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205 lines
5.1 KiB
205 lines
5.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright 2019 Arm Limited |
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* Author: Andrew Murray <[email protected]> |
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*/ |
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#include <linux/kvm_host.h> |
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#include <linux/perf_event.h> |
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#include <asm/kvm_hyp.h> |
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/* |
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* Given the perf event attributes and system type, determine |
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* if we are going to need to switch counters at guest entry/exit. |
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*/ |
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static bool kvm_pmu_switch_needed(struct perf_event_attr *attr) |
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{ |
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/** |
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* With VHE the guest kernel runs at EL1 and the host at EL2, |
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* where user (EL0) is excluded then we have no reason to switch |
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* counters. |
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*/ |
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if (has_vhe() && attr->exclude_user) |
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return false; |
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/* Only switch if attributes are different */ |
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return (attr->exclude_host != attr->exclude_guest); |
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} |
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/* |
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* Add events to track that we may want to switch at guest entry/exit |
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* time. |
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*/ |
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void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) |
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{ |
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struct kvm_host_data *ctx = this_cpu_ptr_hyp_sym(kvm_host_data); |
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if (!ctx || !kvm_pmu_switch_needed(attr)) |
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return; |
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if (!attr->exclude_host) |
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ctx->pmu_events.events_host |= set; |
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if (!attr->exclude_guest) |
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ctx->pmu_events.events_guest |= set; |
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} |
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/* |
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* Stop tracking events |
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*/ |
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void kvm_clr_pmu_events(u32 clr) |
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{ |
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struct kvm_host_data *ctx = this_cpu_ptr_hyp_sym(kvm_host_data); |
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if (!ctx) |
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return; |
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ctx->pmu_events.events_host &= ~clr; |
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ctx->pmu_events.events_guest &= ~clr; |
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} |
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#define PMEVTYPER_READ_CASE(idx) \ |
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case idx: \ |
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return read_sysreg(pmevtyper##idx##_el0) |
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#define PMEVTYPER_WRITE_CASE(idx) \ |
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case idx: \ |
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write_sysreg(val, pmevtyper##idx##_el0); \ |
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break |
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#define PMEVTYPER_CASES(readwrite) \ |
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PMEVTYPER_##readwrite##_CASE(0); \ |
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PMEVTYPER_##readwrite##_CASE(1); \ |
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PMEVTYPER_##readwrite##_CASE(2); \ |
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PMEVTYPER_##readwrite##_CASE(3); \ |
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PMEVTYPER_##readwrite##_CASE(4); \ |
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PMEVTYPER_##readwrite##_CASE(5); \ |
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PMEVTYPER_##readwrite##_CASE(6); \ |
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PMEVTYPER_##readwrite##_CASE(7); \ |
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PMEVTYPER_##readwrite##_CASE(8); \ |
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PMEVTYPER_##readwrite##_CASE(9); \ |
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PMEVTYPER_##readwrite##_CASE(10); \ |
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PMEVTYPER_##readwrite##_CASE(11); \ |
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PMEVTYPER_##readwrite##_CASE(12); \ |
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PMEVTYPER_##readwrite##_CASE(13); \ |
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PMEVTYPER_##readwrite##_CASE(14); \ |
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PMEVTYPER_##readwrite##_CASE(15); \ |
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PMEVTYPER_##readwrite##_CASE(16); \ |
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PMEVTYPER_##readwrite##_CASE(17); \ |
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PMEVTYPER_##readwrite##_CASE(18); \ |
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PMEVTYPER_##readwrite##_CASE(19); \ |
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PMEVTYPER_##readwrite##_CASE(20); \ |
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PMEVTYPER_##readwrite##_CASE(21); \ |
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PMEVTYPER_##readwrite##_CASE(22); \ |
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PMEVTYPER_##readwrite##_CASE(23); \ |
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PMEVTYPER_##readwrite##_CASE(24); \ |
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PMEVTYPER_##readwrite##_CASE(25); \ |
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PMEVTYPER_##readwrite##_CASE(26); \ |
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PMEVTYPER_##readwrite##_CASE(27); \ |
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PMEVTYPER_##readwrite##_CASE(28); \ |
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PMEVTYPER_##readwrite##_CASE(29); \ |
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PMEVTYPER_##readwrite##_CASE(30) |
