Commit abd562df authored by Like Xu's avatar Like Xu Committed by Peter Zijlstra
Browse files

x86/perf: Use static_call for x86_pmu.guest_get_msrs 



Clean up that CONFIG_RETPOLINE crud and replace the
indirect call x86_pmu.guest_get_msrs with static_call().

Reported-by: default avatarkernel test robot <lkp@intel.com>
Suggested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarLike Xu <like.xu@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210125121458.181635-1-like.xu@linux.intel.com
parent 9a7832ce

arch/x86/events/core.c

+20 −0
Original line number Diff line number Diff line
@@ -81,6 +81,8 @@ DEFINE_STATIC_CALL_NULL(x86_pmu_swap_task_ctx, *x86_pmu.swap_task_ctx); 
DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs,   *x86_pmu.drain_pebs);

DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);



DEFINE_STATIC_CALL_NULL(x86_pmu_guest_get_msrs,  *x86_pmu.guest_get_msrs);



u64 __read_mostly hw_cache_event_ids

				[PERF_COUNT_HW_CACHE_MAX]

				[PERF_COUNT_HW_CACHE_OP_MAX]
@@ -665,6 +667,12 @@ void x86_pmu_disable_all(void) 
	}

}



struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)

{

	return static_call(x86_pmu_guest_get_msrs)(nr);

}

EXPORT_SYMBOL_GPL(perf_guest_get_msrs);



/*

 * There may be PMI landing after enabled=0. The PMI hitting could be before or

 * after disable_all.
@@ -1923,6 +1931,8 @@ static void x86_pmu_static_call_update(void) 


	static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);

	static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);



	static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs);

}



static void _x86_pmu_read(struct perf_event *event)
@@ -1930,6 +1940,13 @@ static void _x86_pmu_read(struct perf_event *event) 
	x86_perf_event_update(event);

}



static inline struct perf_guest_switch_msr *

perf_guest_get_msrs_nop(int *nr)

{

	*nr = 0;

	return NULL;

}



static int __init init_hw_perf_events(void)

{

	struct x86_pmu_quirk *quirk;
@@ -2001,6 +2018,9 @@ static int __init init_hw_perf_events(void) 
	if (!x86_pmu.read)

		x86_pmu.read = _x86_pmu_read;



	if (!x86_pmu.guest_get_msrs)

		x86_pmu.guest_get_msrs = perf_guest_get_msrs_nop;



	x86_pmu_static_call_update();



	/*

arch/x86/events/intel/core.c

+0 −20
Original line number Diff line number Diff line
@@ -3680,26 +3680,6 @@ static int intel_pmu_hw_config(struct perf_event *event) 
	return 0;

}



#ifdef CONFIG_RETPOLINE

static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr);

static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr);

#endif



struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)

{

#ifdef CONFIG_RETPOLINE

	if (x86_pmu.guest_get_msrs == intel_guest_get_msrs)

		return intel_guest_get_msrs(nr);

	else if (x86_pmu.guest_get_msrs == core_guest_get_msrs)

		return core_guest_get_msrs(nr);

#endif

	if (x86_pmu.guest_get_msrs)

		return x86_pmu.guest_get_msrs(nr);

	*nr = 0;

	return NULL;

}

EXPORT_SYMBOL_GPL(perf_guest_get_msrs);



static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr)

{

	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

arch/x86/include/asm/perf_event.h

+1 −5
Original line number Diff line number Diff line
@@ -483,11 +483,7 @@ static inline void perf_check_microcode(void) { } 
extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr);

extern int x86_perf_get_lbr(struct x86_pmu_lbr *lbr);

#else

static inline struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)

{

	*nr = 0;

	return NULL;

}

struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr);

static inline int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)

{

	return -1;