Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
[cascardo/linux.git] / arch / powerpc / kvm / book3s_emulate.c
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 SUSE Linux Products GmbH 2009
16  *
17  * Authors: Alexander Graf <agraf@suse.de>
18  */
19
20 #include <asm/kvm_ppc.h>
21 #include <asm/disassemble.h>
22 #include <asm/kvm_book3s.h>
23 #include <asm/reg.h>
24 #include <asm/switch_to.h>
25 #include <asm/time.h>
26
27 #define OP_19_XOP_RFID          18
28 #define OP_19_XOP_RFI           50
29
30 #define OP_31_XOP_MFMSR         83
31 #define OP_31_XOP_MTMSR         146
32 #define OP_31_XOP_MTMSRD        178
33 #define OP_31_XOP_MTSR          210
34 #define OP_31_XOP_MTSRIN        242
35 #define OP_31_XOP_TLBIEL        274
36 #define OP_31_XOP_TLBIE         306
37 /* Opcode is officially reserved, reuse it as sc 1 when sc 1 doesn't trap */
38 #define OP_31_XOP_FAKE_SC1      308
39 #define OP_31_XOP_SLBMTE        402
40 #define OP_31_XOP_SLBIE         434
41 #define OP_31_XOP_SLBIA         498
42 #define OP_31_XOP_MFSR          595
43 #define OP_31_XOP_MFSRIN        659
44 #define OP_31_XOP_DCBA          758
45 #define OP_31_XOP_SLBMFEV       851
46 #define OP_31_XOP_EIOIO         854
47 #define OP_31_XOP_SLBMFEE       915
48
49 /* DCBZ is actually 1014, but we patch it to 1010 so we get a trap */
50 #define OP_31_XOP_DCBZ          1010
51
52 #define OP_LFS                  48
53 #define OP_LFD                  50
54 #define OP_STFS                 52
55 #define OP_STFD                 54
56
57 #define SPRN_GQR0               912
58 #define SPRN_GQR1               913
59 #define SPRN_GQR2               914
60 #define SPRN_GQR3               915
61 #define SPRN_GQR4               916
62 #define SPRN_GQR5               917
63 #define SPRN_GQR6               918
64 #define SPRN_GQR7               919
65
66 /* Book3S_32 defines mfsrin(v) - but that messes up our abstract
67  * function pointers, so let's just disable the define. */
68 #undef mfsrin
69
70 enum priv_level {
71         PRIV_PROBLEM = 0,
72         PRIV_SUPER = 1,
73         PRIV_HYPER = 2,
74 };
75
76 static bool spr_allowed(struct kvm_vcpu *vcpu, enum priv_level level)
77 {
78         /* PAPR VMs only access supervisor SPRs */
79         if (vcpu->arch.papr_enabled && (level > PRIV_SUPER))
80                 return false;
81
82         /* Limit user space to its own small SPR set */
83         if ((vcpu->arch.shared->msr & MSR_PR) && level > PRIV_PROBLEM)
84                 return false;
85
86         return true;
87 }
88
89 int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
90                               unsigned int inst, int *advance)
91 {
92         int emulated = EMULATE_DONE;
93         int rt = get_rt(inst);
94         int rs = get_rs(inst);
95         int ra = get_ra(inst);
96         int rb = get_rb(inst);
97
98         switch (get_op(inst)) {
99         case 19:
100                 switch (get_xop(inst)) {
101                 case OP_19_XOP_RFID:
102                 case OP_19_XOP_RFI:
103                         kvmppc_set_pc(vcpu, vcpu->arch.shared->srr0);
104                         kvmppc_set_msr(vcpu, vcpu->arch.shared->srr1);
105                         *advance = 0;
106                         break;
107
108                 default:
109                         emulated = EMULATE_FAIL;
110                         break;
111                 }
112                 break;
113         case 31:
114                 switch (get_xop(inst)) {
115                 case OP_31_XOP_MFMSR:
116                         kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->msr);
117                         break;
118                 case OP_31_XOP_MTMSRD:
119                 {
120                         ulong rs_val = kvmppc_get_gpr(vcpu, rs);
121                         if (inst & 0x10000) {
122                                 ulong new_msr = vcpu->arch.shared->msr;
123                                 new_msr &= ~(MSR_RI | MSR_EE);
124                                 new_msr |= rs_val & (MSR_RI | MSR_EE);
