1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *
4 * Copyright SUSE Linux Products GmbH 2010
5 *
6 * Authors: Alexander Graf <agraf@suse.de>
7 */
8
9/* Real mode helpers */
10
11#include <asm/asm-compat.h>
12#include <asm/feature-fixups.h>
13
14#if defined(CONFIG_PPC_BOOK3S_64)
15
16#define GET_SHADOW_VCPU(reg) \
17 mr reg, r13
18
19#elif defined(CONFIG_PPC_BOOK3S_32)
20
21#define GET_SHADOW_VCPU(reg) \
22 tophys(reg, r2); \
23 lwz reg, (THREAD + THREAD_KVM_SVCPU)(reg); \
24 tophys(reg, reg)
25
26#endif
27
28/* Disable for nested KVM */
29#define USE_QUICK_LAST_INST
30
31
32/* Get helper functions for subarch specific functionality */
33
34#if defined(CONFIG_PPC_BOOK3S_64)
35#include "book3s_64_slb.S"
36#elif defined(CONFIG_PPC_BOOK3S_32)
37#include "book3s_32_sr.S"
38#endif
39
40/******************************************************************************
41 * *
42 * Entry code *
43 * *
44 *****************************************************************************/
45
46.global kvmppc_handler_trampoline_enter
47kvmppc_handler_trampoline_enter:
48
49 /* Required state:
50 *
51 * MSR = ~IR|DR
52 * R1 = host R1
53 * R2 = host R2
54 * R4 = guest shadow MSR
55 * R5 = normal host MSR
56 * R6 = current host MSR (EE, IR, DR off)
57 * LR = highmem guest exit code
58 * all other volatile GPRS = free
59 * SVCPU[CR] = guest CR
60 * SVCPU[XER] = guest XER
61 * SVCPU[CTR] = guest CTR
62 * SVCPU[LR] = guest LR
63 */
64
65 /* r3 = shadow vcpu */
66 GET_SHADOW_VCPU(r3)
67
68 /* Save guest exit handler address and MSR */
69 mflr r0
70 PPC_STL r0, HSTATE_VMHANDLER(r3)
71 PPC_STL r5, HSTATE_HOST_MSR(r3)
72
73 /* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
74 PPC_STL r1, HSTATE_HOST_R1(r3)
75 PPC_STL r2, HSTATE_HOST_R2(r3)
76
77 /* Activate guest mode, so faults get handled by KVM */
78 li r11, KVM_GUEST_MODE_GUEST
79 stb r11, HSTATE_IN_GUEST(r3)
80
81 /* Switch to guest segment. This is subarch specific. */
82 LOAD_GUEST_SEGMENTS
83
84#ifdef CONFIG_PPC_BOOK3S_64
85BEGIN_FTR_SECTION
86 /* Save host FSCR */
87 mfspr r8, SPRN_FSCR
88 std r8, HSTATE_HOST_FSCR(r13)
89 /* Set FSCR during guest execution */
90 ld r9, SVCPU_SHADOW_FSCR(r13)
91 mtspr SPRN_FSCR, r9
92END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
93
94 /* Some guests may need to have dcbz set to 32 byte length.
95 *
96 * Usually we ensure that by patching the guest's instructions
97 * to trap on dcbz and emulate it in the hypervisor.
98 *
99 * If we can, we should tell the CPU to use 32 byte dcbz though,
100 * because that's a lot faster.
101 */
102 lbz r0, HSTATE_RESTORE_HID5(r3)
103 cmpwi r0, 0
104 beq no_dcbz32_on
105
106 mfspr r0,SPRN_HID5
107 ori r0, r0, 0x80 /* XXX HID5_dcbz32 = 0x80 */
108 mtspr SPRN_HID5,r0
109no_dcbz32_on:
110
111#endif /* CONFIG_PPC_BOOK3S_64 */
112
113 /* Enter guest */
114
115 PPC_LL r8, SVCPU_CTR(r3)
116 PPC_LL r9, SVCPU_LR(r3)
117 lwz r10, SVCPU_CR(r3)
118 PPC_LL r11, SVCPU_XER(r3)
119
120 mtctr r8
121 mtlr r9
122 mtcr r10
123 mtxer r11
124
125 /* Move SRR0 and SRR1 into the respective regs */
126 PPC_LL r9, SVCPU_PC(r3)
127 /* First clear RI in our current MSR value */
128 li r0, MSR_RI
129 andc r6, r6, r0
130
131 PPC_LL r0, SVCPU_R0(r3)
132 PPC_LL r1, SVCPU_R1(r3)
133 PPC_LL r2, SVCPU_R2(r3)
134 PPC_LL r5, SVCPU_R5(r3)
135 PPC_LL r7, SVCPU_R7(r3)
136 PPC_LL r8, SVCPU_R8(r3)
137 PPC_LL r10, SVCPU_R10(r3)
138 PPC_LL r11, SVCPU_R11(r3)
139 PPC_LL r12, SVCPU_R12(r3)
140 PPC_LL r13, SVCPU_R13(r3)
141
142 MTMSR_EERI(r6)
143 mtsrr0 r9
144 mtsrr1 r4
145
146 PPC_LL r4, SVCPU_R4(r3)
147 PPC_LL r6, SVCPU_R6(r3)
148 PPC_LL r9, SVCPU_R9(r3)
149 PPC_LL r3, (SVCPU_R3)(r3)
150
151 RFI_TO_GUEST
