This patch only adds barebone structure of perf implementation. Most of the function returns zero at this point and will be implemented fully in the future. Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> --- arch/riscv/include/asm/kvm_host.h | 4 + arch/riscv/include/asm/kvm_vcpu_pmu.h | 78 +++++++++++++++ arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu.c | 7 ++ arch/riscv/kvm/vcpu_pmu.c | 136 ++++++++++++++++++++++++++ 5 files changed, 226 insertions(+) create mode 100644 arch/riscv/include/asm/kvm_vcpu_pmu.h create mode 100644 arch/riscv/kvm/vcpu_pmu.c diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 93f43a3..b90be9a 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -18,6 +18,7 @@ #include <asm/kvm_vcpu_insn.h> #include <asm/kvm_vcpu_sbi.h> #include <asm/kvm_vcpu_timer.h> +#include <asm/kvm_vcpu_pmu.h> #define KVM_MAX_VCPUS 1024 @@ -228,6 +229,9 @@ struct kvm_vcpu_arch { /* Don't run the VCPU (blocked) */ bool pause; + + /* Performance monitoring context */ + struct kvm_pmu pmu_context; }; static inline void kvm_arch_hardware_unsetup(void) {} diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h new file mode 100644 index 0000000..e2b4038 --- /dev/null +++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2023 Rivos Inc + * + * Authors: + * Atish Patra <atishp@xxxxxxxxxxxx> + */ + +#ifndef __KVM_VCPU_RISCV_PMU_H +#define __KVM_VCPU_RISCV_PMU_H + +#include <linux/perf/riscv_pmu.h> +#include <asm/kvm_vcpu_sbi.h> +#include <asm/sbi.h> + +#ifdef CONFIG_RISCV_PMU_SBI +#define RISCV_KVM_MAX_FW_CTRS 32 + +#if RISCV_KVM_MAX_FW_CTRS > 32 +#error "Maximum firmware counter can't exceed 32 without increasing the RISCV_MAX_COUNTERS" +#endif + +#define RISCV_MAX_COUNTERS 64 + +/* Per virtual pmu counter data */ +struct kvm_pmc { + u8 idx; + struct perf_event *perf_event; + uint64_t counter_val; + union sbi_pmu_ctr_info cinfo; + /* Event monitoring status */ + bool started; +}; + +/* PMU data structure per vcpu */ +struct kvm_pmu { + struct kvm_pmc pmc[RISCV_MAX_COUNTERS]; + /* Number of the virtual firmware counters available */ + int num_fw_ctrs; + /* Number of the virtual hardware counters available */ + int num_hw_ctrs; + /* A flag to indicate that pmu initialization is done */ + bool init_done; + /* Bit map of all the virtual counter used */ + DECLARE_BITMAP(pmc_in_use, RISCV_MAX_COUNTERS); +}; + +#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu_context) +#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu_context)) + +int kvm_riscv_vcpu_pmu_num_ctrs(struct kvm_vcpu *vcpu, struct kvm_vcpu_sbi_return *retdata); +int kvm_riscv_vcpu_pmu_ctr_info(struct kvm_vcpu *vcpu, unsigned long cidx, + struct kvm_vcpu_sbi_return *retdata); +int kvm_riscv_vcpu_pmu_ctr_start(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, uint64_t ival, + struct kvm_vcpu_sbi_return *retdata); +int kvm_riscv_vcpu_pmu_ctr_stop(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, + struct kvm_vcpu_sbi_return *retdata); +int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, + unsigned long eidx, uint64_t evtdata, + struct kvm_vcpu_sbi_return *retdata); +int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, + struct kvm_vcpu_sbi_return *retdata); +void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu); +void kvm_riscv_vcpu_pmu_deinit(struct kvm_vcpu *vcpu); +void kvm_riscv_vcpu_pmu_reset(struct kvm_vcpu *vcpu); + +#else +struct kvm_pmu { +}; + +static inline void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) {} +static inline void kvm_riscv_vcpu_pmu_deinit(struct kvm_vcpu *vcpu) {} +static inline void kvm_riscv_vcpu_pmu_reset(struct kvm_vcpu *vcpu) {} +#endif /* CONFIG_RISCV_PMU_SBI */ +#endif /* !