1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright IBM Corp. 2007 16 * Copyright 2011 Freescale Semiconductor, Inc. 17 * 18 * Authors: Hollis Blanchard <hollisb@us.ibm.com> 19 */ 20 21 #include <linux/jiffies.h> 22 #include <linux/hrtimer.h> 23 #include <linux/types.h> 24 #include <linux/string.h> 25 #include <linux/kvm_host.h> 26 #include <linux/clockchips.h> 27 28 #include <asm/reg.h> 29 #include <asm/time.h> 30 #include <asm/byteorder.h> 31 #include <asm/kvm_ppc.h> 32 #include <asm/disassemble.h> 33 #include <asm/ppc-opcode.h> 34 #include "timing.h" 35 #include "trace.h" 36 37 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu) 38 { 39 unsigned long dec_nsec; 40 unsigned long long dec_time; 41 42 pr_debug("mtDEC: %lx\n", vcpu->arch.dec); 43 hrtimer_try_to_cancel(&vcpu->arch.dec_timer); 44 45 #ifdef CONFIG_PPC_BOOK3S 46 /* mtdec lowers the interrupt line when positive. */ 47 kvmppc_core_dequeue_dec(vcpu); 48 #endif 49 50 #ifdef CONFIG_BOOKE 51 /* On BOOKE, DEC = 0 is as good as decrementer not enabled */ 52 if (vcpu->arch.dec == 0) 53 return; 54 #endif 55 56 /* 57 * The decrementer ticks at the same rate as the timebase, so 58 * that's how we convert the guest DEC value to the number of 59 * host ticks. 60 */ 61 62 dec_time = vcpu->arch.dec; 63 /* 64 * Guest timebase ticks at the same frequency as host timebase. 65 * So use the host timebase calculations for decrementer emulation. 66 */ 67 dec_time = tb_to_ns(dec_time); 68 dec_nsec = do_div(dec_time, NSEC_PER_SEC); 69 hrtimer_start(&vcpu->arch.dec_timer, 70 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL); 71 vcpu->arch.dec_jiffies = get_tb(); 72 } 73 74 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb) 75 { 76 u64 jd = tb - vcpu->arch.dec_jiffies; 77 78 #ifdef CONFIG_BOOKE 79 if (vcpu->arch.dec < jd) 80 return 0; 81 #endif 82 83 return vcpu->arch.dec - jd; 84 } 85 86 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs) 87 { 88 enum emulation_result emulated = EMULATE_DONE; 89 ulong spr_val = kvmppc_get_gpr(vcpu, rs); 90 91 switch (sprn) { 92 case SPRN_SRR0: 93 kvmppc_set_srr0(vcpu, spr_val); 94 break; 95 case SPRN_SRR1: 96 kvmppc_set_srr1(vcpu, spr_val); 97 break; 98 99 /* XXX We need to context-switch the timebase for 100 * watchdog and FIT. */ 101 case SPRN_TBWL: break; 102 case SPRN_TBWU: break; 103 104 case SPRN_DEC: 105 vcpu->arch.dec = (u32) spr_val; 106 kvmppc_emulate_dec(vcpu); 107 break; 108 109 case SPRN_SPRG0: 110 kvmppc_set_sprg0(vcpu, spr_val); 111 break; 112 case SPRN_SPRG1: 113 kvmppc_set_sprg1(vcpu, spr_val); 114 break; 115 case SPRN_SPRG2: 116 kvmppc_set_sprg2(vcpu, spr_val); 117 break; 118 case SPRN_SPRG3: 119 kvmppc_set_sprg3(vcpu, spr_val); 120 break; 121 122 /* PIR can legally be written, but we ignore it */ 123 case SPRN_PIR: break; 124 125 default: 126 emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn, 127 spr_val); 128 if (emulated == EMULATE_FAIL) 129 printk(KERN_INFO "mtspr: unknown spr " 130 "0x%x\n", sprn); 131 break; 132 } 133 134 kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS); 135 136 return emulated; 137 } 138 139 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) 140 { 141 enum emulation_result emulated = EMULATE_DONE; 142 ulong spr_val = 0; 143 144 switch (sprn) { 145 case SPRN_SRR0: 146 spr_val = kvmppc_get_srr0(vcpu); 147 break; 148 case SPRN_SRR1: 149 spr_val = kvmppc_get_srr1(vcpu); 150 break; 151 case SPRN_PVR: 152 spr_val = vcpu->arch.pvr; 153 break; 154 case SPRN_PIR: 155 spr_val = vcpu->vcpu_id; 156 break; 157 158 /* Note: mftb and TBRL/TBWL are user-accessible, so 159 * the guest can always access the real TB anyways. 