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 it's 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