Introduce rules in the top level Makefile that are able to generate
trace.[ch] files in every subdirectory which has a trace-events file.

The top level directory is handled specially, so instead of creating
trace.h, it creates trace-root.h. This allows sub-directories to
include the top level trace-root.h file, without ambiguity wrt to
the trace.g file in the current sub-dir.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-7-berrange@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Fixes potential corruption when a vCPU is hot-(un)plugged while
initializing the current one.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 148278747515.1404.6538173443841279200.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-11-git-send-email-berrange@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-7-git-send-email-berrange@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This converts the HMP/QMP monitor API implementations
and some internal trace control methods to use the new
trace event iterator APIs.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 1475588159-30598-5-git-send-email-berrange@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signals the hot-plugging of a new virtual (guest) CPU.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147428971313.15111.18023030883528426840.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147428970768.15111.7664565956870423529.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

An explicit if/else is clearer than arithmetic assuming #true is 1,
while the compiler should be able to generate just as optimal code.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147194273830.26836.5875729707953474838.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147194273191.26836.14423079546263831356.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Each vCPU gets a 'trace_dstate' bitmap to control the per-vCPU dynamic
tracing state of events with the 'vcpu' property.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>