1 /* 2 * Fault injection for both 32 and 64bit guests. 3 * 4 * Copyright (C) 2012,2013 - ARM Ltd 5 * Author: Marc Zyngier <marc.zyngier@arm.com> 6 * 7 * Based on arch/arm/kvm/emulate.c 8 * Copyright (C) 2012 - Virtual Open Systems and Columbia University 9 * Author: Christoffer Dall <c.dall@virtualopensystems.com> 10 * 11 * This program is free software: you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program. If not, see <http://www.gnu.org/licenses/>. 22 */ 23 24 #include <linux/kvm_host.h> 25 #include <asm/kvm_emulate.h> 26 #include <asm/esr.h> 27 28 #define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \ 29 PSR_I_BIT | PSR_D_BIT) 30 31 #define CURRENT_EL_SP_EL0_VECTOR 0x0 32 #define CURRENT_EL_SP_ELx_VECTOR 0x200 33 #define LOWER_EL_AArch64_VECTOR 0x400 34 #define LOWER_EL_AArch32_VECTOR 0x600 35 36 static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset) 37 { 38 unsigned long cpsr; 39 unsigned long new_spsr_value = *vcpu_cpsr(vcpu); 40 bool is_thumb = (new_spsr_value & COMPAT_PSR_T_BIT); 41 u32 return_offset = (is_thumb) ? 4 : 0; 42 u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR); 43 44 cpsr = mode | COMPAT_PSR_I_BIT; 45 46 if (sctlr & (1 << 30)) 47 cpsr |= COMPAT_PSR_T_BIT; 48 if (sctlr & (1 << 25)) 49 cpsr |= COMPAT_PSR_E_BIT; 50 51 *vcpu_cpsr(vcpu) = cpsr; 52 53 /* Note: These now point to the banked copies */ 54 *vcpu_spsr(vcpu) = new_spsr_value; 55 *vcpu_reg32(vcpu, 14) = *vcpu_pc(vcpu) + return_offset; 56 57 /* Branch to exception vector */ 58 if (sctlr & (1 << 13)) 59 vect_offset += 0xffff0000; 60 else /* always have security exceptions */ 61 vect_offset += vcpu_cp15(vcpu, c12_VBAR); 62 63 *vcpu_pc(vcpu) = vect_offset; 64 } 65 66 static void inject_undef32(struct kvm_vcpu *vcpu) 67 { 68 prepare_fault32(vcpu, COMPAT_PSR_MODE_UND, 4); 69 } 70 71 /* 72 * Modelled after TakeDataAbortException() and TakePrefetchAbortException 73 * pseudocode. 74 */ 75 static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, 76 unsigned long addr) 77 { 78 u32 vect_offset; 79 u32 *far, *fsr; 80 bool is_lpae; 81 82 if (is_pabt) { 83 vect_offset = 12; 84 far = &vcpu_cp15(vcpu, c6_IFAR); 85 fsr = &vcpu_cp15(vcpu, c5_IFSR); 86 } else { /* !iabt */ 87 vect_offset = 16; 88 far = &vcpu_cp15(vcpu, c6_DFAR); 89 fsr = &vcpu_cp15(vcpu, c5_DFSR); 90 } 91 92 prepare_fault32(vcpu, COMPAT_PSR_MODE_ABT | COMPAT_PSR_A_BIT, vect_offset); 93 94 *far = addr; 95 96 /* Give the guest an IMPLEMENTATION DEFINED exception */ 97 is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); 98 if (is_lpae) 99 *fsr = 1 << 9 | 0x34; 100 else 101 *fsr = 0x14; 102 } 103 104 enum exception_type { 105 except_type_sync = 0, 106 except_type_irq = 0x80, 107 except_type_fiq = 0x100, 108 except_type_serror = 0x180, 109 }; 110 111 static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type) 112 { 113 u64 exc_offset; 114 115 switch (*vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT)) { 116 case PSR_MODE_EL1t: 117 exc_offset = CURRENT_EL_SP_EL0_VECTOR; 118 break; 119 case PSR_MODE_EL1h: 120 exc_offset = CURRENT_EL_SP_ELx_VECTOR; 121 break; 122 case PSR_MODE_EL0t: 123 exc_offset = LOWER_EL_AArch64_VECTOR; 124 break; 125 default: 126 exc_offset = LOWER_EL_AArch32_VECTOR; 127 } 128 129 return