aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/kvm/handle_exit.c
blob: 4c979d466cc1681c4b3efc70623345eee5974b78 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_psci.h>
#include <trace/events/kvm.h>

#include "trace.h"

typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);

static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	/* SVC called from Hyp mode should never get here */
	kvm_debug("SVC called from Hyp mode shouldn't go here\n");
	BUG();
	return -EINVAL; /* Squash warning */
}

static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	int ret;

	trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
		      kvm_vcpu_hvc_get_imm(vcpu));

	ret = kvm_psci_call(vcpu);
	if (ret < 0) {
		kvm_inject_undefined(vcpu);
		return 1;
	}

	return ret;
}

static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	kvm_inject_undefined(vcpu);
	return 1;
}

static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	/* The hypervisor should never cause aborts */
	kvm_err("Prefetch Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
		kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
	return -EFAULT;
}

static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	/* This is either an error in the ws. code or an external abort */
	kvm_err("Data Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
		kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
	return -EFAULT;
}

/**
 * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
 * @vcpu:	the vcpu pointer
 * @run:	the kvm_run structure pointer
 *
 * WFE: Yield the CPU and come back to this vcpu when the scheduler
 * decides to.
 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
 * world-switches and schedule other host processes until there is an
 * incoming IRQ or FIQ to the VM.
 */
static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	trace_kvm_wfi(*vcpu_pc(vcpu));
	if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE)
		kvm_vcpu_on_spin(vcpu);
	else
		kvm_vcpu_block(vcpu);

	return 1;
}

static exit_handle_fn arm_exit_handlers[] = {
	[HSR_EC_WFI]		= kvm_handle_wfx,
	[HSR_EC_CP15_32]	= kvm_handle_cp15_32,
	[HSR_EC_CP15_64]	= kvm_handle_cp15_64,
	[HSR_EC_CP14_MR]	= kvm_handle_cp14_access,
	[HSR_EC_CP14_LS]	= kvm_handle_cp14_load_store,
	[HSR_EC_CP14_64]	= kvm_handle_cp14_access,
	[HSR_EC_CP_0_13]	= kvm_handle_cp_0_13_access,
	[HSR_EC_CP10_ID]	= kvm_handle_cp10_id,
	[HSR_EC_SVC_HYP]	= handle_svc_hyp,
	[HSR_EC_HVC]		= handle_hvc,
	[HSR_EC_SMC]		= handle_smc,
	[HSR_EC_IABT]		= kvm_handle_guest_abort,
	[HSR_EC_IABT_HYP]	= handle_pabt_hyp,
	[HSR_EC_DABT]		= kvm_handle_guest_abort,
	[HSR_EC_DABT_HYP]	= handle_dabt_hyp,
};

static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
{
	u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);

	if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
	    !arm_exit_handlers[hsr_ec]) {
		kvm_err("Unknown exception class: hsr: %#08x\n",
			(unsigned int)kvm_vcpu_get_hsr(vcpu));
		BUG();
	}

	return arm_exit_handlers[hsr_ec];
}

/*
 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
 * proper exit to userspace.
 */
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
		       int exception_index)
{
	exit_handle_fn exit_handler;

	switch (exception_index) {
	case ARM_EXCEPTION_IRQ:
		return 1;
	case ARM_EXCEPTION_UNDEFINED:
		kvm_err("Undefined exception in Hyp mode at: %#08lx\n",
			kvm_vcpu_get_hyp_pc(vcpu));
		BUG();
		panic("KVM: Hypervisor undefined exception!\n");
	case ARM_EXCEPTION_DATA_ABORT:
	case ARM_EXCEPTION_PREF_ABORT:
	case ARM_EXCEPTION_HVC:
		/*
		 * See ARM ARM B1.14.1: "Hyp traps on instructions
		 * that fail their condition code check"
		 */
		if (!kvm_condition_valid(vcpu)) {
			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
			return 1;
		}

		exit_handler = kvm_get_exit_handler(vcpu);

		return exit_handler(vcpu, run);
	default:
		kvm_pr_unimpl("Unsupported exception type: %d",
			      exception_index);
		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
		return 0;
	}
}