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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
4 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
5 */
6
7#include <linux/kvm.h>
8#include <linux/kvm_host.h>
9#include <asm/kvm_emulate.h>
10#include <asm/kvm_coproc.h>
11#include <asm/kvm_mmu.h>
12#include <kvm/arm_psci.h>
13#include <trace/events/kvm.h>
14
15#include "trace.h"
16
17typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
18
19static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
20{
21 int ret;
22
23 trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
24 kvm_vcpu_hvc_get_imm(vcpu));
25 vcpu->stat.hvc_exit_stat++;
26
27 ret = kvm_hvc_call_handler(vcpu);
28 if (ret < 0) {
29 vcpu_set_reg(vcpu, 0, ~0UL);
30 return 1;
31 }
32
33 return ret;
34}
35
36static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
37{
38 /*
39 * "If an SMC instruction executed at Non-secure EL1 is
40 * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a
41 * Trap exception, not a Secure Monitor Call exception [...]"
42 *
43 * We need to advance the PC after the trap, as it would
44 * otherwise return to the same address...
45 */
46 vcpu_set_reg(vcpu, 0, ~0UL);
47 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
48 return 1;
49}
50
51/**
52 * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
53 * @vcpu: the vcpu pointer
54 * @run: the kvm_run structure pointer
55 *
56 * WFE: Yield the CPU and come back to this vcpu when the scheduler
57 * decides to.
58 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
59 * world-switches and schedule other host processes until there is an
60 * incoming IRQ or FIQ to the VM.
61 */
62static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
63{
64 if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) {
65 trace_kvm_wfx(*vcpu_pc(vcpu), true);
66 vcpu->stat.wfe_exit_stat++;
67 kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
68 } else {
69 trace_kvm_wfx(*vcpu_pc(vcpu), false);
70 vcpu->stat.wfi_exit_stat++;
71 kvm_vcpu_block(vcpu);
72 kvm_clear_request(KVM_REQ_UNHALT, vcpu);
73 }
74
75 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
76
77 return 1;
78}
79
80static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
81{
82 u32 hsr = kvm_vcpu_get_hsr(vcpu);
83
84 kvm_pr_unimpl("Unknown exception class: hsr: %#08x\n",
85 hsr);
86
87 kvm_inject_undefined(vcpu);
88 return 1;
89}
90
91static exit_handle_fn arm_exit_handlers[] = {
92 [0 ... HSR_EC_MAX] = kvm_handle_unknown_ec,
93 [HSR_EC_WFI] = kvm_handle_wfx,
94 [HSR_EC_CP15_32] = kvm_handle_cp15_32,
95 [HSR_EC_CP15_64] = kvm_handle_cp15_64,
96 [HSR_EC_CP14_MR] = kvm_handle_cp14_32,
97 [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store,
98 [HSR_EC_CP14_64] = kvm_handle_cp14_64,
99 [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access,
100 [HSR_EC_CP10_ID] = kvm_handle_cp10_id,
101 [HSR_EC_HVC] = handle_hvc,
102 [HSR_EC_SMC] = handle_smc,
103 [HSR_EC_IABT] = kvm_handle_guest_abort,
104 [HSR_EC_DABT] = kvm_handle_guest_abort,
105};
106
107static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
108{
109 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
110
111 return arm_exit_handlers[hsr_ec];
112}
113
114/*
115 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
116 * proper exit to userspace.
117 */
118int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
119 int exception_index)
120{
121 exit_handle_fn exit_handler;
122
123 if (ARM_ABORT_PENDING(exception_index)) {
124 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
125
126 /*
127 * HVC/SMC already have an adjusted PC, which we need
128 * to correct in order to return to after having
129 * injected the abort.
130 */
131 if (hsr_ec == HSR_EC_HVC || hsr_ec == HSR_EC_SMC) {
132 u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
133 *vcpu_pc(vcpu) -= adj;
134 }
135
136 kvm_inject_vabt(vcpu);
137 return 1;
138 }
139
140 exception_index = ARM_EXCEPTION_CODE(exception_index);
141
142 switch (exception_index) {
143 case ARM_EXCEPTION_IRQ:
144 return 1;
145 case ARM_EXCEPTION_HVC:
146 /*
147 * See ARM ARM B1.14.1: "Hyp traps on instructions
148 * that fail their condition code check"
149 */
150 if (!kvm_condition_valid(vcpu)) {
151 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
152 return 1;
153 }
154
155 exit_handler = kvm_get_exit_handler(vcpu);
156
157 return exit_handler(vcpu, run);
158 case ARM_EXCEPTION_DATA_ABORT:
159 kvm_inject_vabt(vcpu);
160 return 1;
161 case ARM_EXCEPTION_HYP_GONE:
162 /*
163 * HYP has been reset to the hyp-stub. This happens
164 * when a guest is pre-empted by kvm_reboot()'s
165 * shutdown call.
