[PATCH v3 06/16] perf/core: Rework guest callbacks to prepare for static_call support
From: Sean Christopherson <seanjc@google.com>
Date: 2021-09-22 00:06:11
Also in:
kvm, kvmarm, linux-perf-users, linux-riscv, lkml, xen-devel
Subsystem:
arm pmu profiling and debugging, arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), kernel virtual machine for x86 (kvm/x86), performance events subsystem, the rest, x86 architecture (32-bit and 64-bit), xen hypervisor x86 · Maintainers:
Will Deacon, Mark Rutland, Catalin Marinas, Marc Zyngier, Oliver Upton, Sean Christopherson, Paolo Bonzini, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen, Juergen Gross
From: Like Xu <redacted> 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 ->is_in_guest. 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. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Originally-by: Peter Zijlstra (Intel) [off-list ref] Signed-off-by: Like Xu <redacted> Signed-off-by: Zhu Lingshan <redacted> [sean: extracted from static_call patch, fixed get_ip() bug, wrote changelog] Signed-off-by: Sean Christopherson <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 +++++--- kernel/events/core.c | 1 + 10 files changed, 74 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 c37c0cf1bfe9..3e99ac4ab2d6 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; -} + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); + unsigned int state; -static int kvm_is_user_mode(void) -{ - struct kvm_vcpu *vcpu; - - 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; + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); - vcpu = kvm_get_running_vcpu(); + if (WARN_ON_ONCE(!vcpu)) + return 0; - if (vcpu) - return *vcpu_pc(vcpu); - - 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 ffb3e6c0d367..3a7630fdd340 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c@@ -2765,7 +2765,7 @@ 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; }
@@ -2869,7 +2869,7 @@ 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; }
@@ -2948,8 +2948,8 @@ 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); }
@@ -2957,10 +2957,11 @@ 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 9baa46185d94..524ad1f747bd 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c@@ -2855,10 +2855,7 @@ 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 1ea4943a73d7..1080166fc0cf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -1874,7 +1874,7 @@ 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 0772bad9165c..5b68d4188de0 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 ffc6c2d73508..6cc66466f301 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -8267,44 +8267,48 @@ 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; -} + state |= PERF_GUEST_ACTIVE; -static int xen_is_user_mode(void) -{ - const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); - - 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 317d4658afe9..f9be88a47434 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h@@ -26,11 +26,13 @@ # include <asm/local64.h> #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
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d90a43572400..2e3dc9fbd5d9 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c@@ -6483,6 +6483,7 @@ static void perf_pending_event(struct irq_work *entry) } struct perf_guest_info_callbacks *perf_guest_cbs; + void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) { if (WARN_ON_ONCE(perf_guest_cbs))
--
2.33.0.464.g1972c5931b-goog
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