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 decrementer. 65 * So use the host decrementer calculations for decrementer emulation. 66 */ 67 dec_time = dec_time << decrementer_clockevent.shift; 68 do_div(dec_time, decrementer_clockevent.mult); 69 dec_nsec = do_div(dec_time, NSEC_PER_SEC); 70 hrtimer_start(&vcpu->arch.dec_timer, 71 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL); 72 vcpu->arch.dec_jiffies = get_tb(); 73 } 74 75 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb) 76 { 77 u64 jd = tb - vcpu->arch.dec_jiffies; 78 79 #ifdef CONFIG_BOOKE 80 if (vcpu->arch.dec < jd) 81 return 0; 82 #endif 83 84 return vcpu->arch.dec - jd; 85 } 86 87 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs) 88 { 89 enum emulation_result emulated = EMULATE_DONE; 90 ulong spr_val = kvmppc_get_gpr(vcpu, rs); 91 92 switch (sprn) { 93 case SPRN_SRR0: 94 kvmppc_set_srr0(vcpu, spr_val); 95 break; 96 case SPRN_SRR1: 97 kvmppc_set_srr1(vcpu, spr_val); 98 break; 99 100 /* XXX We need to context-switch the timebase for 101 * watchdog and FIT. */ 102 case SPRN_TBWL: break; 103 case SPRN_TBWU: break; 104 105 case SPRN_DEC: 106 vcpu->arch.dec = (u32) spr_val; 107 kvmppc_emulate_dec(vcpu); 108 break; 109 110 case SPRN_SPRG0: 111 kvmppc_set_sprg0(vcpu, spr_val); 112 break; 113 case SPRN_SPRG1: 114 kvmppc_set_sprg1(vcpu, spr_val); 115 break; 116 case SPRN_SPRG2: 117 kvmppc_set_sprg2(vcpu, spr_val); 118 break; 119 case SPRN_SPRG3: 120 kvmppc_set_sprg3(vcpu, spr_val); 121 break; 122 123 /* PIR can legally be written, but we ignore it */ 124 case SPRN_PIR: break; 125 126 default: 127 emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn, 128 spr_val); 129 if (emulated == EMULATE_FAIL) 130 printk(KERN_INFO "mtspr: unknown spr " 131 "0x%x\n", sprn); 132 break; 133 } 134 135 kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS); 136 137 return emulated; 138 } 139 140 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) 141 { 142 enum emulation_result emulated = EMULATE_DONE; 143 ulong spr_val = 0; 144 145 switch (sprn) { 146 case SPRN_SRR0: 147 spr_val = kvmppc_get_srr0(vcpu); 148 break; 149 case SPRN_SRR1: 150 spr_val = kvmppc_get_srr1(vcpu); 151 break; 152 case SPRN_PVR: 153 spr_val = vcpu->arch.pvr; 154 break; 155 case SPRN_PIR: 156 spr_val = vcpu->vcpu_id; 157 break; 158 159 /* Note: mftb and TBRL/TBWL are user-accessible, so 160 * the guest can always access the real TB anyways. 161 * In fact, we probably will never see these traps. */ 162 case SPRN_TBWL: 163 spr_val = get_tb() >> 32; 164 break; 165 case SPRN_TBWU: 166 spr_val = get_tb(); 167 break; 168 169 case SPRN_SPRG0: 170 spr_val = kvmppc_get_sprg0(vcpu); 171 break; 172 case SPRN_SPRG1: 173 spr_val = kvmppc_get_sprg1(vcpu); 174 break; 175 case SPRN_SPRG2: 176 spr_val = kvmppc_get_sprg2(vcpu); 177 break; 178 case SPRN_SPRG3: 179 spr_val = kvmppc_get_sprg3(vcpu); 180 break; 181 /* Note: SPRG4-7 are user-readable, so we don't get 182 * a trap. */ 183 184 case SPRN_DEC: 185 spr_val = kvmppc_get_dec(vcpu, get_tb()); 186 break; 187 default: 188 emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn, 189 &spr_val); 190 if (unlikely(emulated == EMULATE_FAIL)) { 191 printk(KERN_INFO "mfspr: unknown spr " 192 "0x%x\n", sprn); 193 } 194 break; 195 } 196 197 if (emulated == EMULATE_DONE) 198 kvmppc_set_gpr(vcpu, rt, spr_val); 199 kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS); 200 201 return emulated; 202 } 203 204 /* XXX Should probably auto-generate instruction decoding for a particular core 205 * from opcode tables in the future. */ 206 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) 207 { 208 u32 inst; 209 int rs, rt, sprn; 210 enum emulation_result emulated; 211 int advance = 1; 212 213 /* this default type might be overwritten by subcategories */ 214 kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); 215 216 emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); 217 if (emulated != EMULATE_DONE) 218 return emulated; 219 220 pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); 221 222 rs = get_rs(inst); 223 rt = get_rt(inst); 224 sprn = get_sprn(inst); 225 226 switch (get_op(inst)) { 227 case OP_TRAP: 228 #ifdef CONFIG_PPC_BOOK3S 229 case OP_TRAP_64: 230 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 231 #else 232 kvmppc_core_queue_program(vcpu, 233 vcpu->arch.shared->esr | ESR_PTR); 234 #endif 235 advance = 0; 236 break; 237 238 case 31: 239 switch (get_xop(inst)) { 240 241 case OP_31_XOP_TRAP: 242 #ifdef CONFIG_64BIT 243 case OP_31_XOP_TRAP_64: 244 #endif 245 #ifdef CONFIG_PPC_BOOK3S 246 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 247 #else 248 kvmppc_core_queue_program(vcpu, 249 vcpu->arch.shared->esr | ESR_PTR); 250 #endif 251 advance = 0; 252 break; 253 254 case OP_31_XOP_MFSPR: 255 emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt); 256 if (emulated == EMULATE_AGAIN) { 257 emulated = EMULATE_DONE; 258 advance = 0; 259 } 260 break; 261 262 case OP_31_XOP_MTSPR: 263 emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs); 264 if (emulated == EMULATE_AGAIN) { 265 emulated = EMULATE_DONE; 266 advance = 0; 267 } 268 break; 269 270 case OP_31_XOP_TLBSYNC: 271 break; 272 273 default: 274 /* Attempt core-specific emulation below. */ 275 emulated = EMULATE_FAIL; 276 } 277 break; 278 279 case 0: 280 /* 281 * Instruction with primary opcode 0. Based on PowerISA 282 * these are illegal instructions. 283 */ 284 if (inst == KVMPPC_INST_SW_BREAKPOINT) { 285 run->exit_reason = KVM_EXIT_DEBUG; 286 run->debug.arch.address = kvmppc_get_pc(vcpu); 287 emulated = EMULATE_EXIT_USER; 288 advance = 0; 289 } else 290 emulated = EMULATE_FAIL; 291 292 break; 293 294 default: 295 emulated = EMULATE_FAIL; 296 } 297 298 if (emulated == EMULATE_FAIL) { 299 emulated = vcpu->kvm->arch.kvm_ops->emulate_op(run, vcpu, inst, 300 &advance); 301 if (emulated == EMULATE_AGAIN) { 302 advance = 0; 303 } else if (emulated == EMULATE_FAIL) { 304 advance = 0; 305 printk(KERN_ERR "Couldn't emulate instruction 0x%08x " 306 "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst)); 307 } 308 } 309 310 trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated); 311 312 /* Advance past emulated instruction. */ 313 if (advance) 314 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4); 315 316 return emulated; 317 } 318 EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction); 319