Commit Graph

34 Commits

Author SHA1 Message Date
Daniel P. Berrange ca3fa0e88f trace: dynamically allocate event IDs at runtime
Instead of having the code generator assign event IDs and
event VCPU IDs, assign them when the events are registered
at runtime. This will allow code to be generated from
individual trace-events without having to figure out
globally unique numbering at build time.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-16-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:54:52 +02:00
Daniel P. Berrange b7d48952c3 trace: dynamically allocate trace_dstate in CPUState
The CPUState struct has a bitmap tracking which VCPU
events are currently active. This is indexed based on
the event ID values, and sized according the maximum
TraceEventVCPUID enum value.

When we start dynamically assigning IDs at runtime,
we can't statically declare a bitmap without making
an assumption about the max event count. This problem
can be solved by dynamically allocating the per-CPU
dstate bitmap.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-15-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:54:52 +02:00
Daniel P. Berrange fe4db84d49 trace: provide mechanism for registering trace events
Remove the notion of there being a single global array
of trace events, by introducing a method for registering
groups of events.

The module_call_init() needs to be invoked at the start
of any program that wants to make use of the trace
support. Currently this covers system emulators qemu-nbd,
qemu-img and qemu-io.

[Squashed the following fix from Daniel P. Berrange
<berrange@redhat.com>:

linux-user/bsd-user: initialize trace events subsystem

The bsd-user/linux-user programs make use of the CPU emulation
code and this now requires that the trace events subsystem
is enabled, otherwise it'll crash trying to allocate an empty
trace events bitmap for the CPU object.

--Stefan]

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-14-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:52:50 +02:00
Daniel P. Berrange ef4c9fc854 trace: remove the TraceEventID and TraceEventVCPUID enums
The TraceEventID and TraceEventVCPUID enums constants are
no longer actually used for anything critical.

The TRACE_EVENT_COUNT limit is used to determine the size
of the TraceEvents array, and can be removed if we just
NULL terminate the array instead.

The TRACE_VCPU_EVENT_COUNT limit is used as a magic value
for marking non-vCPU events, and also for declaring the
size of the trace dstate mask in the CPUState struct.
The former usage can be replaced by a dedicated constant
TRACE_EVENT_VCPU_NONE, defined as (uint32_t)-1. For the
latter usage, we can simply define a constant for the
number of VCPUs, avoiding the need for the full enum.

The only other usages of the enum values can be replaced
by accesing the id/vcpu_id fields via the named TraceEvent
structs.

Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-11-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
Daniel P. Berrange 79218be42b trace: give each trace event a named TraceEvent struct
Currently we only expose a TraceEvent array, which must
be indexed via the TraceEventID enum constants. This
changes the generator to expose a named TraceEvent
instance for each event, with an _EVENT suffix.

Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-10-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
Daniel P. Berrange 9397740244 trace: remove global 'uint16 dstate[]' array
Instead of having a global dstate array, declare a single
'uint16 TRACE_${EVENT_NAME}_DSTATE' variable for each
trace event. Record a pointer to this variable in the
TraceEvent struct too.

By turning trace_event_get_state_dynamic_by_id into a
macro, this still hits the fast path, and cache affinity
is ensured by declaring all the uint16 vars adjacent to
each other.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-7-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
Daniel P. Berrange 599ab2f241 trace: remove some now unused functions
The trace_event_count, trace_event_id and
trace_event_pattern methods are no longer required
now that everything is using the iterator APIs

The trace_event_set_state and trace_event_set_vcpu_state
macros were also unused.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-6-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
Daniel P. Berrange 0d4e995c73 trace: convert code to use event iterators
This converts the HMP/QMP monitor API implementations
and some internal trace control methods to use the new
trace event iterator APIs.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 1475588159-30598-5-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
Daniel P. Berrange 6a1b0f3aea trace: add trace event iterator APIs
Currently methods which want to iterate over trace events,
do so using the trace_event_count() and trace_event_id()
methods. This leaks the concept of a single ID enum to
the callers. There is an alternative trace_event_pattern()
method which can be used in an iteration context, but its
design is stateless, so is not easy to expand it in the
future.

This defines a formal iterator API will provide a future-
proof way of iterating over events.

The iterator is also able to apply a pattern match filter
to events, further removing the need for the pattern

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-4-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:53 +02:00
Lluís Vilanova 2bfe11c8fa trace: Properly initialize dynamic event states in hot-plugged vCPUs
Every time a vCPU is hot-plugged, it will "inherit" its tracing state
from the global state array. That is, if *any* existing vCPU has an
event enabled, new vCPUs will have too.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147428970768.15111.7664565956870423529.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-28 19:17:55 +01:00
Lluís Vilanova a4d50b1d2a trace: Remove 'trace_events_dstate_init'
Removes the event state array used for early initialization. Since only
events with the "vcpu" property need a late initialization fixup,
threats their initialization specially.

Assumes that the user won't touch the state of "vcpu" events between
early and late initialization (e.g., through QMP).

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147194273191.26836.14423079546263831356.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05 13:47:01 -04:00
Paul Durrant 0a85241756 trace: add syslog tracing backend
This patch adds a tracing backend which sends output using syslog().
The syslog backend is limited to POSIX compliant systems.

openlog() is called with facility set to LOG_DAEMON, with the LOG_PID
option. Trace events are logged at level LOG_INFO.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Message-id: 1470318254-29989-1-git-send-email-paul.durrant@citrix.com
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05 13:47:01 -04:00
Lluís Vilanova 4815185902 trace: Add per-vCPU tracing states for events with the 'vcpu' property
Each vCPU gets a 'trace_dstate' bitmap to control the per-vCPU dynamic
tracing state of events with the 'vcpu' property.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-18 18:23:12 +01:00
Denis V. Lunev e9e0bb2af2 trace: move qemu_trace_opts to trace/control.c
The patch also creates trace_opt_parse() helper in trace/control.c to reuse
this code in next patches for qemu-nbd and qemu-io.

