vcpu_sbi_system.c

 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
12static 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		return kvm_riscv_vcpu_sbi_forward_handler(vcpu, run, retdata);
51	default:
52		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
53		break;
54	}
55
56	return 0;
57}
58
59const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_susp = {
60	.extid_start = SBI_EXT_SUSP,
61	.extid_end = SBI_EXT_SUSP,
62	.default_disabled = true,
63	.handler = kvm_sbi_ext_susp_handler,
64};