[PATCH v3] Support CPU-list parsing in xentrace.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

Hey George and Ian,

Since v2 [http://lists.xen.org/archives/html/xen-devel/2014-06/msg01835.html]
 - Redid the code per George's feedback
 - Expanded the xc_cpumap_* calls so that we have an 'setbit' variant.


The purpose of these patches is  to allow users of xentrace to narrow
down a specific CPU without having to figure out a bit mask. They
fix the limitation of the bit mask which is it can only do up to 32-bits
- which on large machines (say 120CPUs), you can't selectively trace anything
past 32CPUs.

The code expands the -c parameter where you can do -c <starting cpu>-<end cpu>
or -c <cpu1>,<cpu2> or a combination of them. There is also the mode of
automatic detection, such as: -c -,<cpu2> (so it will assume up to cpu2 - so
0,1, and 2 CPU), or the inverse: -c <cpu2>- (which will figure the max cpus and
do it from cpu2 up to maximum cpu).

This along with 'xl vcpu-list' makes it extremely easy to trace a specific
guest (if pinned).

You can still use the -c 0x<some hex value> option if you prefer.

The patches are also at my git tree:

 git://xenbits.xen.org/people/konradwilk/xen.git xentrace.v3


 tools/libxc/include/xenctrl.h |  16 ++-
 tools/libxc/xc_misc.c         |  16 +++
 tools/libxc/xc_tbuf.c         |  26 +++--
 tools/xentrace/xentrace.8     |  33 +++++-
 tools/xentrace/xentrace.c     | 240 ++++++++++++++++++++++++++++++++++++++----
 5 files changed, 300 insertions(+), 31 deletions(-)

Konrad Rzeszutek Wilk (3):
      libxl/cpumap: Add xc_cpumap_[setcpu, clearcpu, testcpu] to complement xc_cpumap_alloc.
      libxc/xentrace: Replace xc_tbuf_set_cpu_mask with CPU mask with xc_cpumap_t instead of uint32_t
      xentrace: Implement cpu mask range parsing of human values (-c).