From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933776AbcIEQc6 (ORCPT ); Mon, 5 Sep 2016 12:32:58 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.140]:28901 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933578AbcIEQcw (ORCPT ); Mon, 5 Sep 2016 12:32:52 -0400 From: Punit Agrawal To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Cc: Punit Agrawal , Christoffer Dall , Marc Zyngier , Steven Rostedt , Ingo Molnar , Will Deacon Subject: [RFC v2 PATCH 3/7] KVM: arm/arm64: Register perf trace event notifier Date: Mon, 5 Sep 2016 17:31:33 +0100 Message-Id: <1473093097-30932-4-git-send-email-punit.agrawal@arm.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1473093097-30932-1-git-send-email-punit.agrawal@arm.com> References: <1473093097-30932-1-git-send-email-punit.agrawal@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Register a notifier to track state changes of perf trace events. The notifier will enable taking appropriate action for trace events targeting VM. Signed-off-by: Punit Agrawal Cc: Christoffer Dall Cc: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 3 + arch/arm/kvm/arm.c | 2 + arch/arm64/include/asm/kvm_host.h | 8 +++ arch/arm64/kvm/Kconfig | 4 ++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/perf_trace.c | 122 ++++++++++++++++++++++++++++++++++++++ 6 files changed, 140 insertions(+) create mode 100644 arch/arm64/kvm/perf_trace.c diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index de338d9..609998e 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -280,6 +280,9 @@ static inline int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext) int kvm_perf_init(void); int kvm_perf_teardown(void); +static inline int kvm_perf_trace_init(void) { return 0; } +static inline int kvm_perf_trace_teardown(void) { return 0; } + void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 75f130e..e1b99c4 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -1220,6 +1220,7 @@ static int init_subsystems(void) goto out; kvm_perf_init(); + kvm_perf_trace_init(); kvm_coproc_table_init(); out: @@ -1411,6 +1412,7 @@ out_err: void kvm_arch_exit(void) { kvm_perf_teardown(); + kvm_perf_trace_teardown(); } static int arm_init(void) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 3eda975..f6ff8e5 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -345,6 +345,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, int kvm_perf_init(void); int kvm_perf_teardown(void); +#if !defined(CONFIG_KVM_PERF_TRACE) +static inline int kvm_perf_trace_init(void) { return 0; } +static inline int kvm_perf_trace_teardown(void) { return 0; } +#else +int kvm_perf_trace_init(void); +int kvm_perf_trace_teardown(void); +#endif + struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 9c9edc9..56e9537 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -19,6 +19,9 @@ if VIRTUALIZATION config KVM_ARM_VGIC_V3 bool +config KVM_PERF_TRACE + bool + config KVM bool "Kernel-based Virtual Machine (KVM) support" depends on OF @@ -39,6 +42,7 @@ config KVM select HAVE_KVM_MSI select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQ_ROUTING + select KVM_PERF_TRACE if EVENT_TRACING && PERF_EVENTS ---help--- Support hosting virtualized guest machines. We don't support KVM with 16K page tables yet, due to the multiple diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 695eb3c..7d175e4 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -19,6 +19,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o kvm-$(CONFIG_KVM_ARM_HOST) += emulate.o inject_fault.o regmap.o kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o kvm-$(CONFIG_KVM_ARM_HOST) += guest.o debug.o reset.o sys_regs.o sys_regs_generic_v8.o +kvm-$(CONFIG_KVM_PERF_TRACE) += perf_trace.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o diff --git a/arch/arm64/kvm/perf_trace.c b/arch/arm64/kvm/perf_trace.c new file mode 100644 index 0000000..8bacd18 --- /dev/null +++ b/arch/arm64/kvm/perf_trace.c @@ -0,0 +1,122 @@ +/* + * Copyright (C) 2016 ARM Ltd. + * Author: Punit Agrawal + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include +#include + +typedef int (*perf_trace_callback_fn)(struct kvm *kvm, bool enable); + +struct kvm_trace_hook { + char *key; + perf_trace_callback_fn setup_fn; +}; + +static struct kvm_trace_hook trace_hook[] = { + { }, +}; + +static perf_trace_callback_fn find_trace_callback(const char *trace_key) +{ + int i; + + for (i = 0; trace_hook[i].key; i++) + if (!strcmp(trace_key, trace_hook[i].key)) + return trace_hook[i].setup_fn; + + return NULL; +} + +static int kvm_perf_trace_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct perf_event *p_event = data; + struct trace_event_call *tp_event = p_event->tp_event; + perf_trace_callback_fn setup_trace_fn; + struct kvm *kvm = NULL; + struct pid *pid; + bool found = false; + + /* + * Is this a trace point? + */ + if (!(tp_event->flags & TRACE_EVENT_FL_TRACEPOINT)) + goto out; + + /* + * We'll get here for events we care to monitor for KVM. As we + * only care about events attached to a VM, check that there + * is a task associated with the perf event. + */ + if (p_event->attach_state != PERF_ATTACH_TASK) + goto out; + + /* + * This notifier gets called when perf trace event instance is + * added or removed. Until we can restrict this to events of + * interest in core, minimise the overhead below. + * + * Do we care about it? i.e., is there a callback for this + * trace point? + */ + setup_trace_fn = find_trace_callback(tp_event->tp->name); + if (!setup_trace_fn) + goto out; + + pid = get_task_pid(p_event->hw.target, PIDTYPE_PID); + + /* + * Does it match any of the VMs? + */ + spin_lock(&kvm_lock); + list_for_each_entry(kvm, &vm_list, vm_list) { + if (kvm->pid == pid) { + found = true; + break; + } + } + spin_unlock(&kvm_lock); + + put_pid(pid); + if (!found) + goto out; + + switch (event) { + case TRACE_REG_PERF_OPEN: + setup_trace_fn(kvm, true); + break; + + case TRACE_REG_PERF_CLOSE: + setup_trace_fn(kvm, false); + break; + } + +out: + return 0; +} + +static struct notifier_block kvm_perf_trace_notifier_block = { + .notifier_call = kvm_perf_trace_notifier, +}; + +int kvm_perf_trace_init(void) +{ + return perf_trace_notifier_register(&kvm_perf_trace_notifier_block); +} + +int kvm_perf_trace_teardown(void) +{ + return perf_trace_notifier_unregister(&kvm_perf_trace_notifier_block); +} -- 2.8.1