125                                 vcpu->arch.shared->msr = new_msr;
126                         } else
127                                 kvmppc_set_msr(vcpu, rs_val);
128                         break;
129                 }
130                 case OP_31_XOP_MTMSR:
131                         kvmppc_set_msr(vcpu, kvmppc_get_gpr(vcpu, rs));
132                         break;
133                 case OP_31_XOP_MFSR:
134                 {
135                         int srnum;
136
137                         srnum = kvmppc_get_field(inst, 12 + 32, 15 + 32);
138                         if (vcpu->arch.mmu.mfsrin) {
139                                 u32 sr;
140                                 sr = vcpu->arch.mmu.mfsrin(vcpu, srnum);
141                                 kvmppc_set_gpr(vcpu, rt, sr);
142                         }
143                         break;
144                 }
145                 case OP_31_XOP_MFSRIN:
146                 {
147                         int srnum;
148
149                         srnum = (kvmppc_get_gpr(vcpu, rb) >> 28) & 0xf;
150                         if (vcpu->arch.mmu.mfsrin) {
151                                 u32 sr;
152                                 sr = vcpu->arch.mmu.mfsrin(vcpu, srnum);
153                                 kvmppc_set_gpr(vcpu, rt, sr);
154                         }
155                         break;
156                 }
157                 case OP_31_XOP_MTSR:
158                         vcpu->arch.mmu.mtsrin(vcpu,
159                                 (inst >> 16) & 0xf,
160                                 kvmppc_get_gpr(vcpu, rs));
161                         break;
162                 case OP_31_XOP_MTSRIN:
163                         vcpu->arch.mmu.mtsrin(vcpu,
164                                 (kvmppc_get_gpr(vcpu, rb) >> 28) & 0xf,
165                                 kvmppc_get_gpr(vcpu, rs));
166                         break;
167                 case OP_31_XOP_TLBIE:
168                 case OP_31_XOP_TLBIEL:
169                 {
170                         bool large = (inst & 0x00200000) ? true : false;
171                         ulong addr = kvmppc_get_gpr(vcpu, rb);
172                         vcpu->arch.mmu.tlbie(vcpu, addr, large);
173                         break;
174                 }
175 #ifdef CONFIG_PPC_BOOK3S_64
176                 case OP_31_XOP_FAKE_SC1:
177                 {
178                         /* SC 1 papr hypercalls */
179                         ulong cmd = kvmppc_get_gpr(vcpu, 3);
180                         int i;
181
182                         if ((vcpu->arch.shared->msr & MSR_PR) ||
183                             !vcpu->arch.papr_enabled) {
184                                 emulated = EMULATE_FAIL;
185                                 break;
186                         }
187
188                         if (kvmppc_h_pr(vcpu, cmd) == EMULATE_DONE)
189                                 break;
190
191                         run->papr_hcall.nr = cmd;
192                         for (i = 0; i < 9; ++i) {
193                                 ulong gpr = kvmppc_get_gpr(vcpu, 4 + i);
194                                 run->papr_hcall.args[i] = gpr;
195                         }
196
197                         run->exit_reason = KVM_EXIT_PAPR_HCALL;
198                         vcpu->arch.hcall_needed = 1;
199                         emulated = EMULATE_EXIT_USER;
200                         break;
201                 }
202 #endif
203                 case OP_31_XOP_EIOIO:
204                         break;
205                 case OP_31_XOP_SLBMTE:
206                         if (!vcpu->arch.mmu.slbmte)
207                                 return EMULATE_FAIL;
208
209                         vcpu->arch.mmu.slbmte(vcpu,
210                                         kvmppc_get_gpr(vcpu, rs),
211                                         kvmppc_get_gpr(vcpu, rb));
212                         break;
213                 case OP_31_XOP_SLBIE:
