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>
kvm_stat uses syscall() to call perf_event_open(). If this function
call fails, the returned value is -1, which doesn't tell the details
of such failure (i.e. ENOSYS or EINVAL). This patch retrieves errno
and prints it when syscall() fails. The error message will look like
"Exception: perf_event_open failed, errno = 38".
Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch updates the exit reasons for x86_vmx, x86_svm, and userspace
to the latest definition.
Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch enables aarch64 support for kvm_stat. The platform detection
is based on OS uname.
Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add support for powerpc platforms. We use uname -m, which allows us to
detect ppc, ppc64 and ppc64le/el.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unfortunately ioctl numbers are platform specific, so abstract them out
of the code so they can be overridden. As it happens x86 and s390 share
the same values, so nothing needs to change yet.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The current platform detection is a little bit messy. We look for lines
in /proc/cpuinfo starting with 'flags' OR 'vendor-id', and scan both
for values we know will only occur in one or the other. We also keep
scanning once we've found a value, which could be a feature, but isn't
in this case.
We'd also like to add another platform, powerpc, which will just make it
worse. So clean it up in preparation.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In kvm_stat we have a dictionary of exit reasons for s390. Firstly these
are not s390 specific, they are the generic exit reasons. So rename the
dictionary to reflect that, and add it separately to filters[].
Secondly, the values are defined using hex, but in the kernel header
they are decimal. That means values above 9 in kvm_stat are incorrect.
While we're there, fix the whitespace to match the rest of the file.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In kvm_stat we grovel through /sys to find out how many cpus are in the
system. However if a cpu is offline it will still be present in /sys,
and the perf_event_open() will fail.
Modify the logic to only return online cpus. We need to be careful on
systems which don't support cpu hotplug, the online file will not be
present at all.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The old stats contain information not available in the tracepoints.
By default, keep the old behavior, but allow choosing which set of stats
to present, or even both.
Inspired by a patch from Marcelo Tosatti.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Correct sys_perf_event_open syscall number for s390 architecture
- the hardcoded syscall number 298 is for x86 but should
be different for other architectures.
In case we figure out via /proc/cpuinfo that we are running
on s390 the appropriate syscall number is used from map
syscall_numbers; other architectures can extend this.
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Add s390_exit_reasons so kvm_stat doesn't crash when called on s390.
Look for 'vendor_id' in /proc/cpuinfo as well, instead of just for
'flags', so we can determine if we run on S390.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
