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