With current perf framework, this patch adds support and documentation
for more perf events, including cache misses, cache references, cpu cycles,
and instructions.
Signed-off-by: NQiaowei Ren <qiaowei.ren@intel.com>

Introduce a static attr table and refactor virPerfEventEnable() for
general purpose usage.

This patch creates a static table/matrix that converts the VIR_PERF_EVENT_*
events into their respective "attr.type" and "attr.config" so that
virPerfEventEnable doesn't have the switch the calling function passes
by value the 'type'.
Signed-off-by: NQiaowei Ren <qiaowei.ren@intel.com>

Move them to the bottom under the #ifdef code.

So imagine the following. You connect read only to a daemon and
try to fetch stats for a shut off domain, e.g.:

  virsh -r domstats $dom

but all of a sudden, virsh instead of printing the stats throws
the following error at you:

  error: Disconnected from qemu:///system due to I/O error
  error: End of file while reading data: Input/output error

The daemon crashed. This is its backtrace:

#0  0x00007fa43e3751a8 in virPerfEventIsEnabled (perf=0x0, type=VIR_PERF_EVENT_MBMT) at util/virperf.c:241
#1  0x00007fa424a9f042 in qemuDomainGetStatsPerf (driver=0x7fa3f4022a30, dom=0x7fa3f40e24c0, record=0x7fa41c000e20, maxparams=0x7fa4360b38d0, privflags=1) at qemu/qemu_driver.c:19110
#2  0x00007fa424a9f2e7 in qemuDomainGetStats (conn=0x7fa41c001b20, dom=0x7fa3f40e24c0, stats=127, record=0x7fa4360b3970, flags=1) at qemu/qemu_driver.c:19213
#3  0x00007fa424a9f672 in qemuConnectGetAllDomainStats (conn=0x7fa41c001b20, doms=0x7fa41c0017f0, ndoms=1, stats=127, retStats=0x7fa4360b3a50, flags=0) at qemu/qemu_driver.c:19303
#4  0x00007fa43e4e15f6 in virDomainListGetStats (doms=0x7fa41c0017f0, stats=0, retStats=0x7fa4360b3a50, flags=0) at libvirt-domain.c:11615

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f28d1a38700 (LWP 16154)]
0x00007f28da4fa1a8 in virPerfEventIsEnabled (perf=0x0, type=VIR_PERF_EVENT_MBMT) at util/virperf.c:241
241         return event->enabled;

Problem is, shut off domains don't have priv->perf allocated.
Therefore if in frame #1 qemuDomainGetStatsPerf() tries to check
if perf events are enabled, NULL is passed to
virPerfEventIsEnabled() which due to some incredible
implementation dereference it. Fix this by checking whether
passed object is not NULL.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This function is not used anywhere. Moreover, the code that would
use lives in virperf.c and therefore has access to the FD anyway.
Well, for instance virPerfReadEvent is doing just that.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Some Intel processor families (e.g. the Intel Xeon processor E5 v3
family) introduced some RDT (Resource Director Technology) features
to monitor or control shared resource. Among these features, MBM
(Memory Bandwidth Monitoring), which is build on the CMT (Cache
Monitoring Technology) infrastructure, provides OS/VMM a way to
monitor bandwidth from one level of cache to another.

With current perf framework, this patch adds support to perf event
for MBM.
Signed-off-by: NQiaowei Ren <qiaowei.ren@intel.com>

The label is used only for the error path, thus rename cleanup.

Do I really need to explain why?
Well, if read() is interrupted int the middle of reading, we will
never read the rest (even though it's highly unlikely as we are
reading just 8 bytes).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

 * Sync stubbed functions with prototypes
 * Add missing ATTRIBUTE_UNUSED where needed

Pushing under the build breaker rule.

This patch implement a set of interfaces for perf event. Based on
these interfaces, we can implement internal driver API for perf,
and get the results of perf conuter you care about.
Signed-off-by: NQiaowei Ren <qiaowei.ren@intel.com>
Message-id: 1459171833-26416-4-git-send-email-qiaowei.ren@intel.com