arch/riscv/kvm/vcpu_sbi_pmu.c

Source file repositories/reference/linux-study-clean/arch/riscv/kvm/vcpu_sbi_pmu.c

File Facts

System
Linux kernel
Corpus path
arch/riscv/kvm/vcpu_sbi_pmu.c
Extension
.c
Size
2672 bytes
Lines
99
Domain
Architecture Layer
Bucket
arch/riscv
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2023 Rivos Inc
 *
 * Authors:
 *     Atish Patra <atishp@rivosinc.com>
 */

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <asm/csr.h>
#include <asm/sbi.h>
#include <asm/kvm_vcpu_sbi.h>

static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
				   struct kvm_vcpu_sbi_return *retdata)
{
	int ret = 0;
	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
	unsigned long funcid = cp->a6;
	u64 temp;

	if (!kvpmu->init_done) {
		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
		return 0;
	}

	switch (funcid) {
	case SBI_EXT_PMU_NUM_COUNTERS:
		ret = kvm_riscv_vcpu_pmu_num_ctrs(vcpu, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_GET_INFO:
		ret = kvm_riscv_vcpu_pmu_ctr_info(vcpu, cp->a0, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_CFG_MATCH:
#if defined(CONFIG_32BIT)
		temp = ((uint64_t)cp->a5 << 32) | cp->a4;
#else
		temp = cp->a4;
#endif
		/*
		 * This can fail if perf core framework fails to create an event.
		 * No need to forward the error to userspace and exit the guest.
		 * The operation can continue without profiling. Forward the
		 * appropriate SBI error to the guest.
		 */
		ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1,
						       cp->a2, cp->a3, temp, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_START:
#if defined(CONFIG_32BIT)
		temp = ((uint64_t)cp->a4 << 32) | cp->a3;
#else
		temp = cp->a3;
#endif
		ret = kvm_riscv_vcpu_pmu_ctr_start(vcpu, cp->a0, cp->a1, cp->a2,
						   temp, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_STOP:
		ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_FW_READ:
		ret = kvm_riscv_vcpu_pmu_fw_ctr_read(vcpu, cp->a0, retdata);
		break;
	case SBI_EXT_PMU_COUNTER_FW_READ_HI:
		if (IS_ENABLED(CONFIG_32BIT))
			ret = kvm_riscv_vcpu_pmu_fw_ctr_read_hi(vcpu, cp->a0, retdata);
		else
			retdata->out_val = 0;
		break;
	case SBI_EXT_PMU_SNAPSHOT_SET_SHMEM:
		ret = kvm_riscv_vcpu_pmu_snapshot_set_shmem(vcpu, cp->a0, cp->a1, cp->a2, retdata);
		break;
	case SBI_EXT_PMU_EVENT_GET_INFO:
		ret = kvm_riscv_vcpu_pmu_event_info(vcpu, cp->a0, cp->a1, cp->a2, cp->a3, retdata);
		break;
	default:
		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
	}

	return ret;
}

static unsigned long kvm_sbi_ext_pmu_probe(struct kvm_vcpu *vcpu)
{
	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);

	return kvpmu->init_done;

Annotation

Implementation Notes