1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Fault injection for both 32 and 64bit guests.
4 *
5 * Copyright (C) 2012,2013 - ARM Ltd
6 * Author: Marc Zyngier <marc.zyngier@arm.com>
7 *
8 * Based on arch/arm/kvm/emulate.c
9 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
10 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
11 */
12
13 #include <linux/kvm_host.h>
14 #include <asm/kvm_emulate.h>
15 #include <asm/kvm_nested.h>
16 #include <asm/esr.h>
17
pend_sync_exception(struct kvm_vcpu * vcpu)18 static void pend_sync_exception(struct kvm_vcpu *vcpu)
19 {
20 /* If not nesting, EL1 is the only possible exception target */
21 if (likely(!vcpu_has_nv(vcpu))) {
22 kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
23 return;
24 }
25
26 /*
27 * With NV, we need to pick between EL1 and EL2. Note that we
28 * never deal with a nesting exception here, hence never
29 * changing context, and the exception itself can be delayed
30 * until the next entry.
31 */
32 switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) {
33 case PSR_MODE_EL2h:
34 case PSR_MODE_EL2t:
35 kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
36 break;
37 case PSR_MODE_EL1h:
38 case PSR_MODE_EL1t:
39 kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
40 break;
41 case PSR_MODE_EL0t:
42 if (vcpu_el2_tge_is_set(vcpu))
43 kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
44 else
45 kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
46 break;
47 default:
48 BUG();
49 }
50 }
51
match_target_el(struct kvm_vcpu * vcpu,unsigned long target)52 static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target)
53 {
54 return (vcpu_get_flag(vcpu, EXCEPT_MASK) == target);
55 }
56
inject_abt64(struct kvm_vcpu * vcpu,bool is_iabt,unsigned long addr)57 static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
58 {
59 unsigned long cpsr = *vcpu_cpsr(vcpu);
60 bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
61 u64 esr = 0;
62
63 pend_sync_exception(vcpu);
64
65 /*
66 * Build an {i,d}abort, depending on the level and the
67 * instruction set. Report an external synchronous abort.
68 */
69 if (kvm_vcpu_trap_il_is32bit(vcpu))
70 esr |= ESR_ELx_IL;
71
72 /*
73 * Here, the guest runs in AArch64 mode when in EL1. If we get
74 * an AArch32 fault, it means we managed to trap an EL0 fault.
75 */
76 if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
77 esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
78 else
79 esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
80
81 if (!is_iabt)
82 esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
83
84 esr |= ESR_ELx_FSC_EXTABT;
85
86 if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC))) {
87 vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
88 vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
89 } else {
90 vcpu_write_sys_reg(vcpu, addr, FAR_EL2);
91 vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
92 }
93 }
94
inject_undef64(struct kvm_vcpu * vcpu)95 static void inject_undef64(struct kvm_vcpu *vcpu)
96 {
97 u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
98
99 pend_sync_exception(vcpu);
100
101 /*
102 * Build an unknown exception, depending on the instruction
103 * set.
104 */
105 if (kvm_vcpu_trap_il_is32bit(vcpu))
106 esr |= ESR_ELx_IL;
107
108 if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC)))
109 vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
110 else
111 vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
112 }
113
114 #define DFSR_FSC_EXTABT_LPAE 0x10
115 #define DFSR_FSC_EXTABT_nLPAE 0x08
116 #define DFSR_LPAE BIT(9)
117 #define TTBCR_EAE BIT(31)
118
inject_undef32(struct kvm_vcpu * vcpu)119 static void inject_undef32(struct kvm_vcpu *vcpu)
120 {
121 kvm_pend_exception(vcpu, EXCEPT_AA32_UND);
122 }
123
124 /*
125 * Modelled after TakeDataAbortException() and TakePrefetchAbortException
126 * pseudocode.
