qemu/scripts/kvm
Wei Huang fc116efad0 kvm_stat: Add RESET support for perf event ioctl
While running kvm_stat using tracepoint on ARM64 hardware (e.g. "kvm_stat
-1 -t"), the initial values of some kvm_userspace_exit counters were found
to be very suspecious. For instance the tracing tool showed that S390_TSCH
was called many times on ARM64 machine, which apparently was wrong.

This patch adds RESET ioctl support for perf monitoring. Before calling
ioctl to enable a perf event, this patch resets the counter first. With
this patch, the init counter values become correct on ARM64 hardware.

Example:

==== before patch ====
kvm_userspace_exit(S390_SIEIC)      1426         0
kvm_userspace_exit(S390_TSCH)       339         0

==== after patch ====
kvm_userspace_exit(S390_SIEIC)         0         0
kvm_userspace_exit(S390_TSCH)         0         0

Signed-off-by: Wei Huang <wei@redhat.com>
2015-01-26 12:27:05 +01:00
..
kvm_flightrecorder kvm: add flightrecorder script 2012-04-12 19:01:41 -03:00
kvm_stat kvm_stat: Add RESET support for perf event ioctl 2015-01-26 12:27:05 +01:00
vmxcap vmxcap: Update according to SDM of September 2014 2014-09-26 21:08:56 +04:00