1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright IBM Corp. 2007
5 * Copyright 2011 Freescale Semiconductor, Inc.
6 *
7 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
8 */
9
10 #include <linux/jiffies.h>
11 #include <linux/hrtimer.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/kvm_host.h>
15 #include <linux/clockchips.h>
16
17 #include <asm/reg.h>
18 #include <asm/time.h>
19 #include <asm/byteorder.h>
20 #include <asm/kvm_ppc.h>
21 #include <asm/disassemble.h>
22 #include <asm/ppc-opcode.h>
23 #include "timing.h"
24 #include "trace.h"
25
26 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
27 {
28 unsigned long dec_nsec;
29 unsigned long long dec_time;
30
31 pr_debug("mtDEC: %lx\n", vcpu->arch.dec);
32 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
33
34 #ifdef CONFIG_PPC_BOOK3S
35 /* mtdec lowers the interrupt line when positive. */
36 kvmppc_core_dequeue_dec(vcpu);
37 #endif
38
39 #ifdef CONFIG_BOOKE
40 /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
41 if (vcpu->arch.dec == 0)
42 return;
43 #endif
44
45 /*
46 * The decrementer ticks at the same rate as the timebase, so
47 * that's how we convert the guest DEC value to the number of
48 * host ticks.
49 */
50
51 dec_time = vcpu->arch.dec;
52 /*
53 * Guest timebase ticks at the same frequency as host timebase.
54 * So use the host timebase calculations for decrementer emulation.
55 */
56 dec_time = tb_to_ns(dec_time);
57 dec_nsec = do_div(dec_time, NSEC_PER_SEC);
58 hrtimer_start(&vcpu->arch.dec_timer,
59 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
60 vcpu->arch.dec_jiffies = get_tb();
61 }
62
63 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
64 {
65 u64 jd = tb - vcpu->arch.dec_jiffies;
66
67 #ifdef CONFIG_BOOKE
68 if (vcpu->arch.dec < jd)
69 return 0;
70 #endif
71
72 return vcpu->arch.dec - jd;
73 }
74
75 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
76 {
77 enum emulation_result emulated = EMULATE_DONE;
78 ulong spr_val = kvmppc_get_gpr(vcpu, rs);
79
80 switch (sprn) {
81 case SPRN_SRR0:
82 kvmppc_set_srr0(vcpu, spr_val);
83 break;
84 case SPRN_SRR1:
85 kvmppc_set_srr1(vcpu, spr_val);
86 break;
87
88 /* XXX We need to context-switch the timebase for
89 * watchdog and FIT. */
90 case SPRN_TBWL: break;
91 case SPRN_TBWU: break;
92
93 case SPRN_DEC:
94 vcpu->arch.dec = (u32) spr_val;
95 kvmppc_emulate_dec(vcpu);
96 break;
97
98 case SPRN_SPRG0:
99 kvmppc_set_sprg0(vcpu, spr_val);
100 break;
101 case SPRN_SPRG1:
102 kvmppc_set_sprg1(vcpu, spr_val);
103 break;
104 case SPRN_SPRG2:
105 kvmppc_set_sprg2(vcpu, spr_val);
106 break;
107 case SPRN_SPRG3:
108 kvmppc_set_sprg3(vcpu, spr_val);
109 break;
110
111 /* PIR can legally be written, but we ignore it */
112 case SPRN_PIR: break;
113
114 default:
115 emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn,
116 spr_val);
117 if (emulated == EMULATE_FAIL)
118 printk(KERN_INFO "mtspr: unknown spr "
119 "0x%x\n", sprn);
120 break;
121 }
122
123 kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
124
125 return emulated;
126 }
127
128 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
129 {
130 enum emulation_result emulated = EMULATE_DONE;
131 ulong spr_val = 0;
132
133 switch (sprn) {
134 case SPRN_SRR0:
135 spr_val = kvmppc_get_srr0(vcpu);
136 break;
137 case SPRN_SRR1:
138 spr_val = kvmppc_get_srr1(vcpu);
139 break;
140 case SPRN_PVR:
141 spr_val = vcpu->arch.pvr;
142 break;
143 case SPRN_PIR:
144 spr_val = vcpu->vcpu_id;
145 break;
146
147 /* Note: mftb and TBRL/TBWL are user-accessible, so
148 * the guest can always access the real TB anyways.