127 */
inject_abt32(struct kvm_vcpu * vcpu,bool is_pabt,u32 addr)128 static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
129 {
130 u64 far;
131 u32 fsr;
132
133 /* Give the guest an IMPLEMENTATION DEFINED exception */
134 if (vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) {
135 fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE;
136 } else {
137 /* no need to shuffle FS[4] into DFSR[10] as its 0 */
138 fsr = DFSR_FSC_EXTABT_nLPAE;
139 }
140
141 far = vcpu_read_sys_reg(vcpu, FAR_EL1);
142
143 if (is_pabt) {
144 kvm_pend_exception(vcpu, EXCEPT_AA32_IABT);
145 far &= GENMASK(31, 0);
146 far |= (u64)addr << 32;
147 vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2);
148 } else { /* !iabt */
149 kvm_pend_exception(vcpu, EXCEPT_AA32_DABT);
150 far &= GENMASK(63, 32);
151 far |= addr;
152 vcpu_write_sys_reg(vcpu, fsr, ESR_EL1);
153 }
154
155 vcpu_write_sys_reg(vcpu, far, FAR_EL1);
156 }
157
158 /**
159 * kvm_inject_dabt - inject a data abort into the guest
160 * @vcpu: The VCPU to receive the data abort
161 * @addr: The address to report in the DFAR
162 *
163 * It is assumed that this code is called from the VCPU thread and that the
164 * VCPU therefore is not currently executing guest code.
165 */
kvm_inject_dabt(struct kvm_vcpu * vcpu,unsigned long addr)166 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
167 {
168 if (vcpu_el1_is_32bit(vcpu))
169 inject_abt32(vcpu, false, addr);
170 else
171 inject_abt64(vcpu, false, addr);
172 }
173
174 /**
175 * kvm_inject_pabt - inject a prefetch abort into the guest
176 * @vcpu: The VCPU to receive the prefetch abort
177 * @addr: The address to report in the DFAR
178 *
179 * It is assumed that this code is called from the VCPU thread and that the
180 * VCPU therefore is not currently executing guest code.
181 */
kvm_inject_pabt(struct kvm_vcpu * vcpu,unsigned long addr)182 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
183 {
184 if (vcpu_el1_is_32bit(vcpu))
185 inject_abt32(vcpu, true, addr);
186 else
187 inject_abt64(vcpu, true, addr);
188 }
189
kvm_inject_size_fault(struct kvm_vcpu * vcpu)190 void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
191 {
192 unsigned long addr, esr;
193
194 addr = kvm_vcpu_get_fault_ipa(vcpu);
195 addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
196
197 if (kvm_vcpu_trap_is_iabt(vcpu))
198 kvm_inject_pabt(vcpu, addr);
199 else
200 kvm_inject_dabt(vcpu, addr);
201
202 /*
203 * If AArch64 or LPAE, set FSC to 0 to indicate an Address
204 * Size Fault at level 0, as if exceeding PARange.
205 *
206 * Non-LPAE guests will only get the external abort, as there
207 * is no way to describe the ASF.
208 */
209 if (vcpu_el1_is_32bit(vcpu) &&
210 !(vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE))
211 return;
212
213 esr = vcpu_read_sys_reg(vcpu, ESR_EL1);
214 esr &= ~GENMASK_ULL(5, 0);
215 vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
216 }
217
218 /**
219 * kvm_inject_undefined - inject an undefined instruction into the guest
220 * @vcpu: The vCPU in which to inject the exception
221 *
222 * It is assumed that this code is called from the VCPU thread and that the
223 * VCPU therefore is not currently executing guest code.
224 */
kvm_inject_undefined(struct kvm_vcpu * vcpu)225 void kvm_inject_undefined(struct kvm_vcpu *vcpu)
226 {
227 if (vcpu_el1_is_32bit(vcpu))
228 inject_undef32(vcpu);
229 else
230 inject_undef64(vcpu);
231 }
232
kvm_set_sei_esr(struct kvm_vcpu * vcpu,u64 esr)233 void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr)
234 {
235 vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
236 *vcpu_hcr(vcpu) |= HCR_VSE;
237 }
238
239 /**
240 * kvm_inject_vabt - inject an async abort / SError into the guest
241 * @vcpu: The VCPU to receive the exception
242 *
243 * It is assumed that this code is called from the VCPU thread and that the
244 * VCPU therefore is not currently executing guest code.
245 *
246 * Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with
247 * the remaining ISS all-zeros so that this error is not interpreted as an
248 * uncategorized RAS error. Without the RAS Extensions we can't specify an ESR
249 * value, so the CPU generates an imp-def value.
250 */
kvm_inject_vabt(struct kvm_vcpu * vcpu)251 void kvm_inject_vabt(struct kvm_vcpu *vcpu)
252 {
253 kvm_set_sei_esr(vcpu, ESR_ELx_ISV);
254 }
255