1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2023 Rivos Inc
4 *
5 * Authors:
6 *     Atish Patra <atishp@rivosinc.com>
7 */
8
9#include <linux/errno.h>
10#include <linux/err.h>
11#include <linux/kvm_host.h>
12#include <asm/csr.h>
13#include <asm/sbi.h>
14#include <asm/kvm_vcpu_sbi.h>
15
16static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
17				   struct kvm_vcpu_sbi_return *retdata)
18{
19	int ret = 0;
20	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
21	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
22	unsigned long funcid = cp->a6;
23	u64 temp;
24
25	if (!kvpmu->init_done) {
26		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
27		return 0;
28	}
29
30	switch (funcid) {
31	case SBI_EXT_PMU_NUM_COUNTERS:
32		ret = kvm_riscv_vcpu_pmu_num_ctrs(vcpu, retdata);
33		break;
34	case SBI_EXT_PMU_COUNTER_GET_INFO:
35		ret = kvm_riscv_vcpu_pmu_ctr_info(vcpu, cp->a0, retdata);
36		break;
37	case SBI_EXT_PMU_COUNTER_CFG_MATCH:
38#if defined(CONFIG_32BIT)
39		temp = ((uint64_t)cp->a5 << 32) | cp->a4;
40#else
41		temp = cp->a4;
42#endif
43		/*
44		 * This can fail if perf core framework fails to create an event.
45		 * Forward the error to userspace because it's an error which
46		 * happened within the host kernel. The other option would be
47		 * to convert to an SBI error and forward to the guest.
48		 */
49		ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1,
50						       cp->a2, cp->a3, temp, retdata);
51		break;
52	case SBI_EXT_PMU_COUNTER_START:
53#if defined(CONFIG_32BIT)
54		temp = ((uint64_t)cp->a4 << 32) | cp->a3;
55#else
56		temp = cp->a3;
57#endif
58		ret = kvm_riscv_vcpu_pmu_ctr_start(vcpu, cp->a0, cp->a1, cp->a2,
59						   temp, retdata);
60		break;
61	case SBI_EXT_PMU_COUNTER_STOP:
62		ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2, retdata);
63		break;
64	case SBI_EXT_PMU_COUNTER_FW_READ:
65		ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, retdata);
66		break;
67	default:
68		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
69	}
70
71	return ret;
72}
73
74static unsigned long kvm_sbi_ext_pmu_probe(struct kvm_vcpu *vcpu)
75{
76	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
77
78	return kvpmu->init_done;
79}
80
81const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
82	.extid_start = SBI_EXT_PMU,
83	.extid_end = SBI_EXT_PMU,
84	.handler = kvm_sbi_ext_pmu_handler,
85	.probe = kvm_sbi_ext_pmu_probe,
86};
87