1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2024 Ventana Micro Systems Inc.
4 */
5
6 #include <linux/kvm_host.h>
7 #include <linux/wordpart.h>
8
9 #include <asm/kvm_vcpu_sbi.h>
10 #include <asm/sbi.h>
11
kvm_sbi_ext_susp_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,struct kvm_vcpu_sbi_return * retdata)12 static int kvm_sbi_ext_susp_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
13 struct kvm_vcpu_sbi_return *retdata)
14 {
15 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
16 unsigned long funcid = cp->a6;
17 unsigned long hva, i;
18 struct kvm_vcpu *tmp;
19
20 switch (funcid) {
21 case SBI_EXT_SUSP_SYSTEM_SUSPEND:
22 if (lower_32_bits(cp->a0) != SBI_SUSP_SLEEP_TYPE_SUSPEND_TO_RAM) {
23 retdata->err_val = SBI_ERR_INVALID_PARAM;
24 return 0;
25 }
26
27 if (!(cp->sstatus & SR_SPP)) {
28 retdata->err_val = SBI_ERR_FAILURE;
29 return 0;
30 }
31
32 hva = kvm_vcpu_gfn_to_hva_prot(vcpu, cp->a1 >> PAGE_SHIFT, NULL);
33 if (kvm_is_error_hva(hva)) {
34 retdata->err_val = SBI_ERR_INVALID_ADDRESS;
35 return 0;
36 }
37
38 kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
39 if (tmp == vcpu)
40 continue;
41 if (!kvm_riscv_vcpu_stopped(tmp)) {
42 retdata->err_val = SBI_ERR_DENIED;
43 return 0;
44 }
45 }
46
47 kvm_riscv_vcpu_sbi_request_reset(vcpu, cp->a1, cp->a2);
48
49 /* userspace provides the suspend implementation */
50 kvm_riscv_vcpu_sbi_forward(vcpu, run);
51 retdata->uexit = true;
52 break;
53 default:
54 retdata->err_val = SBI_ERR_NOT_SUPPORTED;
55 break;
56 }
57
58 return 0;
59 }
60
61 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_susp = {
62 .extid_start = SBI_EXT_SUSP,
63 .extid_end = SBI_EXT_SUSP,
64 .default_disabled = true,
65 .handler = kvm_sbi_ext_susp_handler,
66 };
67