task, void *source, void *func, void *opaque) "Task new 
task=%p source=%p func=%p opaque=%p"
 qio_task_complete(void *task) "Task complete task=%p"
diff --git a/linux-user/trace-events b/linux-user/trace-events
index 80a2e07..e8d4229 100644
--- a/linux-user/trace-events
+++ b/linux-user/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(4)
+
 # linux-user/signal.c
 user_setup_frame(void *env, uint64_t frame_addr) "env=%p frame_addr=%"PRIx64
 user_setup_rt_frame(void *env, uint64_t frame_addr) "env=%p frame_addr=%"PRIx64
diff --git a/migration/trace-events b/migration/trace-events
index 8568dab..43ce7f7 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(9)
+
 # migration/savevm.c
 qemu_loadvm_state_section(unsigned int section_type) "%d"
 qemu_loadvm_state_section_command(int ret) "%d"
diff --git a/net/trace-events b/net/trace-events
index 32a0a8a..49b0174 100644
--- a/net/trace-events
+++ b/net/trace-events
@@ -1,4 +1,6 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(625)
+
 # net/vhost-user.c
 vhost_user_event(const char *chr, int event) "chr: %s got event: %d"
diff --git a/qom/trace-events b/qom/trace-events
index 350fc1f..4c76f43 100644
--- a/qom/trace-events
+++ b/qom/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(675)
+
 # qom/object.c
 object_dynamic_cast_assert(const char *type, const char *target, const char 
*file, int line, const char *func) "%s->%s (%s:%d:%s)"
 object_class_dynamic_cast_assert(const char *type, const char *target, const 
char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 3916c6d..0f4d020 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -114,11 +114,12 @@ def process(events, log, analyzer, read_header=True):
     if read_header:
         read_trace_header(log)
 
-    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
+    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)",
+                                dropped_event_id, 0)
     edict = {dropped_event_id: dropped_event}
 
-    for num, event in enumerate(events):
-        edict[num] = event
+    for event in events:
+        edict[event.global_id] = event
 
     def build_fn(analyzer, event):
         if isinstance(event, str):
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index aebabaf..00d1c89 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -145,6 +145,12 @@ class Event(object):
     ----------
     name : str
         The event name.
+    local_id: int
+        ID of event within the group
+    id_offset: int
+        Offset for event ID
+    global_id: int
+        ID of event globally unique
     fmt : str
         The event format string.
     properties : set(str)
@@ -163,13 +169,17 @@ class Event(object):
 
     _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
 
-    def __init__(self, name, props, fmt, args, orig=None,
+    def __init__(self, name, local_id, id_offset, props, fmt, args, orig=None,
                  event_trans=None, event_exec=None):
         """
         Parameters
         ----------
         name : string
             Event name.
+        local_id: int
+            ID of event within the group
+        id_offset: int
+            Offset for event ID
         props : list of str
             Property names.
         fmt : str, list of str
@@ -185,6 +195,9 @@ class Event(object):
 
         """
         self.name = name
+        self.local_id = local_id
+        self.id_offset = id_offset
+        self.global_id = (self.id_offset << 16) | self.local_id
         self.properties = props
         self.fmt = fmt
         self.args = args
@@ -204,11 +217,11 @@ class Event(object):
 
     def copy(self):
         """Create a new copy."""
-        return Event(self.name, list(self.properties), self.fmt,
+        return Event(self.name, self.local_id, self.id_offset, 
list(self.properties), self.fmt,
                      self.args.copy(), self, self.event_trans, self.event_exec)
 
     @staticmethod
-    def build(line_str):
+    def build(line_str, local_id, id_offset):
         """Build an Event instance from a string.
 
         Parameters
@@ -237,7 +250,7 @@ class Event(object):
         if "tcg" in props and isinstance(fmt, str):
             raise ValueError("Events with 'tcg' property must have two 
formats")
 
-        event = Event(name, props, fmt, args)
+        event = Event(name, local_id, id_offset, props, fmt, args)
 
         # add implicit arguments when using the 'vcpu' property
         import tracetool.vcpu
@@ -251,10 +264,13 @@ class Event(object):
             fmt = self.fmt
         else:
             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
-        return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
-                                          self.name,
-                                          self.args,
-                                          fmt)
+        return "Event('%s %s:%d:%d(%s) %s')" % (
+            " ".join(self.properties),
+            self.name,
+            self.local_id,
+            self.id_offset,
+            self.args,
+            fmt)
 
     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 
@@ -274,6 +290,8 @@ class Event(object):
     def transform(self, *trans):
         """Return a new Event with transformed Arguments."""
         return Event(self.name,
+                     self.local_id,
+                     self.id_offset,
                      list(self.properties),
                      self.fmt,
                      self.args.transform(*trans),
@@ -282,13 +300,26 @@ class Event(object):
 
 def _read_events(fobj):
     events = []
+    id_offset = 0
+    local_id = 0
+    all_id_offsets = []
     for line in fobj:
         if not line.strip():
             continue
         if line.lstrip().startswith('#'):
             continue
 