152kvmppc_handler_trampoline_enter_end:
153
154
155
156/******************************************************************************
157 * *
158 * Exit code *
159 * *
160 *****************************************************************************/
161
162.global kvmppc_interrupt_pr
163kvmppc_interrupt_pr:
164 /* 64-bit entry. Register usage at this point:
165 *
166 * SPRG_SCRATCH0 = guest R13
167 * R9 = HSTATE_IN_GUEST
168 * R12 = (guest CR << 32) | exit handler id
169 * R13 = PACA
170 * HSTATE.SCRATCH0 = guest R12
171 * HSTATE.SCRATCH2 = guest R9
172 */
173#ifdef CONFIG_PPC64
174 /* Match 32-bit entry */
175 ld r9,HSTATE_SCRATCH2(r13)
176 rotldi r12, r12, 32 /* Flip R12 halves for stw */
177 stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
178 srdi r12, r12, 32 /* shift trap into low half */
179#endif
180
181.global kvmppc_handler_trampoline_exit
182kvmppc_handler_trampoline_exit:
183 /* Register usage at this point:
184 *
185 * SPRG_SCRATCH0 = guest R13
186 * R12 = exit handler id
187 * R13 = shadow vcpu (32-bit) or PACA (64-bit)
188 * HSTATE.SCRATCH0 = guest R12
189 * HSTATE.SCRATCH1 = guest CR
190 */
191
192 /* Save registers */
193
194 PPC_STL r0, SVCPU_R0(r13)
195 PPC_STL r1, SVCPU_R1(r13)
196 PPC_STL r2, SVCPU_R2(r13)
197 PPC_STL r3, SVCPU_R3(r13)
198 PPC_STL r4, SVCPU_R4(r13)
199 PPC_STL r5, SVCPU_R5(r13)
200 PPC_STL r6, SVCPU_R6(r13)
201 PPC_STL r7, SVCPU_R7(r13)
202 PPC_STL r8, SVCPU_R8(r13)
203 PPC_STL r9, SVCPU_R9(r13)
204 PPC_STL r10, SVCPU_R10(r13)
205 PPC_STL r11, SVCPU_R11(r13)
206
207 /* Restore R1/R2 so we can handle faults */
208 PPC_LL r1, HSTATE_HOST_R1(r13)
209 PPC_LL r2, HSTATE_HOST_R2(r13)
210
211 /* Save guest PC and MSR */
212#ifdef CONFIG_PPC64
213BEGIN_FTR_SECTION
214 andi. r0, r12, 0x2
215 cmpwi cr1, r0, 0
216 beq 1f
217 mfspr r3,SPRN_HSRR0
218 mfspr r4,SPRN_HSRR1
219 andi. r12,r12,0x3ffd
220 b 2f
221END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
222#endif
2231: mfsrr0 r3
224 mfsrr1 r4
2252:
226 PPC_STL r3, SVCPU_PC(r13)
227 PPC_STL r4, SVCPU_SHADOW_SRR1(r13)
228
229 /* Get scratch'ed off registers */
230 GET_SCRATCH0(r9)
231 PPC_LL r8, HSTATE_SCRATCH0(r13)
232 lwz r7, HSTATE_SCRATCH1(r13)
233
234 PPC_STL r9, SVCPU_R13(r13)
235 PPC_STL r8, SVCPU_R12(r13)
236 stw r7, SVCPU_CR(r13)
237
238 /* Save more register state */
239
240 mfxer r5
241 mfdar r6
242 mfdsisr r7
243 mfctr r8
244 mflr r9
245
246 PPC_STL r5, SVCPU_XER(r13)
247 PPC_STL r6, SVCPU_FAULT_DAR(r13)
248 stw r7, SVCPU_FAULT_DSISR(r13)
249 PPC_STL r8, SVCPU_CTR(r13)
250 PPC_STL r9, SVCPU_LR(r13)
251
252 /*
253 * In order for us to easily get the last instruction,
254 * we got the #vmexit at, we exploit the fact that the
255 * virtual layout is still the same here, so we can just
256 * ld from the guest's PC address
257 */
258
259 /* We only load the last instruction when it's safe */
260 cmpwi r12, BOOK3S_INTERRUPT_DATA_STORAGE
261 beq ld_last_inst
262 cmpwi r12, BOOK3S_INTERRUPT_PROGRAM
263 beq ld_last_inst
264 cmpwi r12, BOOK3S_INTERRUPT_SYSCALL
265 beq ld_last_prev_inst
266 cmpwi r12, BOOK3S_INTERRUPT_ALIGNMENT
267 beq- ld_last_inst
268#ifdef CONFIG_PPC64
269BEGIN_FTR_SECTION
270 cmpwi r12, BOOK3S_INTERRUPT_H_EMUL_ASSIST
271 beq- ld_last_inst
272END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
273BEGIN_FTR_SECTION
274 cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
275 beq- ld_last_inst
276END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
277#endif
278
279 b no_ld_last_inst
280
281ld_last_prev_inst:
282 addi r3, r3, -4
283
284ld_last_inst:
285 /* Save off the guest instruction we're at */
286
287 /* In case lwz faults */
288 li r0, KVM_INST_FETCH_FAILED
