linux/arch/riscv/kvm/vcpu_sbi_pmu.c
Atish Patra cbddc4c4cb RISC-V: KVM: Add SBI PMU extension support
SBI PMU extension allows KVM guests to configure/start/stop/query
about the PMU counters in virtualized enviornment as well.

In order to allow that, KVM implements the entire SBI PMU extension.

Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07 20:35:53 +05:30

87 lines
2.2 KiB
C

// 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.
* Forward the error to userspace because it's an error which
* happened within the host kernel. The other option would be
* to convert to an SBI error and forward 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_ctr_read(vcpu, cp->a0, 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;
}
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
.extid_start = SBI_EXT_PMU,
.extid_end = SBI_EXT_PMU,
.handler = kvm_sbi_ext_pmu_handler,
.probe = kvm_sbi_ext_pmu_probe,
};