__KVM_VCPU_RISCV_PMU_H */ diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 019df920..5de1053 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -25,3 +25,4 @@ kvm-y += vcpu_sbi_base.o kvm-y += vcpu_sbi_replace.o kvm-y += vcpu_sbi_hsm.o kvm-y += vcpu_timer.o +kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 7c08567..7d010b0 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -138,6 +138,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) WRITE_ONCE(vcpu->arch.irqs_pending, 0); WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0); + kvm_riscv_vcpu_pmu_reset(vcpu); + vcpu->arch.hfence_head = 0; vcpu->arch.hfence_tail = 0; memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue)); @@ -194,6 +196,9 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) /* Setup VCPU timer */ kvm_riscv_vcpu_timer_init(vcpu); + /* setup performance monitoring */ + kvm_riscv_vcpu_pmu_init(vcpu); + /* Reset VCPU */ kvm_riscv_reset_vcpu(vcpu); @@ -216,6 +221,8 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) /* Cleanup VCPU timer */ kvm_riscv_vcpu_timer_deinit(vcpu); + kvm_riscv_vcpu_pmu_deinit(vcpu); + /* Free unused pages pre-allocated for G-stage page table mappings */ kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); } diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c new file mode 100644 index 0000000..2dad37f --- /dev/null +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2023 Rivos Inc + * + * Authors: + * Atish Patra <atishp@xxxxxxxxxxxx> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <linux/perf/riscv_pmu.h> +#include <asm/csr.h> +#include <asm/kvm_vcpu_sbi.h> +#include <asm/kvm_vcpu_pmu.h> +#include <linux/kvm_host.h> + +#define kvm_pmu_num_counters(pmu) ((pmu)->num_hw_ctrs + (pmu)->num_fw_ctrs) + +int kvm_riscv_vcpu_pmu_num_ctrs(struct kvm_vcpu *vcpu, struct kvm_vcpu_sbi_return *retdata) +{ + struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); + + retdata->out_val = kvm_pmu_num_counters(kvpmu); + + return 0; +} + +int kvm_riscv_vcpu_pmu_ctr_info(struct kvm_vcpu *vcpu, unsigned long cidx, + struct kvm_vcpu_sbi_return *retdata) +{ + struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); + + if (cidx > RISCV_MAX_COUNTERS || cidx == 1) { + retdata->err_val = SBI_ERR_INVALID_PARAM; + return 0; + } + + retdata->out_val = kvpmu->pmc[cidx].cinfo.value; + + return 0; +} + +int kvm_riscv_vcpu_pmu_ctr_start(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, uint64_t ival, + struct kvm_vcpu_sbi_return *retdata) +{ + /* TODO */ + return 0; +} + +int kvm_riscv_vcpu_pmu_ctr_stop(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, + struct kvm_vcpu_sbi_return *retdata) +{ + /* TODO */ + return 0; +} + +int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_base, + unsigned long ctr_mask, unsigned long flag, + unsigned long eidx, uint64_t evtdata, + struct kvm_vcpu_sbi_return *retdata) +{ + /* TODO */ + return 0; +} + +int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, + struct kvm_vcpu_sbi_return *retdata) +{ + /* TODO */ + return 0; +} + +void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) +{ + int i = 0, ret, num_hw_ctrs = 0, hpm_width = 0; + struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + + ret = riscv_pmu_get_hpm_info(&hpm_width, &num_hw_ctrs); + if (ret < 0 || !hpm_width || !num_hw_ctrs) + return; + + /* + * It is guranteed that RISCV_KVM_MAX_FW_CTRS can't exceed 32 as + * that may exceed total number of counters more than RISCV_MAX_COUNTERS + */ + kvpmu->num_hw_ctrs = num_hw_ctrs; + kvpmu->num_fw_ctrs = RISCV_KVM_MAX_FW_CTRS; + + /* + * There is no correlation between the logical hardware counter and virtual counters. + * However, we need to encode a hpmcounter CSR in the counter info field so that + * KVM can trap n emulate the read. This works well in the migration use case as + * KVM doesn't care if the actual hpmcounter is available in the hardware or not. + */ + for (i = 0; i < kvm_pmu_num_counters(kvpmu); i++) { + /* TIME CSR shouldn't be read from perf interface */ + if (i == 1) + continue; + pmc = &kvpmu->pmc[i]; + pmc->idx = i; + if (i < kvpmu->num_hw_ctrs) { + pmc->cinfo.type = SBI_PMU_CTR_TYPE_HW; + if (i < 3) + /* CY, IR counters */ + pmc->cinfo.width = 63; + else + pmc->cinfo.width = hpm_width; + /* + * The CSR number doesn't have any relation with the logical + * hardware counters. The CSR numbers are encoded sequentially + * to avoid maintaining a map between the virtual counter + * and CSR number. + */ + pmc->cinfo.csr = CSR_CYCLE + i; + } else { + pmc->cinfo.type = SBI_PMU_CTR_TYPE_FW; + pmc->cinfo.width = BITS_PER_LONG - 1; + } + } + + kvpmu->init_done = true; +} + +void kvm_riscv_vcpu_pmu_deinit(struct kvm_vcpu *vcpu) +{ + /* TODO */ +} + +void kvm_riscv_vcpu_pmu_reset(struct kvm_vcpu *vcpu) +{ + kvm_riscv_vcpu_pmu_deinit(vcpu); +} -- 2.25.1