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_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 trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
42 kvm_vcpu_hvc_get_imm(vcpu));
43
44 if (kvm_psci_call(vcpu))
45 return 1;
46
47 kvm_inject_undefined(vcpu);
48 return 1;
49}
50
51static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
52{
53 kvm_inject_undefined(vcpu);
54 return 1;
55}
56
57static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
58{
59 /* The hypervisor should never cause aborts */
60 kvm_err("Prefetch Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
61 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
62 return -EFAULT;
63}
64
65static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
66{
67 /* This is either an error in the ws. code or an external abort */
68 kvm_err("Data Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
69 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
70 return -EFAULT;
71}
72
73/**
74 * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
75 * @vcpu: the vcpu pointer
76 * @run: the kvm_run structure pointer
77 *
78 * WFE: Yield the CPU and come back to this vcpu when the scheduler
79 * decides to.
80 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
81 * world-switches and schedule other host processes until there is an
82 * incoming IRQ or FIQ to the VM.
83 */
84static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
85{
86 trace_kvm_wfi(*vcpu_pc(vcpu));
87 if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE)
88 kvm_vcpu_on_spin(vcpu);
89 else
90 kvm_vcpu_block(vcpu);
91
92 return 1;
93}
94
95static exit_handle_fn arm_exit_handlers[] = {
96 [HSR_EC_WFI] = kvm_handle_wfx,
97 [HSR_EC_CP15_32] = kvm_handle_cp15_32,
98 [HSR_EC_CP15_64] = kvm_handle_cp15_64,
99 [HSR_EC_CP14_MR] = kvm_handle_cp14_access,
100 [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store,
101 [HSR_EC_CP14_64] = kvm_handle_cp14_access,
102 [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access,
103 [HSR_EC_CP10_ID] = kvm_handle_cp10_id,
104 [HSR_EC_SVC_HYP] = handle_svc_hyp,
105 [HSR_EC_HVC] = handle_hvc,
106 [HSR_EC_SMC] = handle_smc,
107 [HSR_EC_IABT] = kvm_handle_guest_abort,
108 [HSR_EC_IABT_HYP] = handle_pabt_hyp,
109 [HSR_EC_DABT] = kvm_handle_guest_abort,
110 [HSR_EC_DABT_HYP] = handle_dabt_hyp,
111};
112
113static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
114{
115 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
116
117 if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
118 !arm_exit_handlers[hsr_ec]) {
119 kvm_err("Unknown exception class: hsr: %#08x\n",
120 (unsigned int)kvm_vcpu_get_hsr(vcpu));
121 BUG();
122 }
123
124 return arm_exit_handlers[hsr_ec];
125}
126
127/*
128 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
129 * proper exit to userspace.
130 */
131int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
132 int exception_index)
133{
134 exit_handle_fn exit_handler;
135
136 switch (exception_index) {
137 case ARM_EXCEPTION_IRQ:
138 return 1;
139 case ARM_EXCEPTION_UNDEFINED:
140 kvm_err("Undefined exception in Hyp mode at: %#08lx\n",
141 kvm_vcpu_get_hyp_pc(vcpu));
142 BUG();
143 panic("KVM: Hypervisor undefined exception!\n");
144 case ARM_EXCEPTION_DATA_ABORT:
145 case ARM_EXCEPTION_PREF_ABORT:
146 case ARM_EXCEPTION_HVC:
147 /*
148 * See ARM ARM B1.14.1: "Hyp traps on instructions
149 * that fail their condition code check"
150 */
151 if (!kvm_condition_valid(vcpu)) {
152 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
153 return 1;
154 }
155
156 exit_handler = kvm_get_exit_handler(vcpu);
157
158 return exit_handler(vcpu, run);
159 default:
160 kvm_pr_unimpl("Unsupported exception type: %d",
161 exception_index);
162 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
163 return 0;
164 }
165}