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/csr.h>
14 #include <asm/sbi.h>
15 #include <asm/kvm_vcpu_timer.h>
16 #include <asm/kvm_vcpu_sbi.h>
17
kvm_sbi_ext_base_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,unsigned long * out_val,struct kvm_cpu_trap * trap,bool * exit)18 static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
19 unsigned long *out_val,
20 struct kvm_cpu_trap *trap, bool *exit)
21 {
22 int ret = 0;
23 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
24 struct sbiret ecall_ret;
25
26 switch (cp->a6) {
27 case SBI_EXT_BASE_GET_SPEC_VERSION:
28 *out_val = (KVM_SBI_VERSION_MAJOR <<
29 SBI_SPEC_VERSION_MAJOR_SHIFT) |
30 KVM_SBI_VERSION_MINOR;
31 break;
32 case SBI_EXT_BASE_GET_IMP_ID:
33 *out_val = KVM_SBI_IMPID;
34 break;
35 case SBI_EXT_BASE_GET_IMP_VERSION:
36 *out_val = LINUX_VERSION_CODE;
37 break;
38 case SBI_EXT_BASE_PROBE_EXT:
39 if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
40 cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
41 (cp->a0 >= SBI_EXT_VENDOR_START &&
42 cp->a0 <= SBI_EXT_VENDOR_END)) {
43 /*
44 * For experimental/vendor extensions
45 * forward it to the userspace
46 */
47 kvm_riscv_vcpu_sbi_forward(vcpu, run);
48 *exit = true;
49 } else
50 *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0;
51 break;
52 case SBI_EXT_BASE_GET_MVENDORID:
53 case SBI_EXT_BASE_GET_MARCHID:
54 case SBI_EXT_BASE_GET_MIMPID:
55 ecall_ret = sbi_ecall(SBI_EXT_BASE, cp->a6, 0, 0, 0, 0, 0, 0);
56 if (!ecall_ret.error)
57 *out_val = ecall_ret.value;
58 /*TODO: We are unnecessarily converting the error twice */
59 ret = sbi_err_map_linux_errno(ecall_ret.error);
60 break;
61 default:
62 ret = -EOPNOTSUPP;
63 break;
64 }
65
66 return ret;
67 }
68
69 const 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
kvm_sbi_ext_forward_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,unsigned long * out_val,struct kvm_cpu_trap * utrap,bool * exit)75 static int kvm_sbi_ext_forward_handler(struct kvm_vcpu *vcpu,
76 struct kvm_run *run,
77 unsigned long *out_val,
78 struct kvm_cpu_trap *utrap,
79 bool *exit)
80 {
81 /*
82 * Both SBI experimental and vendor extensions are
83 * unconditionally forwarded to userspace.
84 */
85 kvm_riscv_vcpu_sbi_forward(vcpu, run);
86 *exit = true;
87 return 0;
88 }
89
90 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental = {
91 .extid_start = SBI_EXT_EXPERIMENTAL_START,
92 .extid_end = SBI_EXT_EXPERIMENTAL_END,
93 .handler = kvm_sbi_ext_forward_handler,
94 };
95
96 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor = {
97 .extid_start = SBI_EXT_VENDOR_START,
98 .extid_end = SBI_EXT_VENDOR_END,
99 .handler = kvm_sbi_ext_forward_handler,
100 };
101