9589a38cdf
The host currently writes directly in EL2 per-CPU data sections from the PMU code when running in nVHE. In preparation for unmapping the EL2 sections from the host stage 2, disable PMU support in protected mode as we currently do not have a use-case for it. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-38-qperret@google.com
69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Based on the x86 implementation.
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*/
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#include <linux/perf_event.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_emulate.h>
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DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
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static int kvm_is_in_guest(void)
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{
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return kvm_get_running_vcpu() != NULL;
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}
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static int kvm_is_user_mode(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return !vcpu_mode_priv(vcpu);
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return 0;
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}
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static unsigned long kvm_get_guest_ip(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return *vcpu_pc(vcpu);
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return 0;
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}
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static struct perf_guest_info_callbacks kvm_guest_cbs = {
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.is_in_guest = kvm_is_in_guest,
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.is_user_mode = kvm_is_user_mode,
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.get_guest_ip = kvm_get_guest_ip,
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};
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int kvm_perf_init(void)
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{
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/*
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* Check if HW_PERF_EVENTS are supported by checking the number of
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* hardware performance counters. This could ensure the presence of
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* a physical PMU and CONFIG_PERF_EVENT is selected.
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*/
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if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0
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&& !is_protected_kvm_enabled())
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static_branch_enable(&kvm_arm_pmu_available);
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return perf_register_guest_info_callbacks(&kvm_guest_cbs);
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}
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int kvm_perf_teardown(void)
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{
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return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
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}
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