From 39447b386c846bbf1c56f6403c5282837486200f Mon Sep 17 00:00:00 2001 From: "Zhang, Yanmin" Date: Mon, 19 Apr 2010 13:32:41 +0800 Subject: [PATCH] perf: Enhance perf to allow for guest statistic collection from host Below patch introduces perf_guest_info_callbacks and related register/unregister functions. Add more PERF_RECORD_MISC_XXX bits meaning guest kernel and guest user space. Signed-off-by: Zhang Yanmin Signed-off-by: Avi Kivity --- arch/x86/include/asm/perf_event.h | 15 ++++----------- arch/x86/kernel/cpu/perf_event.c | 31 +++++++++++++++++++++++++++++++ include/linux/perf_event.h | 21 ++++++++++++++++++++- kernel/perf_event.c | 23 ++++++++++++++++++++++- 4 files changed, 77 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index f6d43dbfd8e7..254883d0c7e0 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -135,17 +135,10 @@ extern void perf_events_lapic_init(void); */ #define PERF_EFLAGS_EXACT (1UL << 3) -#define perf_misc_flags(regs) \ -({ int misc = 0; \ - if (user_mode(regs)) \ - misc |= PERF_RECORD_MISC_USER; \ - else \ - misc |= PERF_RECORD_MISC_KERNEL; \ - if (regs->flags & PERF_EFLAGS_EXACT) \ - misc |= PERF_RECORD_MISC_EXACT; \ - misc; }) - -#define perf_instruction_pointer(regs) ((regs)->ip) +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) #else static inline void init_hw_perf_events(void) { } diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 626154a9f535..2ea78abf69d9 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1720,6 +1720,11 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) { struct perf_callchain_entry *entry; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* TODO: We don't support guest os callchain now */ + return NULL; + } + if (in_nmi()) entry = &__get_cpu_var(pmc_nmi_entry); else @@ -1743,3 +1748,29 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski regs->cs = __KERNEL_CS; local_save_flags(regs->flags); } + +unsigned long perf_instruction_pointer(struct pt_regs *regs) +{ + unsigned long ip; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) + ip = perf_guest_cbs->get_guest_ip(); + else + ip = instruction_pointer(regs); + return ip; +} + +unsigned long perf_misc_flags(struct pt_regs *regs) +{ + int misc = 0; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + misc |= perf_guest_cbs->is_user_mode() ? + PERF_RECORD_MISC_GUEST_USER : + PERF_RECORD_MISC_GUEST_KERNEL; + } else + misc |= user_mode(regs) ? PERF_RECORD_MISC_USER : + PERF_RECORD_MISC_KERNEL; + if (regs->flags & PERF_EFLAGS_EXACT) + misc |= PERF_RECORD_MISC_EXACT; + + return misc; +} diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index bf896d0b2e9c..24de5f181a41 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -288,11 +288,13 @@ struct perf_event_mmap_page { __u64 data_tail; /* user-space written tail */ }; -#define PERF_RECORD_MISC_CPUMODE_MASK (3 << 0) +#define PERF_RECORD_MISC_CPUMODE_MASK (7 << 0) #define PERF_RECORD_MISC_CPUMODE_UNKNOWN (0 << 0) #define PERF_RECORD_MISC_KERNEL (1 << 0) #define PERF_RECORD_MISC_USER (2 << 0) #define PERF_RECORD_MISC_HYPERVISOR (3 << 0) +#define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0) +#define PERF_RECORD_MISC_GUEST_USER (5 << 0) #define PERF_RECORD_MISC_EXACT (1 << 14) /* @@ -446,6 +448,12 @@ enum perf_callchain_context { # include #endif +struct perf_guest_info_callbacks { + int (*is_in_guest) (void); + int (*is_user_mode) (void); + unsigned long (*get_guest_ip) (void); +}; + #ifdef CONFIG_HAVE_HW_BREAKPOINT #include #endif @@ -932,6 +940,12 @@ static inline void perf_event_mmap(struct vm_area_struct *vma) __perf_event_mmap(vma); } +extern struct perf_guest_info_callbacks *perf_guest_cbs; +extern int perf_register_guest_info_callbacks( + struct perf_guest_info_callbacks *); +extern int perf_unregister_guest_info_callbacks( + struct perf_guest_info_callbacks *); + extern void perf_event_comm(struct task_struct *tsk); extern void perf_event_fork(struct task_struct *tsk); @@ -1001,6 +1015,11 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, static inline void perf_bp_event(struct perf_event *event, void *data) { } +static inline int perf_register_guest_info_callbacks +(struct perf_guest_info_callbacks *) {return 0; } +static inline int perf_unregister_guest_info_callbacks +(struct perf_guest_info_callbacks *) {return 0; } + static inline void perf_event_mmap(struct vm_area_struct *vma) { } static inline void perf_event_comm(struct task_struct *tsk) { } static inline void perf_event_fork(struct task_struct *tsk) { } diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 07b7a435bf03..9dbe8cdaf145 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -2797,6 +2797,27 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski } +/* + * We assume there is only KVM supporting the callbacks. + * Later on, we might change it to a list if there is + * another virtualization implementation supporting the callbacks. + */ +struct perf_guest_info_callbacks *perf_guest_cbs; + +int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = cbs; + return 0; +} +EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); + +int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = NULL; + return 0; +} +EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); + /* * Output */ @@ -3749,7 +3770,7 @@ void __perf_event_mmap(struct vm_area_struct *vma) .event_id = { .header = { .type = PERF_RECORD_MMAP, - .misc = 0, + .misc = PERF_RECORD_MISC_USER, /* .size */ }, /* .pid */ -- 2.34.1