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/* |
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* Read a value direct from PMEVTYPER<idx> where idx is 0-30 |
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* or PMCCFILTR_EL0 where idx is ARMV8_PMU_CYCLE_IDX (31). |
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*/ |
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static u64 kvm_vcpu_pmu_read_evtype_direct(int idx) |
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{ |
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switch (idx) { |
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PMEVTYPER_CASES(READ); |
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case ARMV8_PMU_CYCLE_IDX: |
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return read_sysreg(pmccfiltr_el0); |
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default: |
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WARN_ON(1); |
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} |
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return 0; |
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} |
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/* |
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* Write a value direct to PMEVTYPER<idx> where idx is 0-30 |
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* or PMCCFILTR_EL0 where idx is ARMV8_PMU_CYCLE_IDX (31). |
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*/ |
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static void kvm_vcpu_pmu_write_evtype_direct(int idx, u32 val) |
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{ |
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switch (idx) { |
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PMEVTYPER_CASES(WRITE); |
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case ARMV8_PMU_CYCLE_IDX: |
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write_sysreg(val, pmccfiltr_el0); |
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break; |
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default: |
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WARN_ON(1); |
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} |
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} |
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/* |
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* Modify ARMv8 PMU events to include EL0 counting |
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*/ |
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static void kvm_vcpu_pmu_enable_el0(unsigned long events) |
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{ |
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u64 typer; |
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u32 counter; |
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for_each_set_bit(counter, &events, 32) { |
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typer = kvm_vcpu_pmu_read_evtype_direct(counter); |
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typer &= ~ARMV8_PMU_EXCLUDE_EL0; |
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kvm_vcpu_pmu_write_evtype_direct(counter, typer); |
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} |
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} |
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/* |
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* Modify ARMv8 PMU events to exclude EL0 counting |
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*/ |
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static void kvm_vcpu_pmu_disable_el0(unsigned long events) |
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{ |
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u64 typer; |
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u32 counter; |
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for_each_set_bit(counter, &events, 32) { |
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typer = kvm_vcpu_pmu_read_evtype_direct(counter); |
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typer |= ARMV8_PMU_EXCLUDE_EL0; |
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kvm_vcpu_pmu_write_evtype_direct(counter, typer); |
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} |
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} |
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/* |
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* On VHE ensure that only guest events have EL0 counting enabled. |
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* This is called from both vcpu_{load,put} and the sysreg handling. |
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* Since the latter is preemptible, special care must be taken to |
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* disable preemption. |
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*/ |
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void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu) |
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{ |
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struct kvm_host_data *host; |
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u32 events_guest, events_host; |
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if (!has_vhe()) |
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return; |
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preempt_disable(); |
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host = this_cpu_ptr_hyp_sym(kvm_host_data); |
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events_guest = host->pmu_events.events_guest; |
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events_host = host->pmu_events.events_host; |
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kvm_vcpu_pmu_enable_el0(events_guest); |
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kvm_vcpu_pmu_disable_el0(events_host); |
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preempt_enable(); |
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} |
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/* |
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* On VHE ensure that only host events have EL0 counting enabled |
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*/ |
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void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) |
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{ |
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struct kvm_host_data *host; |
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u32 events_guest, events_host; |
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if (!has_vhe()) |
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return; |
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host = this_cpu_ptr_hyp_sym(kvm_host_data); |
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events_guest = host->pmu_events.events_guest; |
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events_host = host->pmu_events.events_host; |
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kvm_vcpu_pmu_enable_el0(events_host); |
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kvm_vcpu_pmu_disable_el0(events_guest); |
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}
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