[RFC v4][PATCH 0/3] Monitor support for Qemu tracing

[Prerna Saxena <prerna@linux.vnet.ibm.com>]

This set of patches enables trace visualization & control 
via the QEMU monitor. It is based on trace infrastructure posted 
upstream :
( http://lists.gnu.org/archive/html/qemu-devel/2010-05/msg02407.html )

This patchset adds monitor commands :
- info trace : to view current contents of the trace buffer
- info tracepoints : to view all available tracepoints and their state.
- tracepoint NAME on|off : to enable/disable the logging of dataThis is v3 of a set of patches to enable trace visualization & control 
via the QEMU monitor. 

Changelog from v3:
1. As suggested, it replaces a hash-based search of tracepoints 
with a linear search.
2. Static initialization of trace event array.
3. Cleanups.

Changelog from v2:
1. Clean-ups, particularly relating to export of tdb_hash().

Changelog from v1:
1. Command 'info trace' is used to view current contents of buffer, in 
place of 'trace'.
2. Cleanups


Todos :
1. Integration with QMP
2. More tracepoints need to be added for instrumenting other qemu components
 such as virtio drivers, etc.

-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India