1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2021 Western Digital Corporation or its affiliates.
4 *
5 * Authors:
6 *     Atish Patra <atish.patra@wdc.com>
7 */
8
9#include <linux/errno.h>
10#include <linux/err.h>
11#include <linux/kvm_host.h>
12#include <linux/version.h>
13#include <asm/sbi.h>
14#include <asm/kvm_vcpu_sbi.h>
15
16static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
17				    struct kvm_vcpu_sbi_return *retdata)
18{
19	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
20	const struct kvm_vcpu_sbi_extension *sbi_ext;
21	unsigned long *out_val = &retdata->out_val;
22
23	switch (cp->a6) {
24	case SBI_EXT_BASE_GET_SPEC_VERSION:
25		*out_val = (KVM_SBI_VERSION_MAJOR <<
26			    SBI_SPEC_VERSION_MAJOR_SHIFT) |
27			    KVM_SBI_VERSION_MINOR;
28		break;
29	case SBI_EXT_BASE_GET_IMP_ID:
30		*out_val = KVM_SBI_IMPID;
31		break;
32	case SBI_EXT_BASE_GET_IMP_VERSION:
33		*out_val = LINUX_VERSION_CODE;
34		break;
35	case SBI_EXT_BASE_PROBE_EXT:
36		if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
37		     cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
38		    (cp->a0 >= SBI_EXT_VENDOR_START &&
39		     cp->a0 <= SBI_EXT_VENDOR_END)) {
40			/*
41			 * For experimental/vendor extensions
42			 * forward it to the userspace
43			 */
44			kvm_riscv_vcpu_sbi_forward(vcpu, run);
45			retdata->uexit = true;
46		} else {
47			sbi_ext = kvm_vcpu_sbi_find_ext(vcpu, cp->a0);
48			*out_val = sbi_ext && sbi_ext->probe ?
49					   sbi_ext->probe(vcpu) : !!sbi_ext;
50		}
51		break;
52	case SBI_EXT_BASE_GET_MVENDORID:
53		*out_val = vcpu->arch.mvendorid;
54		break;
55	case SBI_EXT_BASE_GET_MARCHID:
56		*out_val = vcpu->arch.marchid;
57		break;
58	case SBI_EXT_BASE_GET_MIMPID:
59		*out_val = vcpu->arch.mimpid;
60		break;
61	default:
62		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
63		break;
64	}
65
66	return 0;
67}
68
69const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = {
70	.extid_start = SBI_EXT_BASE,
71	.extid_end = SBI_EXT_BASE,
72	.handler = kvm_sbi_ext_base_handler,
73};
74
75static int kvm_sbi_ext_forward_handler(struct kvm_vcpu *vcpu,
76				       struct kvm_run *run,
77				       struct kvm_vcpu_sbi_return *retdata)
78{
79	/*
80	 * Both SBI experimental and vendor extensions are
81	 * unconditionally forwarded to userspace.
82	 */
83	kvm_riscv_vcpu_sbi_forward(vcpu, run);
84	retdata->uexit = true;
85	return 0;
86}
87
88const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental = {
89	.extid_start = SBI_EXT_EXPERIMENTAL_START,
90	.extid_end = SBI_EXT_EXPERIMENTAL_END,
91	.handler = kvm_sbi_ext_forward_handler,
92};
93
94const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor = {
95	.extid_start = SBI_EXT_VENDOR_START,
96	.extid_end = SBI_EXT_VENDOR_END,
97	.handler = kvm_sbi_ext_forward_handler,
98};
99