Commit 5bb5ccb3 authored by Quan Zhou's avatar Quan Zhou Committed by Anup Patel
Browse files

riscv: perf: add guest vs host distinction 



Introduce basic guest support in perf, enabling it to distinguish
between PMU interrupts in the host or guest, and collect
fundamental information.

Signed-off-by: default avatarQuan Zhou <zhouquan@iscas.ac.cn>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/a67d527dc1b11493fe11f7f53584772fdd983744.1728957131.git.zhouquan@iscas.ac.cn


Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 81983758

arch/riscv/include/asm/perf_event.h

+6 −0
Original line number Diff line number Diff line
@@ -8,7 +8,11 @@ 
#ifndef _ASM_RISCV_PERF_EVENT_H

#define _ASM_RISCV_PERF_EVENT_H



#ifdef CONFIG_PERF_EVENTS

#include <linux/perf_event.h>

extern unsigned long perf_instruction_pointer(struct pt_regs *regs);

extern unsigned long perf_misc_flags(struct pt_regs *regs);

#define perf_misc_flags(regs) perf_misc_flags(regs)

#define perf_arch_bpf_user_pt_regs(regs) (struct user_regs_struct *)regs



#define perf_arch_fetch_caller_regs(regs, __ip) { \
@@ -17,4 +21,6 @@ 
	(regs)->sp = current_stack_pointer; \

	(regs)->status = SR_PP; \

}

#endif



#endif /* _ASM_RISCV_PERF_EVENT_H */

arch/riscv/kernel/perf_callchain.c

+38 −0
Original line number Diff line number Diff line
@@ -28,11 +28,49 @@ static bool fill_callchain(void *entry, unsigned long pc) 
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,

			 struct pt_regs *regs)

{

	if (perf_guest_state()) {

		/* TODO: We don't support guest os callchain now */

		return;

	}



	arch_stack_walk_user(fill_callchain, entry, regs);

}



void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,

			   struct pt_regs *regs)

{

	if (perf_guest_state()) {

		/* TODO: We don't support guest os callchain now */

		return;

	}



	walk_stackframe(NULL, regs, fill_callchain, entry);

}



unsigned long perf_instruction_pointer(struct pt_regs *regs)

{

	if (perf_guest_state())

		return perf_guest_get_ip();



	return instruction_pointer(regs);

}



unsigned long perf_misc_flags(struct pt_regs *regs)

{

	unsigned int guest_state = perf_guest_state();

	unsigned long misc = 0;



	if (guest_state) {

		if (guest_state & PERF_GUEST_USER)

			misc |= PERF_RECORD_MISC_GUEST_USER;

		else

			misc |= PERF_RECORD_MISC_GUEST_KERNEL;

	} else {

		if (user_mode(regs))

			misc |= PERF_RECORD_MISC_USER;

		else

			misc |= PERF_RECORD_MISC_KERNEL;

	}



	return misc;

}