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