289
290#ifdef USE_QUICK_LAST_INST
291
292 /* Set guest mode to 'jump over instruction' so if lwz faults
293 * we'll just continue at the next IP. */
294 li r9, KVM_GUEST_MODE_SKIP
295 stb r9, HSTATE_IN_GUEST(r13)
296
297 /* 1) enable paging for data */
298 mfmsr r9
299 ori r11, r9, MSR_DR /* Enable paging for data */
300 mtmsr r11
301 sync
302 /* 2) fetch the instruction */
303 lwz r0, 0(r3)
304 /* 3) disable paging again */
305 mtmsr r9
306 sync
307
308#endif
309 stw r0, SVCPU_LAST_INST(r13)
310
311no_ld_last_inst:
312
313 /* Unset guest mode */
314 li r9, KVM_GUEST_MODE_NONE
315 stb r9, HSTATE_IN_GUEST(r13)
316
317 /* Switch back to host MMU */
318 LOAD_HOST_SEGMENTS
319
320#ifdef CONFIG_PPC_BOOK3S_64
321
322 lbz r5, HSTATE_RESTORE_HID5(r13)
323 cmpwi r5, 0
324 beq no_dcbz32_off
325
326 li r4, 0
327 mfspr r5,SPRN_HID5
328 rldimi r5,r4,6,56
329 mtspr SPRN_HID5,r5
330
331no_dcbz32_off:
332
333BEGIN_FTR_SECTION
334 /* Save guest FSCR on a FAC_UNAVAIL interrupt */
335 cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
336 bne+ no_fscr_save
337 mfspr r7, SPRN_FSCR
338 std r7, SVCPU_SHADOW_FSCR(r13)
339no_fscr_save:
340 /* Restore host FSCR */
341 ld r8, HSTATE_HOST_FSCR(r13)
342 mtspr SPRN_FSCR, r8
343END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
344
345#endif /* CONFIG_PPC_BOOK3S_64 */
346
347 /*
348 * For some interrupts, we need to call the real Linux
349 * handler, so it can do work for us. This has to happen
350 * as if the interrupt arrived from the kernel though,
351 * so let's fake it here where most state is restored.
352 *
353 * Having set up SRR0/1 with the address where we want
354 * to continue with relocation on (potentially in module
355 * space), we either just go straight there with rfi[d],
356 * or we jump to an interrupt handler if there is an
357 * interrupt to be handled first. In the latter case,
358 * the rfi[d] at the end of the interrupt handler will
359 * get us back to where we want to continue.
360 */
361
362 /* Register usage at this point:
363 *
364 * R1 = host R1
365 * R2 = host R2
366 * R10 = raw exit handler id
367 * R12 = exit handler id
368 * R13 = shadow vcpu (32-bit) or PACA (64-bit)
369 * SVCPU.* = guest *
370 *
371 */
372
373 PPC_LL r6, HSTATE_HOST_MSR(r13)
374#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
375 /*
376 * We don't want to change MSR[TS] bits via rfi here.
377 * The actual TM handling logic will be in host with
378 * recovered DR/IR bits after HSTATE_VMHANDLER.
379 * And MSR_TM can be enabled in HOST_MSR so rfid may
380 * not suppress this change and can lead to exception.
381 * Manually set MSR to prevent TS state change here.
382 */
383 mfmsr r7
384 rldicl r7, r7, 64 - MSR_TS_S_LG, 62
385 rldimi r6, r7, MSR_TS_S_LG, 63 - MSR_TS_T_LG
386#endif
387 PPC_LL r8, HSTATE_VMHANDLER(r13)
388
389#ifdef CONFIG_PPC64
390BEGIN_FTR_SECTION
391 beq cr1, 1f
392 mtspr SPRN_HSRR1, r6
393 mtspr SPRN_HSRR0, r8
394END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
395#endif
3961: /* Restore host msr -> SRR1 */
397 mtsrr1 r6
398 /* Load highmem handler address */
399 mtsrr0 r8
400
401 /* RFI into the highmem handler, or jump to interrupt handler */
402 cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
403 beqa BOOK3S_INTERRUPT_EXTERNAL
404 cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
405 beqa BOOK3S_INTERRUPT_DECREMENTER
406 cmpwi r12, BOOK3S_INTERRUPT_PERFMON
407 beqa BOOK3S_INTERRUPT_PERFMON
408 cmpwi r12, BOOK3S_INTERRUPT_DOORBELL
409 beqa BOOK3S_INTERRUPT_DOORBELL
410
411 RFI_TO_KERNEL
412kvmppc_handler_trampoline_exit_end:
413

source code of linux/arch/powerpc/kvm/book3s_segment.S