214                         if (!vcpu->arch.mmu.slbie)
215                                 return EMULATE_FAIL;
216
217                         vcpu->arch.mmu.slbie(vcpu,
218                                         kvmppc_get_gpr(vcpu, rb));
219                         break;
220                 case OP_31_XOP_SLBIA:
221                         if (!vcpu->arch.mmu.slbia)
222                                 return EMULATE_FAIL;
223
224                         vcpu->arch.mmu.slbia(vcpu);
225                         break;
226                 case OP_31_XOP_SLBMFEE:
227                         if (!vcpu->arch.mmu.slbmfee) {
228                                 emulated = EMULATE_FAIL;
229                         } else {
230                                 ulong t, rb_val;
231
232                                 rb_val = kvmppc_get_gpr(vcpu, rb);
233                                 t = vcpu->arch.mmu.slbmfee(vcpu, rb_val);
234                                 kvmppc_set_gpr(vcpu, rt, t);
235                         }
236                         break;
237                 case OP_31_XOP_SLBMFEV:
238                         if (!vcpu->arch.mmu.slbmfev) {
239                                 emulated = EMULATE_FAIL;
240                         } else {
241                                 ulong t, rb_val;
242
243                                 rb_val = kvmppc_get_gpr(vcpu, rb);
244                                 t = vcpu->arch.mmu.slbmfev(vcpu, rb_val);
245                                 kvmppc_set_gpr(vcpu, rt, t);
246                         }
247                         break;
248                 case OP_31_XOP_DCBA:
249                         /* Gets treated as NOP */
250                         break;
251                 case OP_31_XOP_DCBZ:
252                 {
253                         ulong rb_val = kvmppc_get_gpr(vcpu, rb);
254                         ulong ra_val = 0;
255                         ulong addr, vaddr;
256                         u32 zeros[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
257                         u32 dsisr;
258                         int r;
259
260                         if (ra)
261                                 ra_val = kvmppc_get_gpr(vcpu, ra);
262
263                         addr = (ra_val + rb_val) & ~31ULL;
264                         if (!(vcpu->arch.shared->msr & MSR_SF))
265                                 addr &= 0xffffffff;
266                         vaddr = addr;
267
268                         r = kvmppc_st(vcpu, &addr, 32, zeros, true);
269                         if ((r == -ENOENT) || (r == -EPERM)) {
270                                 *advance = 0;
271                                 vcpu->arch.shared->dar = vaddr;
272                                 vcpu->arch.fault_dar = vaddr;
273
274                                 dsisr = DSISR_ISSTORE;
275                                 if (r == -ENOENT)
276                                         dsisr |= DSISR_NOHPTE;
277                                 else if (r == -EPERM)
278                                         dsisr |= DSISR_PROTFAULT;
279
280                                 vcpu->arch.shared->dsisr = dsisr;
281                                 vcpu->arch.fault_dsisr = dsisr;
282
283                                 kvmppc_book3s_queue_irqprio(vcpu,
284                                         BOOK3S_INTERRUPT_DATA_STORAGE);
285                         }
286
287                         break;
288                 }
289                 default:
290                         emulated = EMULATE_FAIL;
291                 }
292                 break;
293         default:
294                 emulated = EMULATE_FAIL;
295         }
296
297         if (emulated == EMULATE_FAIL)
298                 emulated = kvmppc_emulate_paired_single(run, vcpu);
299
300         return emulated;
301 }
302
303 void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat, bool upper,
304                     u32 val)
305 {
306         if (upper) {
307                 /* Upper BAT */
308                 u32 bl = (val >> 2) & 0x7ff;