-        event = Event.build(line)
+        if line.startswith("@id_offset("):
+            id_offset = int(line[11:-2])
+
+            if id_offset in all_id_offsets:
+                raise TracetoolError("ID offset %d already used" % id_offset)
+            all_id_offsets.append(id_offset)
+            local_id = 0
+            continue
+
+        event = Event.build(line, local_id, id_offset)
+        local_id += 1
 
         # transform TCG-enabled events
         if "tcg" not in event.properties:
diff --git a/scripts/tracetool/backend/simple.py 
b/scripts/tracetool/backend/simple.py
index 8c27b68..b4f6ea4 100644
--- a/scripts/tracetool/backend/simple.py
+++ b/scripts/tracetool/backend/simple.py
@@ -80,11 +80,12 @@ def generate_c(event, group):
         '        return;',
         '    }',
         '',
-        '    if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
+        '    if (trace_record_start(&rec, (%(id_offset)d << 16) | 
%(event_id)s, %(size_str)s)) {',
         '        return; /* Trace Buffer Full, Event Dropped ! */',
         '    }',
         cond=cond,
         event_id=event_id,
+        id_offset=event.id_offset,
         size_str=sizestr)
 
     if len(event.args) > 0:
diff --git a/scripts/tracetool/format/simpletrace_stap.py 
b/scripts/tracetool/format/simpletrace_stap.py
index c8b3850..9ec107c 100644
--- a/scripts/tracetool/format/simpletrace_stap.py
+++ b/scripts/tracetool/format/simpletrace_stap.py
@@ -48,7 +48,7 @@ def generate(events, backend, group):
         sizestr = ' + '.join(sizes)
 
         # Generate format string and value pairs for record header and 
arguments
-        fields = [('8b', str(event_id)),
+        fields = [('8b', str((e.id_offset << 16) | event_id)),
                   ('8b', 'gettimeofday_ns()'),
                   ('4b', sizestr),
                   ('4b', 'pid()')]
diff --git a/target-i386/trace-events b/target-i386/trace-events
index ccc49e3..6882f35 100644
--- a/target-i386/trace-events
+++ b/target-i386/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(8)
+
 # target-i386/kvm.c
 kvm_x86_fixup_msi_error(uint32_t gsi) "VT-d failed to remap interrupt for GSI 
%" PRIu32
 kvm_x86_add_msi_route(int virq) "Adding route entry for virq %d"
diff --git a/target-ppc/trace-events b/target-ppc/trace-events
index d37da2b..a81d2e7 100644
--- a/target-ppc/trace-events
+++ b/target-ppc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(676)
+
 # target-ppc/kvm.c
 kvm_failed_spr_set(int str, const char *msg) "Warning: Unable to set SPR %d to 
KVM: %s"
 kvm_failed_spr_get(int str, const char *msg) "Warning: Unable to retrieve SPR 
%d from KVM: %s"
diff --git a/target-s390x/trace-events b/target-s390x/trace-events
index 9589b16..ac2b6ec 100644
--- a/target-s390x/trace-events
+++ b/target-s390x/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(16)
+
 # target-s390x/mmu_helper.c
 get_skeys_nonzero(int rc) "SKEY: Call to get_skeys unexpectedly returned %d"
 set_skeys_nonzero(int rc) "SKEY: Call to set_skeys unexpectedly returned %d"
diff --git a/target-sparc/trace-events b/target-sparc/trace-events
index c75faf9..0022c45 100644
--- a/target-sparc/trace-events
+++ b/target-sparc/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(576)
+
 # target-sparc/mmu_helper.c
 mmu_helper_dfault(uint64_t address, uint64_t context, int mmu_idx, uint32_t 
tl) "DFAULT at %"PRIx64" context %"PRIx64" mmu_idx=%d tl=%d"
 mmu_helper_dprot(uint64_t address, uint64_t context, int mmu_idx, uint32_t tl) 
"DPROT at %"PRIx64" context %"PRIx64" mmu_idx=%d tl=%d"
diff --git a/trace-events b/trace-events
index 1de7e99..08c0b1e 100644
--- a/trace-events
+++ b/trace-events
@@ -25,6 +25,8 @@
 #
 # The <format-string> should be a sprintf()-compatible format string.
 
address@hidden(1)
+
 # thread-pool.c
 thread_pool_submit(void *pool, void *req, void *opaque) "pool %p req %p opaque 
%p"
 thread_pool_complete(void *pool, void *req, void *opaque, int ret) "pool %p 
req %p opaque %p ret %d"
diff --git a/ui/trace-events b/ui/trace-events
index d36dbbb..1649aa1 100644
--- a/ui/trace-events
+++ b/ui/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(27)
+
 # ui/console.c
 console_gfx_new(void) ""
 console_putchar_csi(int esc_param0, int esc_param1, int ch, int nb_esc_params) 
"escape sequence CSI%d;%d%c, %d parameters"
diff --git a/util/trace-events b/util/trace-events
index 111e1de..f83fbde 100644
--- a/util/trace-events
+++ b/util/trace-events
@@ -1,5 +1,7 @@
 # See docs/trace-events.txt for syntax documentation.
 
address@hidden(648)
+
 # util/buffer.c
 buffer_resize(const char *buf, size_t olen, size_t len) "%s: old %zd, new %zd"
 buffer_move_empty(const char *buf, size_t len, const char *from) "%s: %zd 
bytes from %s"
-- 
2.7.4