vcpu_sbi_pmu.c

 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		 * No need to forward the error to userspace and exit the guest.
46		 * The operation can continue without profiling. Forward the
47		 * appropriate SBI error 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_fw_ctr_read(vcpu, cp->a0, retdata);
66		break;
67	case SBI_EXT_PMU_COUNTER_FW_READ_HI:
68		if (IS_ENABLED(CONFIG_32BIT))
69			ret = kvm_riscv_vcpu_pmu_fw_ctr_read_hi(vcpu, cp->a0, retdata);
70		else
71			retdata->out_val = 0;
72		break;
73	case SBI_EXT_PMU_SNAPSHOT_SET_SHMEM:
74		ret = kvm_riscv_vcpu_pmu_snapshot_set_shmem(vcpu, cp->a0, cp->a1, cp->a2, retdata);
75		break;
76	case SBI_EXT_PMU_EVENT_GET_INFO:
77		ret = kvm_riscv_vcpu_pmu_event_info(vcpu, cp->a0, cp->a1, cp->a2, cp->a3, retdata);
78		break;
79	default:
80		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
81	}
82
83	return ret;
84}
85
86static unsigned long kvm_sbi_ext_pmu_probe(struct kvm_vcpu *vcpu)
87{
88	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
89
90	return kvpmu->init_done;
91}
92
93const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
94	.extid_start = SBI_EXT_PMU,
95	.extid_end = SBI_EXT_PMU,
96	.handler = kvm_sbi_ext_pmu_handler,
97	.probe = kvm_sbi_ext_pmu_probe,
98};