309                 bat->bepi_mask = (~bl << 17);
310                 bat->bepi = val & 0xfffe0000;
311                 bat->vs = (val & 2) ? 1 : 0;
312                 bat->vp = (val & 1) ? 1 : 0;
313                 bat->raw = (bat->raw & 0xffffffff00000000ULL) | val;
314         } else {
315                 /* Lower BAT */
316                 bat->brpn = val & 0xfffe0000;
317                 bat->wimg = (val >> 3) & 0xf;
318                 bat->pp = val & 3;
319                 bat->raw = (bat->raw & 0x00000000ffffffffULL) | ((u64)val << 32);
320         }
321 }
322
323 static struct kvmppc_bat *kvmppc_find_bat(struct kvm_vcpu *vcpu, int sprn)
324 {
325         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
326         struct kvmppc_bat *bat;
327
328         switch (sprn) {
329         case SPRN_IBAT0U ... SPRN_IBAT3L:
330                 bat = &vcpu_book3s->ibat[(sprn - SPRN_IBAT0U) / 2];
331                 break;
332         case SPRN_IBAT4U ... SPRN_IBAT7L:
333                 bat = &vcpu_book3s->ibat[4 + ((sprn - SPRN_IBAT4U) / 2)];
334                 break;
335         case SPRN_DBAT0U ... SPRN_DBAT3L:
336                 bat = &vcpu_book3s->dbat[(sprn - SPRN_DBAT0U) / 2];
337                 break;
338         case SPRN_DBAT4U ... SPRN_DBAT7L:
339                 bat = &vcpu_book3s->dbat[4 + ((sprn - SPRN_DBAT4U) / 2)];
340                 break;
341         default:
342                 BUG();
343         }
344
345         return bat;
346 }
347
348 int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
349 {
350         int emulated = EMULATE_DONE;
351
352         switch (sprn) {
353         case SPRN_SDR1:
354                 if (!spr_allowed(vcpu, PRIV_HYPER))
355                         goto unprivileged;
356                 to_book3s(vcpu)->sdr1 = spr_val;
357                 break;
358         case SPRN_DSISR:
359                 vcpu->arch.shared->dsisr = spr_val;
360                 break;
361         case SPRN_DAR:
362                 vcpu->arch.shared->dar = spr_val;
363                 break;
364         case SPRN_HIOR:
365                 to_book3s(vcpu)->hior = spr_val;
366                 break;
367         case SPRN_IBAT0U ... SPRN_IBAT3L:
368         case SPRN_IBAT4U ... SPRN_IBAT7L:
369         case SPRN_DBAT0U ... SPRN_DBAT3L:
370         case SPRN_DBAT4U ... SPRN_DBAT7L:
371         {
372                 struct kvmppc_bat *bat = kvmppc_find_bat(vcpu, sprn);
373
374                 kvmppc_set_bat(vcpu, bat, !(sprn % 2), (u32)spr_val);
375                 /* BAT writes happen so rarely that we're ok to flush
376                  * everything here */
377                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
378                 kvmppc_mmu_flush_segments(vcpu);
379                 break;
380         }
381         case SPRN_HID0:
382                 to_book3s(vcpu)->hid[0] = spr_val;
383                 break;
384         case SPRN_HID1:
385                 to_book3s(vcpu)->hid[1] = spr_val;
386                 break;
387         case SPRN_HID2:
388                 to_book3s(vcpu)->hid[2] = spr_val;
389                 break;
390         case SPRN_HID2_GEKKO:
391                 to_book3s(vcpu)->hid[2] = spr_val;
392                 /* HID2.PSE controls paired single on gekko */
393                 switch (vcpu->arch.pvr) {
394                 case 0x00080200:        /* lonestar 2.0 */
395                 case 0x00088202:        /* lonestar 2.2 */
396                 case 0x70000100:        /* gekko 1.0 */
397                 case 0x00080100:        /* gekko 2.0 */
398                 case 0x00083203:        /* gekko 2.3a */
399                 case 0x00083213:        /* gekko 2.3b */
400                 case 0x00083204:        /* gekko 2.4 */
401                 case 0x00083214:        /* gekko 2.4e (8SE) - retail HW2 */
402                 case 0x00087200:        /* broadway */
403                         if (vcpu->arch.hflags & BOOK3S_HFLAG_NATIVE_PS) {
404                                 /* Native paired singles */
