From b9f5621c9547dd787900f005a9e1c3d5712de512 Mon Sep 17 00:00:00 2001 From: Like Xu Date: Thu, 11 Nov 2021 02:07:27 +0000 Subject: perf/core: Rework guest callbacks to prepare for static_call support To prepare for using static_calls to optimize perf's guest callbacks, replace ->is_in_guest and ->is_user_mode with a new multiplexed hook ->state, tweak ->handle_intel_pt_intr to play nice with being called when there is no active guest, and drop "guest" from ->get_guest_ip. Return '0' from ->state and ->handle_intel_pt_intr to indicate "not in guest" so that DEFINE_STATIC_CALL_RET0 can be used to define the static calls, i.e. no callback == !guest. [sean: extracted from static_call patch, fixed get_ip() bug, wrote changelog] Suggested-by: Peter Zijlstra (Intel) Originally-by: Peter Zijlstra (Intel) Signed-off-by: Like Xu Signed-off-by: Zhu Lingshan Signed-off-by: Sean Christopherson Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Boris Ostrovsky Reviewed-by: Paolo Bonzini Link: https://lore.kernel.org/r/20211111020738.2512932-7-seanjc@google.com --- arch/arm64/kernel/perf_callchain.c | 13 +++++++------ arch/arm64/kvm/perf.c | 35 ++++++++++++++------------------- arch/x86/events/core.c | 13 +++++++------ arch/x86/events/intel/core.c | 5 +---- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/pmu.c | 2 +- arch/x86/kvm/x86.c | 40 +++++++++++++++++++++----------------- arch/x86/xen/pmu.c | 32 +++++++++++++----------------- include/linux/perf_event.h | 10 ++++++---- 9 files changed, 73 insertions(+), 79 deletions(-) diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c index 86d9f2013172..274dc3e11b6d 100644 --- a/arch/arm64/kernel/perf_callchain.c +++ b/arch/arm64/kernel/perf_callchain.c @@ -104,7 +104,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, { struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - if (guest_cbs && guest_cbs->is_in_guest()) { + if (guest_cbs && guest_cbs->state()) { /* We don't support guest os callchain now */ return; } @@ -152,7 +152,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stackframe frame; - if (guest_cbs && guest_cbs->is_in_guest()) { + if (guest_cbs && guest_cbs->state()) { /* We don't support guest os callchain now */ return; } @@ -165,8 +165,8 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) { struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - if (guest_cbs && guest_cbs->is_in_guest()) - return guest_cbs->get_guest_ip(); + if (guest_cbs && guest_cbs->state()) + return guest_cbs->get_ip(); return instruction_pointer(regs); } @@ -174,10 +174,11 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) unsigned long perf_misc_flags(struct pt_regs *regs) { struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); + unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0; int misc = 0; - if (guest_cbs && guest_cbs->is_in_guest()) { - if (guest_cbs->is_user_mode()) + if (guest_state) { + if (guest_state & PERF_GUEST_USER) misc |= PERF_RECORD_MISC_GUEST_USER; else misc |= PERF_RECORD_MISC_GUEST_KERNEL; diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c index a0d660cf889e..dfa9bce8559e 100644 --- a/arch/arm64/kvm/perf.c +++ b/arch/arm64/kvm/perf.c @@ -13,39 +13,34 @@ DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available); -static int kvm_is_in_guest(void) +static unsigned int kvm_guest_state(void) { - return kvm_get_running_vcpu() != NULL; -} - -static int kvm_is_user_mode(void) -{ - struct kvm_vcpu *vcpu; + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); + unsigned int state; - vcpu = kvm_get_running_vcpu(); + if (!vcpu) + return 0; - if (vcpu) - return !vcpu_mode_priv(vcpu); + state = PERF_GUEST_ACTIVE; + if (!vcpu_mode_priv(vcpu)) + state |= PERF_GUEST_USER; - return 0; + return state; } static unsigned long kvm_get_guest_ip(void) { - struct kvm_vcpu *vcpu; - - vcpu = kvm_get_running_vcpu(); + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); - if (vcpu) - return *vcpu_pc(vcpu); + if (WARN_ON_ONCE(!vcpu)) + return 0; - return 0; + return *vcpu_pc(vcpu); } static struct perf_guest_info_callbacks kvm_guest_cbs = { - .is_in_guest = kvm_is_in_guest, - .is_user_mode = kvm_is_user_mode, - .get_guest_ip = kvm_get_guest_ip, + .state = kvm_guest_state, + .get_ip = kvm_get_guest_ip, }; void kvm_perf_init(void) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 32cec290d3ad..e29312a1003a 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2772,7 +2772,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re struct unwind_state state; unsigned long addr; - if (guest_cbs && guest_cbs->is_in_guest()) { + if (guest_cbs && guest_cbs->state()) { /* TODO: We don't support guest os callchain now */ return; } @@ -2876,7 +2876,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs struct stack_frame frame; const struct stack_frame __user *fp; - if (guest_cbs && guest_cbs->is_in_guest()) { + if (guest_cbs && guest_cbs->state()) { /* TODO: We don't support guest os callchain now */ return; } @@ -2955,8 +2955,8 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) { struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - if (guest_cbs && guest_cbs->is_in_guest()) - return guest_cbs->get_guest_ip(); + if (guest_cbs && guest_cbs->state()) + return guest_cbs->get_ip(); return regs->ip + code_segment_base(regs); } @@ -2964,10 +2964,11 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) unsigned long perf_misc_flags(struct pt_regs *regs) { struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); + unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0; int misc = 0; - if (guest_cbs && guest_cbs->is_in_guest()) { - if (guest_cbs->is_user_mode()) + if (guest_state) { + if (guest_state & PERF_GUEST_USER) misc |= PERF_RECORD_MISC_GUEST_USER; else misc |= PERF_RECORD_MISC_GUEST_KERNEL; diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 2258e02ca350..7ff24d1ecdb7 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2906,10 +2906,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) handled++; guest_cbs = perf_get_guest_cbs(); - if (unlikely(guest_cbs && guest_cbs->is_in_guest() && - guest_cbs->handle_intel_pt_intr)) - guest_cbs->handle_intel_pt_intr(); - else + if (likely(!guest_cbs || !guest_cbs->handle_intel_pt_intr())) intel_pt_interrupt(); } diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 41e858df5795..fa1b1a209945 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1895,7 +1895,7 @@ int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu); int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err); void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu); -int kvm_is_in_guest(void); +unsigned int kvm_guest_state(void); void __user *__x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size); diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 09873f6488f7..b2520b3e9e89 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -87,7 +87,7 @@ static void kvm_perf_overflow_intr(struct perf_event *perf_event, * woken up. So we should wake it, but this is impossible from * NMI context. Do it from irq work instead. */ - if (!kvm_is_in_guest()) + if (!kvm_guest_state()) irq_work_queue(&pmc_to_pmu(pmc)->irq_work); else kvm_make_request(KVM_REQ_PMI, pmc->vcpu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 760c4e3a8326..2011a1cfb42d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8472,44 +8472,48 @@ static void kvm_timer_init(void) DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu); EXPORT_PER_CPU_SYMBOL_GPL(current_vcpu); -int kvm_is_in_guest(void) +unsigned int kvm_guest_state(void) { - return __this_cpu_read(current_vcpu) != NULL; -} + struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + unsigned int state; -static int kvm_is_user_mode(void) -{ - int user_mode = 3; + if (!vcpu) + return 0; - if (__this_cpu_read(current_vcpu)) - user_mode = static_call(kvm_x86_get_cpl)(__this_cpu_read(current_vcpu)); + state = PERF_GUEST_ACTIVE; + if (static_call(kvm_x86_get_cpl)(vcpu)) + state |= PERF_GUEST_USER; - return user_mode != 0; + return state; } -static unsigned long kvm_get_guest_ip(void) +static unsigned long kvm_guest_get_ip(void) { - unsigned long ip = 0; + struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); - if (__this_cpu_read(current_vcpu)) - ip = kvm_rip_read(__this_cpu_read(current_vcpu)); + if (WARN_ON_ONCE(!vcpu)) + return 0; - return ip; + return kvm_rip_read(vcpu); } -static void kvm_handle_intel_pt_intr(void) +static unsigned int kvm_handle_intel_pt_intr(void) { struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + /* '0' on failure so that the !PT case can use a RET0 static call. */ + if (!vcpu) + return 0; + kvm_make_request(KVM_REQ_PMI, vcpu); __set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT, (unsigned long *)&vcpu->arch.pmu.global_status); + return 1; } static struct perf_guest_info_callbacks kvm_guest_cbs = { - .is_in_guest = kvm_is_in_guest, - .is_user_mode = kvm_is_user_mode, - .get_guest_ip = kvm_get_guest_ip, + .state = kvm_guest_state, + .get_ip = kvm_guest_get_ip, .handle_intel_pt_intr = NULL, }; diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c index e13b0b49fcdf..89dd6b1708b0 100644 --- a/arch/x86/xen/pmu.c +++ b/arch/x86/xen/pmu.c @@ -413,34 +413,29 @@ int pmu_apic_update(uint32_t val) } /* perf callbacks */ -static int xen_is_in_guest(void) +static unsigned int xen_guest_state(void) { const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + unsigned int state = 0; if (!xenpmu_data) { pr_warn_once("%s: pmudata not initialized\n", __func__); - return 0; + return state; } if (!xen_initial_domain() || (xenpmu_data->domain_id >= DOMID_SELF)) - return 0; + return state; - return 1; -} - -static int xen_is_user_mode(void) -{ - const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + state |= PERF_GUEST_ACTIVE; - if (!xenpmu_data) { - pr_warn_once("%s: pmudata not initialized\n", __func__); - return 0; + if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV) { + if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER) + state |= PERF_GUEST_USER; + } else if (xenpmu_data->pmu.r.regs.cpl & 3) { + state |= PERF_GUEST_USER; } - if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV) - return (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER); - else - return !!(xenpmu_data->pmu.r.regs.cpl & 3); + return state; } static unsigned long xen_get_guest_ip(void) @@ -456,9 +451,8 @@ static unsigned long xen_get_guest_ip(void) } static struct perf_guest_info_callbacks xen_guest_cbs = { - .is_in_guest = xen_is_in_guest, - .is_user_mode = xen_is_user_mode, - .get_guest_ip = xen_get_guest_ip, + .state = xen_guest_state, + .get_ip = xen_get_guest_ip, }; /* Convert registers from Xen's format to Linux' */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 98c204488496..5e6b346d62a7 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -26,11 +26,13 @@ # include #endif +#define PERF_GUEST_ACTIVE 0x01 +#define PERF_GUEST_USER 0x02 + struct perf_guest_info_callbacks { - int (*is_in_guest)(void); - int (*is_user_mode)(void); - unsigned long (*get_guest_ip)(void); - void (*handle_intel_pt_intr)(void); + unsigned int (*state)(void); + unsigned long (*get_ip)(void); + unsigned int (*handle_intel_pt_intr)(void); }; #ifdef CONFIG_HAVE_HW_BREAKPOINT -- cgit v1.2.3