The patch also makes trace_init_events() static, as this call is not used
outside the module anymore.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1466174654-30130-4-git-send-email-den@openvz.org
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-28 21:14:12 +01:00
Markus Armbruster daa76aa416 log: Fix qemu_set_log_filename() error handling
When qemu_set_log_filename() detects an invalid file name, it reports
an error, closes the log file (if any), and starts logging to stderr
(unless daemonized or nothing is being logged).

This is wrong.  Asking for an invalid log file on the command line
should be fatal.  Asking for one in the monitor should fail without
messing up an existing logfile.

Fix by converting qemu_set_log_filename() to Error.  Pass it
&error_fatal, except for hmp_logfile report errors.

This also permits testing without a subprocess, so do that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1466011636-6112-4-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-20 16:39:08 +02:00
Denis V. Lunev acc6809ddc trace: do not always call exit() in trace_enable_events
The problem is that
  virsh qemu-monitor-command --hmp VM log trace:help
forces QEMU to exit even when running VM normally.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1458128212-4197-2-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-03-31 09:48:59 +01:00
Veronia Bahaa f348b6d1a5 util: move declarations out of qemu-common.h
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)

Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:17 +01:00
Peter Maydell d38ea87ac5 all: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
2016-02-04 17:41:30 +00:00
Paolo Bonzini ed7f5f1d8d trace: convert stderr backend to log
[Also update .travis.yml --enable-trace-backends=stderr
--Stefan]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-10-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 10:37:10 +00:00
Paolo Bonzini e9527dd399 trace: add "-trace help"
Print a list of trace points

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-7-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:09 +00:00
Paolo Bonzini 10578a257d trace: add "-trace enable=..."
Allow enabling events without going through a file, for example:

   qemu-system-x86_64 -trace bdrv_aio_writev -trace bdrv_aio_readv

or with globbing too:

   qemu-system-x86_64 -trace 'bdrv_aio_*'

if an appropriate backend is enabled (simple, stderr, ftrace).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-6-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:09 +00:00
Paolo Bonzini 41fc57e44e trace: split trace_init_file out of trace_init_backends
This is cleaner, and improves error reporting with -daemonize.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-4-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:09 +00:00
Paolo Bonzini 45bd0b41bd trace: split trace_init_events out of trace_init_backends
This is cleaner and has two advantages.  First, it improves error
reporting with -daemonize.  Second, multiple "-trace events" options
now cumulate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-3-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:09 +00:00
Paolo Bonzini 585ec7273e trace: track enabled events in a separate array
This is more cache friendly on the fast path, where we already have
the event id available.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:09 +00:00
Paolo Bonzini 43b48cfc3e trace: count number of enabled events
This lets trace_event_get_state_dynamic quickly return false.  Right
now there is hardly any benefit because there are also many assertions
and indirections, but the next patch will streamline all of this.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03 09:19:08 +00:00
Gonglei 81b07353c5 Remove superfluous '\n' around error_report()
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-03-10 08:15:33 +03:00
Lluís Vilanova 14101d028d trace: [hmp] Reimplement "trace-event" and "info trace-events" using QMP
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825112002.31112.60143.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-26 09:34:38 +01:00
Alexey Kardashevskiy a35d9be622 trace: Replace fprintf with error_report and print location
This replaces fprintf(stderr) with error_report.

This moves local variables to the beginning of the function to comply
with QEMU's coding style.

Suggested-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Lluís Vilanova 5b808275f3 trace: Multi-backend tracing
Adds support to compile QEMU with multiple tracing backends at the same time.

For example, you can compile QEMU with:

  $ ./configure --enable-trace-backends=ftrace,dtrace

Where 'ftrace' can be handy for having an in-flight record of events, and 'dtrace' can be later used to extract more information from the system.

This patch allows having both available without recompiling QEMU.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Alexey Kardashevskiy 82432638eb trace: Replace error with warning if event is not defined
At the moment QEMU exits if trace point is not defined which makes
a developer life harder if he has to switch between branches with
different traces implemented.

This replaces error+exit wit WARNING if the tracepoint does not exist or
not traceable.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Lluís Vilanova b1bae816c4 trace: Provide a detailed event control interface
This interface decouples event obtaining from interaction.

Events can be obtained through three different methods:

* identifier
* name
* simple wildcard pattern

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-28 14:19:57 +01:00
Gerd Hoffmann ddde8acc98 trace: allow disabling events in events file
Disable trace events prefixed with a '-'.  Useful
to enable a group of tracepoints with exceptions,
like this:

  usb_xhci_port_*
  -usb_xhci_port_read

which will enable all xhci port tracepoints except reads.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-16 13:12:13 +01:00
Alexey Kardashevskiy 794b1f962e trace: added ability to comment out events in the list
It is convenient for debug to be able to switch on/off some events easily.
The only possibility now is to remove event name from the file completely
and type it again when we want it back.

The patch adds '#' symbol handling as a comment specifier.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-19 11:30:37 +01:00
Lluís 23d15e860b trace: add "-trace events" argument to control initial state
The "-trace events" argument can be used to provide a file with a list of trace
event names that will be enabled prior to starting execution, thus providing
early tracing.

This saves the user from manually toggling event states through the monitor
interface or whichever backend-specific interface.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
2011-09-01 10:34:54 +01:00