summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/inject_fault.c
blob: 64c3aec0d937c36b84d49b7ca403933429b993c8 (plain)
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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Fault injection for both 32 and 64bit guests.
 *
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * Based on arch/arm/kvm/emulate.c
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_nested.h>
#include <asm/esr.h>

static void pend_sync_exception(struct kvm_vcpu *vcpu)
{
	/* If not nesting, EL1 is the only possible exception target */
	if (likely(!vcpu_has_nv(vcpu))) {
		kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
		return;
	}

	/*
	 * With NV, we need to pick between EL1 and EL2. Note that we
	 * never deal with a nesting exception here, hence never
	 * changing context, and the exception itself can be delayed
	 * until the next entry.
	 */
	switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) {
	case PSR_MODE_EL2h:
	case PSR_MODE_EL2t:
		kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
		break;
	case PSR_MODE_EL1h:
	case PSR_MODE_EL1t:
		kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
		break;
	case PSR_MODE_EL0t:
		if (vcpu_el2_tge_is_set(vcpu))
			kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
		else
			kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
		break;
	default:
		BUG();
	}
}

static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target)
{
	return (vcpu_get_flag(vcpu, EXCEPT_MASK) == target);
}

static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
{
	unsigned long cpsr = *vcpu_cpsr(vcpu);
	bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
	u64 esr = 0;

	pend_sync_exception(vcpu);

	/*
	 * Build an {i,d}abort, depending on the level and the
	 * instruction set. Report an external synchronous abort.
	 */
	if (kvm_vcpu_trap_il_is32bit(vcpu))
		esr |= ESR_ELx_IL;

	/*
	 * Here, the guest runs in AArch64 mode when in EL1. If we get
	 * an AArch32 fault, it means we managed to trap an EL0 fault.
	 */
	if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
		esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
	else
		esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);

	if (!is_iabt)
		esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;

	esr |= ESR_ELx_FSC_EXTABT;

	if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC))) {
		vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
		vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
	} else {
		vcpu_write_sys_reg(vcpu, addr, FAR_EL2);
		vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
	}
}

static void inject_undef64(struct kvm_vcpu *vcpu)
{
	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);

	pend_sync_exception(vcpu);

	/*
	 * Build an unknown exception, depending on the instruction
	 * set.
	 */
	if (kvm_vcpu_trap_il_is32bit(vcpu))
		esr |= ESR_ELx_IL;

	if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC)))
		vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
	else
		vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
}

#define DFSR_FSC_EXTABT_LPAE	0x10
#define DFSR_FSC_EXTABT_nLPAE	0x08
#define DFSR_LPAE		BIT(9)
#define TTBCR_EAE		BIT(31)

static void inject_undef32(struct kvm_vcpu *vcpu)
{
	kvm_pend_exception(vcpu, EXCEPT_AA32_UND);
}

/*
 * Modelled after TakeDataAbortException() and TakePrefetchAbortException
 * pseudocode.
 */
static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
{
	u64 far;
	u32 fsr;

	/* Give the guest an IMPLEMENTATION DEFINED exception */
	if (vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) {
		fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE;
	} else {
		/* no need to shuffle FS[4] into DFSR[10] as its 0 */
		fsr = DFSR_FSC_EXTABT_nLPAE;
	}

	far = vcpu_read_sys_reg(vcpu, FAR_EL1);

	if (is_pabt) {
		kvm_pend_exception(vcpu, EXCEPT_AA32_IABT);
		far &= GENMASK(31, 0);
		far |= (u64)addr << 32;
		vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2);
	} else { /* !iabt */
		kvm_pend_exception(vcpu, EXCEPT_AA32_DABT);
		far &= GENMASK(63, 32);
		far |= addr;
		vcpu_write_sys_reg(vcpu, fsr, ESR_EL1);
	}

	vcpu_write_sys_reg(vcpu, far, FAR_EL1);
}

/**
 * kvm_inject_dabt - inject a data abort into the guest
 * @vcpu: The VCPU to receive the data abort
 * @addr: The address to report in the DFAR
 *
 * It is assumed that this code is called from the VCPU thread and that the
 * VCPU therefore is not currently executing guest code.
 */
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
{
	if (vcpu_el1_is_32bit(vcpu))
		inject_abt32(vcpu, false, addr);
	else
		inject_abt64(vcpu, false, addr);
}

/**
 * kvm_inject_pabt - inject a prefetch abort into the guest
 * @vcpu: The VCPU to receive the prefetch abort
 * @addr: The address to report in the DFAR
 *
 * It is assumed that this code is called from the VCPU thread and that the
 * VCPU therefore is not currently executing guest code.
 */
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
{
	if (vcpu_el1_is_32bit(vcpu))
		inject_abt32(vcpu, true, addr);
	else
		inject_abt64(vcpu, true, addr);
}

void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
{
	unsigned long addr, esr;

	addr  = kvm_vcpu_get_fault_ipa(vcpu);
	addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);

	if (kvm_vcpu_trap_is_iabt(vcpu))
		kvm_inject_pabt(vcpu, addr);
	else
		kvm_inject_dabt(vcpu, addr);

	/*
	 * If AArch64 or LPAE, set FSC to 0 to indicate an Address
	 * Size Fault at level 0, as if exceeding PARange.
	 *
	 * Non-LPAE guests will only get the external abort, as there
	 * is no way to to describe the ASF.
	 */
	if (vcpu_el1_is_32bit(vcpu) &&
	    !(vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE))
		return;

	esr = vcpu_read_sys_reg(vcpu, ESR_EL1);
	esr &= ~GENMASK_ULL(5, 0);
	vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
}

/**
 * kvm_inject_undefined - inject an undefined instruction into the guest
 * @vcpu: The vCPU in which to inject the exception
 *
 * It is assumed that this code is called from the VCPU thread and that the
 * VCPU therefore is not currently executing guest code.
 */
void kvm_inject_undefined(struct kvm_vcpu *vcpu)
{
	if (vcpu_el1_is_32bit(vcpu))
		inject_undef32(vcpu);
	else
		inject_undef64(vcpu);
}

void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr)
{
	vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
	*vcpu_hcr(vcpu) |= HCR_VSE;
}

/**
 * kvm_inject_vabt - inject an async abort / SError into the guest
 * @vcpu: The VCPU to receive the exception
 *
 * It is assumed that this code is called from the VCPU thread and that the
 * VCPU therefore is not currently executing guest code.
 *
 * Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with
 * the remaining ISS all-zeros so that this error is not interpreted as an
 * uncategorized RAS error. Without the RAS Extensions we can't specify an ESR
 * value, so the CPU generates an imp-def value.
 */
void kvm_inject_vabt(struct kvm_vcpu *vcpu)
{
	kvm_set_sei_esr(vcpu, ESR_ELx_ISV);
}