149 * In fact, we probably will never see these traps. */
150 case SPRN_TBWL:
151 spr_val = get_tb() >> 32;
152 break;
153 case SPRN_TBWU:
154 spr_val = get_tb();
155 break;
156
157 case SPRN_SPRG0:
158 spr_val = kvmppc_get_sprg0(vcpu);
159 break;
160 case SPRN_SPRG1:
161 spr_val = kvmppc_get_sprg1(vcpu);
162 break;
163 case SPRN_SPRG2:
164 spr_val = kvmppc_get_sprg2(vcpu);
165 break;
166 case SPRN_SPRG3:
167 spr_val = kvmppc_get_sprg3(vcpu);
168 break;
169 /* Note: SPRG4-7 are user-readable, so we don't get
170 * a trap. */
171
172 case SPRN_DEC:
173 spr_val = kvmppc_get_dec(vcpu, get_tb());
174 break;
175 default:
176 emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn,
177 &spr_val);
178 if (unlikely(emulated == EMULATE_FAIL)) {
179 printk(KERN_INFO "mfspr: unknown spr "
180 "0x%x\n", sprn);
181 }
182 break;
183 }
184
185 if (emulated == EMULATE_DONE)
186 kvmppc_set_gpr(vcpu, rt, spr_val);
187 kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
188
189 return emulated;
190 }
191
192 /* XXX Should probably auto-generate instruction decoding for a particular core
193 * from opcode tables in the future. */
194 int kvmppc_emulate_instruction(struct kvm_vcpu *vcpu)
195 {
196 u32 inst;
197 ppc_inst_t pinst;
198 int rs, rt, sprn;
199 enum emulation_result emulated;
200 int advance = 1;
201
202 /* this default type might be overwritten by subcategories */
203 kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
204
205 emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
206 inst = ppc_inst_val(pinst);
207 if (emulated != EMULATE_DONE)
208 return emulated;
209
210 pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
211
212 rs = get_rs(inst);
213 rt = get_rt(inst);
214 sprn = get_sprn(inst);
215
216 switch (get_op(inst)) {
217 case OP_TRAP:
218 #ifdef CONFIG_PPC_BOOK3S
219 case OP_TRAP_64:
220 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
221 #else
222 kvmppc_core_queue_program(vcpu,
223 vcpu->arch.shared->esr | ESR_PTR);
224 #endif
225 advance = 0;
226 break;
227
228 case 31:
229 switch (get_xop(inst)) {
230
231 case OP_31_XOP_TRAP:
232 #ifdef CONFIG_64BIT
233 case OP_31_XOP_TRAP_64:
234 #endif
235 #ifdef CONFIG_PPC_BOOK3S
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 OP_31_XOP_MFSPR:
245 emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
246 if (emulated == EMULATE_AGAIN) {
247 emulated = EMULATE_DONE;
248 advance = 0;
249 }
250 break;
251
252 case OP_31_XOP_MTSPR:
253 emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
254 if (emulated == EMULATE_AGAIN) {
255 emulated = EMULATE_DONE;
256 advance = 0;
257 }
258 break;
259
260 case OP_31_XOP_TLBSYNC:
261 break;
262
263 default:
264 /* Attempt core-specific emulation below. */
265 emulated = EMULATE_FAIL;
266 }
267 break;
268
269 case 0:
270 /*
271 * Instruction with primary opcode 0. Based on PowerISA
272 * these are illegal instructions.
273 */
274 if (inst == KVMPPC_INST_SW_BREAKPOINT) {
275 vcpu->run->exit_reason = KVM_EXIT_DEBUG;
276 vcpu->run->debug.arch.status = 0;
277 vcpu->run->debug.arch.address = kvmppc_get_pc(vcpu);
278 emulated = EMULATE_EXIT_USER;
279 advance = 0;
280 } else
281 emulated = EMULATE_FAIL;
282
283 break;
284
285 default:
286 emulated = EMULATE_FAIL;
287 }
288
289 if (emulated == EMULATE_FAIL) {
290 emulated = vcpu->kvm->arch.kvm_ops->emulate_op(vcpu, inst,
291 &advance);
292 if (emulated == EMULATE_AGAIN) {
293 advance = 0;
294 } else if (emulated == EMULATE_FAIL) {
295 advance = 0;
296 printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
297 "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
298 }
299 }
300
301 trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
302
303 /* Advance past emulated instruction. */
304 /*
305 * If this ever handles prefixed instructions, the 4
306 * will need to become ppc_inst_len(pinst) instead.
307 */
308 if (advance)
309 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
310
311 return emulated;
312 }
313 EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);
314
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