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: %x\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 49 /* POWER4+ triggers a dec interrupt if the value is < 0 */ 50 if (vcpu->arch.dec & 0x80000000) { 51 kvmppc_core_queue_dec(vcpu); 52 return; 53 } 54 #endif 55 56 #ifdef CONFIG_BOOKE 57 /* On BOOKE, DEC = 0 is as good as decrementer not enabled */ 58 if (vcpu->arch.dec == 0) 59 return; 60 #endif 61 62 /* 63 * The decrementer ticks at the same rate as the timebase, so 64 * that's how we convert the guest DEC value to the number of 65 * host ticks. 66 */ 67 68 dec_time = vcpu->arch.dec; 69 /* 70 * Guest timebase ticks at the same frequency as host decrementer. 71 * So use the host decrementer calculations for decrementer emulation. 72 */ 73 dec_time = dec_time << decrementer_clockevent.shift; 74 do_div(dec_time, decrementer_clockevent.mult); 75 dec_nsec = do_div(dec_time, NSEC_PER_SEC); 76 hrtimer_start(&vcpu->arch.dec_timer, 77 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL); 78 vcpu->arch.dec_jiffies = get_tb(); 79 } 80 81 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb) 82 { 83 u64 jd = tb - vcpu->arch.dec_jiffies; 84 85 #ifdef CONFIG_BOOKE 86 if (vcpu->arch.dec < jd) 87 return 0; 88 #endif 89 90 return vcpu->arch.dec - jd; 91 } 92 93 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs) 94 { 95 enum emulation_result emulated = EMULATE_DONE; 96 ulong spr_val = kvmppc_get_gpr(vcpu, rs); 97 98 switch (sprn) { 99 case SPRN_SRR0: 100 kvmppc_set_srr0(vcpu, spr_val); 101 break; 102 case SPRN_SRR1: 103 kvmppc_set_srr1(vcpu, spr_val); 104 break; 105 106 /* XXX We need to context-switch the timebase for 107 * watchdog and FIT. */ 108 case SPRN_TBWL: break; 109 case SPRN_TBWU: break; 110 111 case SPRN_DEC: 112 vcpu->arch.dec = spr_val; 113 kvmppc_emulate_dec(vcpu); 114 break; 115 116 case SPRN_SPRG0: 117 kvmppc_set_sprg0(vcpu, spr_val); 118 break; 119 case SPRN_SPRG1: 120 kvmppc_set_sprg1(vcpu, spr_val); 121 break; 122 case SPRN_SPRG2: 123 kvmppc_set_sprg2(vcpu, spr_val); 124 break; 125 case SPRN_SPRG3: 126 kvmppc_set_sprg3(vcpu, spr_val); 127 break; 128 129 /* PIR can legally be written, but we ignore it */ 130 case SPRN_PIR: break; 131 132 default: 133 emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn, 134 spr_val); 135 if (emulated == EMULATE_FAIL) 136 printk(KERN_INFO "mtspr: unknown spr " 137 "0x%x\n", sprn); 138 break; 139 } 140 141 kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS); 142 143 return emulated; 144 } 145 146 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) 147 { 148 enum emulation_result emulated = EMULATE_DONE; 149 ulong spr_val = 0; 150 151 switch (sprn) { 152 case SPRN_SRR0: 153 spr_val = kvmppc_get_srr0(vcpu); 154 break; 155 case SPRN_SRR1: 156 spr_val = kvmppc_get_srr1(vcpu); 157 break; 158 case SPRN_PVR: 159 spr_val = vcpu->arch.pvr; 160 break; 161 case SPRN_PIR: 162 spr_val = vcpu->vcpu_id; 163 break; 164 165 /* Note: mftb and TBRL/TBWL are user-accessible, so 166 * the guest can always access the real TB anyways. 