From 75e424620a4f8247e8877c224d0457efadf88201 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 23 Jan 2013 16:52:18 +0000 Subject: [PATCH] arm64: perf: add guest vs host discrimination Add minimal guest support to perf, so it can distinguish whether the PMU interrupt was in the host or the guest, as well as collecting some very basic information (guest PC, user vs kernel mode). This is not feature complete though, as it doesn't support backtracing in the guest. Based on the x86 implementation, tested with KVM/arm64. Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/perf_event.h | 7 +++++- arch/arm64/kernel/perf_event.c | 37 +++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h index a6fffd511c5e..d26d1d53c0d7 100644 --- a/arch/arm64/include/asm/perf_event.h +++ b/arch/arm64/include/asm/perf_event.h @@ -17,6 +17,11 @@ #ifndef __ASM_PERF_EVENT_H #define __ASM_PERF_EVENT_H -/* It's quiet around here... */ +#ifdef CONFIG_HW_PERF_EVENTS +struct pt_regs; +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) +#endif #endif diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index f7073c7b1ca9..1e49e5eb81e9 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -1331,6 +1331,11 @@ void perf_callchain_user(struct perf_callchain_entry *entry, { struct frame_tail __user *tail; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* We don't support guest os callchain now */ + return; + } + tail = (struct frame_tail __user *)regs->regs[29]; while (entry->nr < PERF_MAX_STACK_DEPTH && @@ -1355,8 +1360,40 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry, { struct stackframe frame; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* We don't support guest os callchain now */ + return; + } + frame.fp = regs->regs[29]; frame.sp = regs->sp; frame.pc = regs->pc; walk_stackframe(&frame, callchain_trace, entry); } + +unsigned long perf_instruction_pointer(struct pt_regs *regs) +{ + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) + return perf_guest_cbs->get_guest_ip(); + + return instruction_pointer(regs); +} + +unsigned long perf_misc_flags(struct pt_regs *regs) +{ + int misc = 0; + + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + if (perf_guest_cbs->is_user_mode()) + 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; +} -- GitLab