160 * In fact, we probably will never see these traps. */ 161 case SPRN_TBWL: 162 spr_val = get_tb() >> 32; 163 break; 164 case SPRN_TBWU: 165 spr_val = get_tb(); 166 break; 167 168 case SPRN_SPRG0: 169 spr_val = kvmppc_get_sprg0(vcpu); 170 break; 171 case SPRN_SPRG1: 172 spr_val = kvmppc_get_sprg1(vcpu); 173 break; 174 case SPRN_SPRG2: 175 spr_val = kvmppc_get_sprg2(vcpu); 176 break; 177 case SPRN_SPRG3: 178 spr_val = kvmppc_get_sprg3(vcpu); 179 break; 180 /* Note: SPRG4-7 are user-readable, so we don't get 181 * a trap. */ 182 183 case SPRN_DEC: 184 spr_val = kvmppc_get_dec(vcpu, get_tb()); 185 break; 186 default: 187 emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn, 188 &spr_val); 189 if (unlikely(emulated == EMULATE_FAIL)) { 190 printk(KERN_INFO "mfspr: unknown spr " 191 "0x%x\n", sprn); 192 } 193 break; 194 } 195 196 if (emulated == EMULATE_DONE) 197 kvmppc_set_gpr(vcpu, rt, spr_val); 198 kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS); 199 200 return emulated; 201 } 202 203 /* XXX Should probably auto-generate instruction decoding for a particular core 204 * from opcode tables in the future. */ 205 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) 206 { 207 u32 inst; 208 int rs, rt, sprn; 209 enum emulation_result emulated; 210 int advance = 1; 211 212 /* this default type might be overwritten by subcategories */ 213 kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); 214 215 emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); 216 if (emulated != EMULATE_DONE) 217 return emulated; 218 219 pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); 220 221 rs = get_rs(inst); 222 rt = get_rt(inst); 223 sprn = get_sprn(inst); 224 225 switch (get_op(inst)) { 226 case OP_TRAP: 227 #ifdef CONFIG_PPC_BOOK3S 228 case OP_TRAP_64: 229 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 230 #else 231 kvmppc_core_queue_program(vcpu, 232 vcpu->arch.shared->esr | ESR_PTR); 233 #endif 234 advance = 0; 235 break; 236 237 case 31: 238 switch (get_xop(inst)) { 239 240 case OP_31_XOP_TRAP: 241 #ifdef CONFIG_64BIT 242 case OP_31_XOP_TRAP_64: 243 #endif 244 #ifdef CONFIG_PPC_BOOK3S 245 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 246 #else 247 kvmppc_core_queue_program(vcpu, 248 vcpu->arch.shared->esr | ESR_PTR); 249 #endif 250 advance = 0; 251 break; 252 253 case OP_31_XOP_MFSPR: 254 emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt); 255 if (emulated == EMULATE_AGAIN) { 256 emulated = EMULATE_DONE; 257 advance = 0; 258 } 259 break; 260 261 case OP_31_XOP_MTSPR: 262 emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs); 263 if (emulated == EMULATE_AGAIN) { 264 emulated = EMULATE_DONE; 265 advance = 0; 266 } 267 break; 268 269 case OP_31_XOP_TLBSYNC: 270 break; 271 272 default: 273 /* Attempt core-specific emulation below. */ 274 emulated = EMULATE_FAIL; 275 } 276 break; 277 278 case 0: 279 /* 280 * Instruction with primary opcode 0. Based on PowerISA 281 * these are illegal instructions. 282 */ 283 if (inst == KVMPPC_INST_SW_BREAKPOINT) { 284 run->exit_reason = KVM_EXIT_DEBUG; 285 run->debug.arch.address = kvmppc_get_pc(vcpu); 286 emulated = EMULATE_EXIT_USER; 287 advance = 0; 288 } else 289 emulated = EMULATE_FAIL; 290 291 break; 292 293 default: 294 emulated = EMULATE_FAIL; 295 } 296 297 if (emulated == EMULATE_FAIL) { 298 emulated = vcpu->kvm->arch.kvm_ops->emulate_op(run, vcpu, inst, 299 &advance); 300 if (emulated == EMULATE_AGAIN) { 301 advance = 0; 302 } else if (emulated == EMULATE_FAIL) { 303 advance = 0; 304 printk(KERN_ERR "Couldn't emulate instruction 0x%08x " 305 "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst)); 306 } 307 } 308 309 trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated); 310 311 /* Advance past emulated instruction. */ 312 if (advance) 313 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4); 314 315 return emulated; 316 } 317 EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction); 318