167 * In fact, we probably will never see these traps. */ 168 case SPRN_TBWL: 169 spr_val = get_tb() >> 32; 170 break; 171 case SPRN_TBWU: 172 spr_val = get_tb(); 173 break; 174 175 case SPRN_SPRG0: 176 spr_val = kvmppc_get_sprg0(vcpu); 177 break; 178 case SPRN_SPRG1: 179 spr_val = kvmppc_get_sprg1(vcpu); 180 break; 181 case SPRN_SPRG2: 182 spr_val = kvmppc_get_sprg2(vcpu); 183 break; 184 case SPRN_SPRG3: 185 spr_val = kvmppc_get_sprg3(vcpu); 186 break; 187 /* Note: SPRG4-7 are user-readable, so we don't get 188 * a trap. */ 189 190 case SPRN_DEC: 191 spr_val = kvmppc_get_dec(vcpu, get_tb()); 192 break; 193 default: 194 emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn, 195 &spr_val); 196 if (unlikely(emulated == EMULATE_FAIL)) { 197 printk(KERN_INFO "mfspr: unknown spr " 198 "0x%x\n", sprn); 199 } 200 break; 201 } 202 203 if (emulated == EMULATE_DONE) 204 kvmppc_set_gpr(vcpu, rt, spr_val); 205 kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS); 206 207 return emulated; 208 } 209 210 /* XXX Should probably auto-generate instruction decoding for a particular core 211 * from opcode tables in the future. */ 212 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) 213 { 214 u32 inst; 215 int rs, rt, sprn; 216 enum emulation_result emulated; 217 int advance = 1; 218 219 /* this default type might be overwritten by subcategories */ 220 kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); 221 222 emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); 223 if (emulated != EMULATE_DONE) 224 return emulated; 225 226 pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); 227 228 rs = get_rs(inst); 229 rt = get_rt(inst); 230 sprn = get_sprn(inst); 231 232 switch (get_op(inst)) { 233 case OP_TRAP: 234 #ifdef CONFIG_PPC_BOOK3S 235 case OP_TRAP_64: 236 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 237 #else 238 kvmppc_core_queue_program(vcpu, 239 vcpu->arch.shared->esr | ESR_PTR); 240 #endif 241 advance = 0; 242 break; 243 244 case 31: 245 switch (get_xop(inst)) { 246 247 case OP_31_XOP_TRAP: 248 #ifdef CONFIG_64BIT 249 case OP_31_XOP_TRAP_64: 250 #endif 251 #ifdef CONFIG_PPC_BOOK3S 252 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP); 253 #else 254 kvmppc_core_queue_program(vcpu, 255 vcpu->arch.shared->esr | ESR_PTR); 256 #endif 257 advance = 0; 258 break; 259 260 case OP_31_XOP_MFSPR: 261 emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt); 262 break; 263 264 case OP_31_XOP_MTSPR: 265 emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs); 266 break; 267 268 case OP_31_XOP_TLBSYNC: 269 break; 270 271 default: 272 /* Attempt core-specific emulation below. */ 273 emulated = EMULATE_FAIL; 274 } 275 break; 276 277 case 0: 278 /* 279 * Instruction with primary opcode 0. Based on PowerISA 280 * these are illegal instructions. 281 */ 282 if (inst == KVMPPC_INST_SW_BREAKPOINT) { 283 run->exit_reason = KVM_EXIT_DEBUG; 284 run->debug.arch.address = kvmppc_get_pc(vcpu); 285 emulated = EMULATE_EXIT_USER; 286 advance = 0; 287 } else 288 emulated = EMULATE_FAIL; 289 290 break; 291 292 default: 293 emulated = EMULATE_FAIL; 294 } 295 296 if (emulated == EMULATE_FAIL) { 297 emulated = vcpu->kvm->arch.kvm_ops->emulate_op(run, vcpu, inst, 298 &advance); 299 if (emulated == EMULATE_AGAIN) { 300 advance = 0; 301 } else if (emulated == EMULATE_FAIL) { 302 advance = 0; 303 printk(KERN_ERR "Couldn't emulate instruction 0x%08x " 304 "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst)); 305 } 306 } 307 308 trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated); 309 310 /* Advance past emulated instruction. */ 311 if (advance) 312 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4); 313 314 return emulated; 315 } 316 EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction); 317