405                         } else if (spr_val & (1 << 29)) { /* HID2.PSE */
406                                 vcpu->arch.hflags |= BOOK3S_HFLAG_PAIRED_SINGLE;
407                                 kvmppc_giveup_ext(vcpu, MSR_FP);
408                         } else {
409                                 vcpu->arch.hflags &= ~BOOK3S_HFLAG_PAIRED_SINGLE;
410                         }
411                         break;
412                 }
413                 break;
414         case SPRN_HID4:
415         case SPRN_HID4_GEKKO:
416                 to_book3s(vcpu)->hid[4] = spr_val;
417                 break;
418         case SPRN_HID5:
419                 to_book3s(vcpu)->hid[5] = spr_val;
420                 /* guest HID5 set can change is_dcbz32 */
421                 if (vcpu->arch.mmu.is_dcbz32(vcpu) &&
422                     (mfmsr() & MSR_HV))
423                         vcpu->arch.hflags |= BOOK3S_HFLAG_DCBZ32;
424                 break;
425         case SPRN_PURR:
426                 to_book3s(vcpu)->purr_offset = spr_val - get_tb();
427                 break;
428         case SPRN_SPURR:
429                 to_book3s(vcpu)->spurr_offset = spr_val - get_tb();
430                 break;
431         case SPRN_GQR0:
432         case SPRN_GQR1:
433         case SPRN_GQR2:
434         case SPRN_GQR3:
435         case SPRN_GQR4:
436         case SPRN_GQR5:
437         case SPRN_GQR6:
438         case SPRN_GQR7:
439                 to_book3s(vcpu)->gqr[sprn - SPRN_GQR0] = spr_val;
440                 break;
441         case SPRN_ICTC:
442         case SPRN_THRM1:
443         case SPRN_THRM2:
444         case SPRN_THRM3:
445         case SPRN_CTRLF:
446         case SPRN_CTRLT:
447         case SPRN_L2CR:
448         case SPRN_DSCR:
449         case SPRN_MMCR0_GEKKO:
450         case SPRN_MMCR1_GEKKO:
451         case SPRN_PMC1_GEKKO:
452         case SPRN_PMC2_GEKKO:
453         case SPRN_PMC3_GEKKO:
454         case SPRN_PMC4_GEKKO:
455         case SPRN_WPAR_GEKKO:
456         case SPRN_MSSSR0:
457         case SPRN_DABR:
458                 break;
459 unprivileged:
460         default:
461                 printk(KERN_INFO "KVM: invalid SPR write: %d\n", sprn);
462 #ifndef DEBUG_SPR
463                 emulated = EMULATE_FAIL;
464 #endif
465                 break;
466         }
467
468         return emulated;
469 }
470
471 int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val)
472 {
473         int emulated = EMULATE_DONE;
474
475         switch (sprn) {
476         case SPRN_IBAT0U ... SPRN_IBAT3L:
477         case SPRN_IBAT4U ... SPRN_IBAT7L:
478         case SPRN_DBAT0U ... SPRN_DBAT3L:
479         case SPRN_DBAT4U ... SPRN_DBAT7L:
480         {
481                 struct kvmppc_bat *bat = kvmppc_find_bat(vcpu, sprn);
482
483                 if (sprn % 2)
484                         *spr_val = bat->raw >> 32;
485                 else
486                         *spr_val = bat->raw;
487
488                 break;
489         }
490         case SPRN_SDR1:
491                 if (!spr_allowed(vcpu, PRIV_HYPER))
492                         goto unprivileged;
493                 *spr_val = to_book3s(vcpu)->sdr1;
494                 break;
495         case SPRN_DSISR:
496                 *spr_val = vcpu->arch.shared->dsisr;
497                 break;
498         case SPRN_DAR:
499                 *spr_val = vcpu->arch.shared->dar;
500                 break;
501         case SPRN_HIOR:
502                 *spr_val = to_book3s(vcpu)->hior;
503                 break;
504         case SPRN_HID0:
505                 *spr_val = to_book3s(vcpu)->hid[0];
506                 break;
507         case SPRN_HID1:
508                 *spr_val = to_book3s(vcpu)->hid[1];
509                 break;
510         case SPRN_HID2:
511         case SPRN_HID2_GEKKO:
512                 *spr_val = to_book3s(vcpu)->hid[2];
513                 break;
514         case SPRN_HID4:
515         case SPRN_HID4_GEKKO:
516                 *spr_val = to_book3s(vcpu)->hid[4];
