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
kvmppc_emulate_dec(struct kvm_vcpu * vcpu)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
kvmppc_get_dec(struct kvm_vcpu * vcpu,u64 tb)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
kvmppc_emulate_mtspr(struct kvm_vcpu * vcpu,int sprn,int rs)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
kvmppc_emulate_mfspr(struct kvm_vcpu * vcpu,int sprn,int rt)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. */
kvmppc_emulate_instruction(struct kvm_run * run,struct kvm_vcpu * vcpu)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