vcpu_sys_reg(vcpu, VBAR_EL1) + exc_offset + type; 130 } 131 132 static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) 133 { 134 unsigned long cpsr = *vcpu_cpsr(vcpu); 135 bool is_aarch32; 136 u32 esr = 0; 137 138 is_aarch32 = vcpu_mode_is_32bit(vcpu); 139 140 *vcpu_spsr(vcpu) = cpsr; 141 *vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu); 142 143 *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); 144 *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; 145 146 vcpu_sys_reg(vcpu, FAR_EL1) = addr; 147 148 /* 149 * Build an {i,d}abort, depending on the level and the 150 * instruction set. Report an external synchronous abort. 151 */ 152 if (kvm_vcpu_trap_il_is32bit(vcpu)) 153 esr |= ESR_ELx_IL; 154 155 /* 156 * Here, the guest runs in AArch64 mode when in EL1. If we get 157 * an AArch32 fault, it means we managed to trap an EL0 fault. 158 */ 159 if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t) 160 esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT); 161 else 162 esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT); 163 164 if (!is_iabt) 165 esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; 166 167 vcpu_sys_reg(vcpu, ESR_EL1) = esr | ESR_ELx_FSC_EXTABT; 168 } 169 170 static void inject_undef64(struct kvm_vcpu *vcpu) 171 { 172 unsigned long cpsr = *vcpu_cpsr(vcpu); 173 u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); 174 175 *vcpu_spsr(vcpu) = cpsr; 176 *vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu); 177 178 *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); 179 *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; 180 181 /* 182 * Build an unknown exception, depending on the instruction 183 * set. 184 */ 185 if (kvm_vcpu_trap_il_is32bit(vcpu)) 186 esr |= ESR_ELx_IL; 187 188 vcpu_sys_reg(vcpu, ESR_EL1) = esr; 189 } 190 191 /** 192 * kvm_inject_dabt - inject a data abort into the guest 193 * @vcpu: The VCPU to receive the undefined exception 194 * @addr: The address to report in the DFAR 195 * 196 * It is assumed that this code is called from the VCPU thread and that the 197 * VCPU therefore is not currently executing guest code. 198 */ 199 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr) 200 { 201 if (!(vcpu->arch.hcr_el2 & HCR_RW)) 202 inject_abt32(vcpu, false, addr); 203 else 204 inject_abt64(vcpu, false, addr); 205 } 206 207 /** 208 * kvm_inject_pabt - inject a prefetch abort into the guest 209 * @vcpu: The VCPU to receive the undefined exception 210 * @addr: The address to report in the DFAR 211 * 212 * It is assumed that this code is called from the VCPU thread and that the 213 * VCPU therefore is not currently executing guest code. 214 */ 215 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr) 216 { 217 if (!(vcpu->arch.hcr_el2 & HCR_RW)) 218 inject_abt32(vcpu, true, addr); 219 else 220 inject_abt64(vcpu, true, addr); 221 } 222 223 /** 224 * kvm_inject_undefined - inject an undefined instruction into the guest 225 * 226 * It is assumed that this code is called from the VCPU thread and that the 227 * VCPU therefore is not currently executing guest code. 228 */ 229 void kvm_inject_undefined(struct kvm_vcpu *vcpu) 230 { 231 if (!(vcpu->arch.hcr_el2 & HCR_RW)) 232 inject_undef32(vcpu); 233 else 234 inject_undef64(vcpu); 235 } 236