| Message ID | 20220921164521.2858932-2-xiaoyao.li@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Fix VM entry failure on PT_MODE_HOST_GUEST while host is using PT | expand |
On Thursday, September 22, 2022 12:45 AM, Li, Xiaoyao wrote: > KVM needs them to disable/enable an Intel PT perf event before vm-entry/after > vm-exit. I would explain more in the commit here: Export perf_event_disable_local and perf_event_enable_local for perf users to disable and enable perf events on the current local CPU. One usage is in PT virtualization by KVM: - before VMEnter to guest, KVM calls perf_event_disable_local to disable the host PT event running on the current CPU, and this reuses the PT driver to save the related h/w states. - after VMExit to host, KVM calls perf_event_enable_local to resume the host PT event on the current CPU by having the PT driver load the previously saved states into h/w. > > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> > --- > include/linux/perf_event.h | 1 + > kernel/events/core.c | 7 +++++++ > 2 files changed, 8 insertions(+) > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index > ee8b9ecdc03b..fc5f3952d6a2 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -1472,6 +1472,7 @@ extern int > perf_swevent_get_recursion_context(void); > extern void perf_swevent_put_recursion_context(int rctx); extern u64 > perf_swevent_set_period(struct perf_event *event); extern void > perf_event_enable(struct perf_event *event); > +extern void perf_event_enable_local(struct perf_event *event); > extern void perf_event_disable(struct perf_event *event); extern void > perf_event_disable_local(struct perf_event *event); extern void > perf_event_disable_inatomic(struct perf_event *event); diff --git > a/kernel/events/core.c b/kernel/events/core.c index > 2621fd24ad26..8324bb99c6bf 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -2446,6 +2446,7 @@ void perf_event_disable_local(struct perf_event > *event) { > event_function_local(event, __perf_event_disable, NULL); } > +EXPORT_SYMBOL_GPL(perf_event_disable_local); > > /* > * Strictly speaking kernel users cannot create groups and therefore this @@ > -2984,6 +2985,12 @@ static void _perf_event_enable(struct perf_event *event) > event_function_call(event, __perf_event_enable, NULL); } > > +void perf_event_enable_local(struct perf_event *event) { > + event_function_local(event, __perf_event_enable, NULL); } > +EXPORT_SYMBOL_GPL(perf_event_enable_local); > + > /* > * See perf_event_disable(); > */ > -- > 2.27.0
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ee8b9ecdc03b..fc5f3952d6a2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1472,6 +1472,7 @@ extern int perf_swevent_get_recursion_context(void); extern void perf_swevent_put_recursion_context(int rctx); extern u64 perf_swevent_set_period(struct perf_event *event); extern void perf_event_enable(struct perf_event *event); +extern void perf_event_enable_local(struct perf_event *event); extern void perf_event_disable(struct perf_event *event); extern void perf_event_disable_local(struct perf_event *event); extern void perf_event_disable_inatomic(struct perf_event *event); diff --git a/kernel/events/core.c b/kernel/events/core.c index 2621fd24ad26..8324bb99c6bf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2446,6 +2446,7 @@ void perf_event_disable_local(struct perf_event *event) { event_function_local(event, __perf_event_disable, NULL); } +EXPORT_SYMBOL_GPL(perf_event_disable_local); /* * Strictly speaking kernel users cannot create groups and therefore this @@ -2984,6 +2985,12 @@ static void _perf_event_enable(struct perf_event *event) event_function_call(event, __perf_event_enable, NULL); } +void perf_event_enable_local(struct perf_event *event) +{ + event_function_local(event, __perf_event_enable, NULL); +} +EXPORT_SYMBOL_GPL(perf_event_enable_local); + /* * See perf_event_disable(); */
KVM needs them to disable/enable an Intel PT perf event before vm-entry/after vm-exit. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> --- include/linux/perf_event.h | 1 + kernel/events/core.c | 7 +++++++ 2 files changed, 8 insertions(+)