517                 break;
518         case SPRN_HID5:
519                 *spr_val = to_book3s(vcpu)->hid[5];
520                 break;
521         case SPRN_CFAR:
522         case SPRN_DSCR:
523                 *spr_val = 0;
524                 break;
525         case SPRN_PURR:
526                 *spr_val = get_tb() + to_book3s(vcpu)->purr_offset;
527                 break;
528         case SPRN_SPURR:
529                 *spr_val = get_tb() + to_book3s(vcpu)->purr_offset;
530                 break;
531         case SPRN_GQR0:
532         case SPRN_GQR1:
533         case SPRN_GQR2:
534         case SPRN_GQR3:
535         case SPRN_GQR4:
536         case SPRN_GQR5:
537         case SPRN_GQR6:
538         case SPRN_GQR7:
539                 *spr_val = to_book3s(vcpu)->gqr[sprn - SPRN_GQR0];
540                 break;
541         case SPRN_THRM1:
542         case SPRN_THRM2:
543         case SPRN_THRM3:
544         case SPRN_CTRLF:
545         case SPRN_CTRLT:
546         case SPRN_L2CR:
547         case SPRN_MMCR0_GEKKO:
548         case SPRN_MMCR1_GEKKO:
549         case SPRN_PMC1_GEKKO:
550         case SPRN_PMC2_GEKKO:
551         case SPRN_PMC3_GEKKO:
552         case SPRN_PMC4_GEKKO:
553         case SPRN_WPAR_GEKKO:
554         case SPRN_MSSSR0:
555         case SPRN_DABR:
556                 *spr_val = 0;
557                 break;
558         default:
559 unprivileged:
560                 printk(KERN_INFO "KVM: invalid SPR read: %d\n", sprn);
561 #ifndef DEBUG_SPR
562                 emulated = EMULATE_FAIL;
563 #endif
564                 break;
565         }
566
567         return emulated;
568 }
569
570 u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst)
571 {
572         u32 dsisr = 0;
573
574         /*
575          * This is what the spec says about DSISR bits (not mentioned = 0):
576          *
577          * 12:13                [DS]    Set to bits 30:31
578          * 15:16                [X]     Set to bits 29:30
579          * 17                   [X]     Set to bit 25
580          *                      [D/DS]  Set to bit 5
581          * 18:21                [X]     Set to bits 21:24
582          *                      [D/DS]  Set to bits 1:4
583          * 22:26                        Set to bits 6:10 (RT/RS/FRT/FRS)
584          * 27:31                        Set to bits 11:15 (RA)
585          */
586
587         switch (get_op(inst)) {
588         /* D-form */
589         case OP_LFS:
590         case OP_LFD:
591         case OP_STFD:
592         case OP_STFS:
593                 dsisr |= (inst >> 12) & 0x4000; /* bit 17 */
594                 dsisr |= (inst >> 17) & 0x3c00; /* bits 18:21 */
595                 break;
596         /* X-form */
597         case 31:
598                 dsisr |= (inst << 14) & 0x18000; /* bits 15:16 */
599                 dsisr |= (inst << 8)  & 0x04000; /* bit 17 */
600                 dsisr |= (inst << 3)  & 0x03c00; /* bits 18:21 */
601                 break;
602         default:
603                 printk(KERN_INFO "KVM: Unaligned instruction 0x%x\n", inst);
604                 break;
605         }
606
607         dsisr |= (inst >> 16) & 0x03ff; /* bits 22:31 */
608
609         return dsisr;
610 }
611
612 ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
613 {
614         ulong dar = 0;
615         ulong ra = get_ra(inst);
616         ulong rb = get_rb(inst);
617
618         switch (get_op(inst)) {
619         case OP_LFS:
620         case OP_LFD:
621         case OP_STFD:
622         case OP_STFS:
623                 if (ra)
624                         dar = kvmppc_get_gpr(vcpu, ra);
625                 dar += (s32)((s16)inst);
626                 break;
627         case 31:
628                 if (ra)
629                         dar = kvmppc_get_gpr(vcpu, ra);
630                 dar += kvmppc_get_gpr(vcpu, rb);
631                 break;
632         default:
633                 printk(KERN_INFO "KVM: Unaligned instruction 0x%x\n", inst);
634                 break;
635         }
636
637         return dar;
638 }