tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
32{
33 int ret;
34
35 trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
36 kvm_vcpu_hvc_get_imm(vcpu));
37 vcpu->stat.hvc_exit_stat++;
38
39 ret = kvm_psci_call(vcpu);
40 if (ret < 0) {
41 kvm_inject_undefined(vcpu);
42 return 1;
43 }
44
45 return ret;
46}
47
48static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
49{
50 kvm_inject_undefined(vcpu);
51 return 1;
52}
53
54/**
55 * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
56 * @vcpu: the vcpu pointer
57 * @run: the kvm_run structure pointer
58 *
59 * WFE: Yield the CPU and come back to this vcpu when the scheduler
60 * decides to.
61 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
62 * world-switches and schedule other host processes until there is an
63 * incoming IRQ or FIQ to the VM.
64 */
65static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
66{
67 if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) {
68 trace_kvm_wfx(*vcpu_pc(vcpu), true);
69 vcpu->stat.wfe_exit_stat++;
70 kvm_vcpu_on_spin(vcpu);
71 } else {
72 trace_kvm_wfx(*vcpu_pc(vcpu), false);
73 vcpu->stat.wfi_exit_stat++;
74 kvm_vcpu_block(vcpu);
75 }
76
77 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
78
79 return 1;
80}
81
82static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
83{
84 u32 hsr = kvm_vcpu_get_hsr(vcpu);
85
86 kvm_pr_unimpl("Unknown exception class: hsr: %#08x\n",
87 hsr);
88
89 kvm_inject_undefined(vcpu);
90 return 1;
91}
92
93static exit_handle_fn arm_exit_handlers[] = {
94 [0 ... HSR_EC_MAX] = kvm_handle_unknown_ec,
95 [HSR_EC_WFI] = kvm_handle_wfx,
96 [HSR_EC_CP15_32] = kvm_handle_cp15_32,
97 [HSR_EC_CP15_64] = kvm_handle_cp15_64,
98 [HSR_EC_CP14_MR] = kvm_handle_cp14_access,
99 [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store,
100 [HSR_EC_CP14_64] = kvm_handle_cp14_access,
101 [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access,
102 [HSR_EC_CP10_ID] = kvm_handle_cp10_id,
103 [HSR_EC_HVC] = handle_hvc,
104 [HSR_EC_SMC] = handle_smc,
105 [HSR_EC_IABT] = kvm_handle_guest_abort,
106 [HSR_EC_DABT] = kvm_handle_guest_abort,
107};
108
109static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
110{
111 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
112
113 return arm_exit_handlers[hsr_ec];
114}
115
116/*
117 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
118 * proper exit to userspace.
119 */
120int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
121 int exception_index)
122{
123 exit_handle_fn exit_handler;
124
125 if (ARM_ABORT_PENDING(exception_index)) {
126 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
127
128 /*
129 * HVC/SMC already have an adjusted PC, which we need
130 * to correct in order to return to after having
131 * injected the abort.
132 */
133 if (hsr_ec == HSR_EC_HVC || hsr_ec == HSR_EC_SMC) {
134 u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
135 *vcpu_pc(vcpu) -= adj;
136 }
137
138 kvm_inject_vabt(vcpu);
139 return 1;
140 }
141
142 exception_index = ARM_EXCEPTION_CODE(exception_index);
143
144 switch (exception_index) {
145 case ARM_EXCEPTION_IRQ:
146 return 1;
147 case ARM_EXCEPTION_HVC:
148 /*
149 * See ARM ARM B1.14.1: "Hyp traps on instructions
150 * that fail their condition code check"
151 */
152 if (!kvm_condition_valid(vcpu)) {
153 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
154 return 1;
155 }
156
157 exit_handler = kvm_get_exit_handler(vcpu);
158
159 return exit_handler(vcpu, run);
160 case ARM_EXCEPTION_DATA_ABORT:
161 kvm_inject_vabt(vcpu);
162 return 1;
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}