166 */
167 run->exit_reason = KVM_EXIT_FAIL_ENTRY;
168 return 0;
169 default:
170 kvm_pr_unimpl("Unsupported exception type: %d",
171 exception_index);
172 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
173 return 0;
174 }
175}
1/*
2 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 */
18
19#include <linux/kvm.h>
20#include <linux/kvm_host.h>
21#include <asm/kvm_emulate.h>
22#include <asm/kvm_coproc.h>
23#include <asm/kvm_mmu.h>
24#include <asm/kvm_psci.h>
25#include <trace/events/kvm.h>
26
27#include "trace.h"
28
29typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
30
31static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
32{
33 /* SVC called from Hyp mode should never get here */
34 kvm_debug("SVC called from Hyp mode shouldn't go here\n");
35 BUG();
36 return -EINVAL; /* Squash warning */
37}
38
39static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
40{
41 int ret;
42
43 trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
44 kvm_vcpu_hvc_get_imm(vcpu));
45 vcpu->stat.hvc_exit_stat++;
46
47 ret = kvm_psci_call(vcpu);
48 if (ret < 0) {
49 kvm_inject_undefined(vcpu);
50 return 1;
51 }
52
53 return ret;
54}
55
56static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
57{
58 kvm_inject_undefined(vcpu);
59 return 1;
60}
61
62static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
63{
64 /* The hypervisor should never cause aborts */
65 kvm_err("Prefetch Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
66 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
67 return -EFAULT;
68}
69
70static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
71{
72 /* This is either an error in the ws. code or an external abort */
73 kvm_err("Data Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
74 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
75 return -EFAULT;
76}
77
78/**
79 * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
80 * @vcpu: the vcpu pointer
81 * @run: the kvm_run structure pointer
82 *
83 * WFE: Yield the CPU and come back to this vcpu when the scheduler
84 * decides to.
85 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
86 * world-switches and schedule other host processes until there is an
87 * incoming IRQ or FIQ to the VM.
88 */
89static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
90{
91 if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) {
92 trace_kvm_wfx(*vcpu_pc(vcpu), true);
93 vcpu->stat.wfe_exit_stat++;
94 kvm_vcpu_on_spin(vcpu);
95 } else {
96 trace_kvm_wfx(*vcpu_pc(vcpu), false);
97 vcpu->stat.wfi_exit_stat++;
98 kvm_vcpu_block(vcpu);
99 }
100
101 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
102
103 return 1;
104}
105
106static exit_handle_fn arm_exit_handlers[] = {
107 [HSR_EC_WFI] = kvm_handle_wfx,
108 [HSR_EC_CP15_32] = kvm_handle_cp15_32,
109 [HSR_EC_CP15_64] = kvm_handle_cp15_64,
110 [HSR_EC_CP14_MR] = kvm_handle_cp14_access,
111 [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store,
112 [HSR_EC_CP14_64] = kvm_handle_cp14_access,
113 [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access,
114 [HSR_EC_CP10_ID] = kvm_handle_cp10_id,
115 [HSR_EC_SVC_HYP] = handle_svc_hyp,
116 [HSR_EC_HVC] = handle_hvc,
117 [HSR_EC_SMC] = handle_smc,
118 [HSR_EC_IABT] = kvm_handle_guest_abort,
119 [HSR_EC_IABT_HYP] = handle_pabt_hyp,
120 [HSR_EC_DABT] = kvm_handle_guest_abort,
121 [HSR_EC_DABT_HYP] = handle_dabt_hyp,
122};
123
124static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
125{
126 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
127
128 if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
129 !arm_exit_handlers[hsr_ec]) {
130 kvm_err("Unknown exception class: hsr: %#08x\n",
131 (unsigned int)kvm_vcpu_get_hsr(vcpu));
132 BUG();
133 }
134
135 return arm_exit_handlers[hsr_ec];
136}
137
138/*
139 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
140 * proper exit to userspace.
141 */
142int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
143 int exception_index)
144{
145 exit_handle_fn exit_handler;
146
147 switch (exception_index) {
148 case ARM_EXCEPTION_IRQ:
149 return 1;
150 case ARM_EXCEPTION_HVC:
151 /*
152 * See ARM ARM B1.14.1: "Hyp traps on instructions
153 * that fail their condition code check"
154 */
155 if (!kvm_condition_valid(vcpu)) {
156 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
157 return 1;
158 }
159
160 exit_handler = kvm_get_exit_handler(vcpu);
161
162 return exit_handler(vcpu, run);
163 default:
164 kvm_pr_unimpl("Unsupported exception type: %d",
165 exception_index);
166 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
167 return 0;
168 }
169}