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 *
17 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
18 */
19
20#include <asm/ppc_asm.h>
21#include <asm/kvm_asm.h>
22#include <asm/reg.h>
23#include <asm/mmu-44x.h>
24#include <asm/page.h>
25#include <asm/asm-offsets.h>
26
27#define KVMPPC_MSR_MASK (MSR_CE|MSR_EE|MSR_PR|MSR_DE|MSR_ME|MSR_IS|MSR_DS)
28
29#define VCPU_GPR(n)     (VCPU_GPRS + (n * 4))
30
31/* The host stack layout: */
32#define HOST_R1         0 /* Implied by stwu. */
33#define HOST_CALLEE_LR  4
34#define HOST_RUN        8
35/* r2 is special: it holds 'current', and it made nonvolatile in the
36 * kernel with the -ffixed-r2 gcc option. */
37#define HOST_R2         12
38#define HOST_NV_GPRS    16
39#define HOST_NV_GPR(n)  (HOST_NV_GPRS + ((n - 14) * 4))
40#define HOST_MIN_STACK_SIZE (HOST_NV_GPR(31) + 4)
41#define HOST_STACK_SIZE (((HOST_MIN_STACK_SIZE + 15) / 16) * 16) /* Align. */
42#define HOST_STACK_LR   (HOST_STACK_SIZE + 4) /* In caller stack frame. */
43
44#define NEED_INST_MASK ((1<<BOOKE_INTERRUPT_PROGRAM) | \
45                        (1<<BOOKE_INTERRUPT_DTLB_MISS))
46
47#define NEED_DEAR_MASK ((1<<BOOKE_INTERRUPT_DATA_STORAGE) | \
48                        (1<<BOOKE_INTERRUPT_DTLB_MISS))
49
50#define NEED_ESR_MASK ((1<<BOOKE_INTERRUPT_DATA_STORAGE) | \
51                       (1<<BOOKE_INTERRUPT_INST_STORAGE) | \
52                       (1<<BOOKE_INTERRUPT_PROGRAM) | \
53                       (1<<BOOKE_INTERRUPT_DTLB_MISS))
54
55.macro KVM_HANDLER ivor_nr
56_GLOBAL(kvmppc_handler_\ivor_nr)
57	/* Get pointer to vcpu and record exit number. */
58	mtspr	SPRN_SPRG0, r4
59	mfspr	r4, SPRN_SPRG1
60	stw	r5, VCPU_GPR(r5)(r4)
61	stw	r6, VCPU_GPR(r6)(r4)
62	mfctr	r5
63	lis	r6, kvmppc_resume_host@h
64	stw	r5, VCPU_CTR(r4)
65	li	r5, \ivor_nr
66	ori	r6, r6, kvmppc_resume_host@l
67	mtctr	r6
68	bctr
69.endm
70
71_GLOBAL(kvmppc_handlers_start)
72KVM_HANDLER BOOKE_INTERRUPT_CRITICAL
73KVM_HANDLER BOOKE_INTERRUPT_MACHINE_CHECK
74KVM_HANDLER BOOKE_INTERRUPT_DATA_STORAGE
75KVM_HANDLER BOOKE_INTERRUPT_INST_STORAGE
76KVM_HANDLER BOOKE_INTERRUPT_EXTERNAL
77KVM_HANDLER BOOKE_INTERRUPT_ALIGNMENT
78KVM_HANDLER BOOKE_INTERRUPT_PROGRAM
79KVM_HANDLER BOOKE_INTERRUPT_FP_UNAVAIL
80KVM_HANDLER BOOKE_INTERRUPT_SYSCALL
81KVM_HANDLER BOOKE_INTERRUPT_AP_UNAVAIL
82KVM_HANDLER BOOKE_INTERRUPT_DECREMENTER
83KVM_HANDLER BOOKE_INTERRUPT_FIT
84KVM_HANDLER BOOKE_INTERRUPT_WATCHDOG
85KVM_HANDLER BOOKE_INTERRUPT_DTLB_MISS
86KVM_HANDLER BOOKE_INTERRUPT_ITLB_MISS
87KVM_HANDLER BOOKE_INTERRUPT_DEBUG
88
89_GLOBAL(kvmppc_handler_len)
90	.long kvmppc_handler_1 - kvmppc_handler_0
91
92
93/* Registers:
94 *  SPRG0: guest r4
95 *  r4: vcpu pointer
96 *  r5: KVM exit number
97 */
98_GLOBAL(kvmppc_resume_host)
99	stw	r3, VCPU_GPR(r3)(r4)
100	mfcr	r3
101	stw	r3, VCPU_CR(r4)
102	stw	r7, VCPU_GPR(r7)(r4)
103	stw	r8, VCPU_GPR(r8)(r4)
104	stw	r9, VCPU_GPR(r9)(r4)
105
106	li	r6, 1
107	slw	r6, r6, r5
108
109	/* Save the faulting instruction and all GPRs for emulation. */
110	andi.	r7, r6, NEED_INST_MASK
111	beq	..skip_inst_copy
112	mfspr	r9, SPRN_SRR0
113	mfmsr	r8
114	ori	r7, r8, MSR_DS
115	mtmsr	r7
116	isync
117	lwz	r9, 0(r9)
118	mtmsr	r8
119	isync
120	stw	r9, VCPU_LAST_INST(r4)
121
122	stw	r15, VCPU_GPR(r15)(r4)
123	stw	r16, VCPU_GPR(r16)(r4)
124	stw	r17, VCPU_GPR(r17)(r4)
125	stw	r18, VCPU_GPR(r18)(r4)
126	stw	r19, VCPU_GPR(r19)(r4)
127	stw	r20, VCPU_GPR(r20)(r4)
128	stw	r21, VCPU_GPR(r21)(r4)
129	stw	r22, VCPU_GPR(r22)(r4)
130	stw	r23, VCPU_GPR(r23)(r4)
131	stw	r24, VCPU_GPR(r24)(r4)
132	stw	r25, VCPU_GPR(r25)(r4)
133	stw	r26, VCPU_GPR(r26)(r4)
134	stw	r27, VCPU_GPR(r27)(r4)
135	stw	r28, VCPU_GPR(r28)(r4)
136	stw	r29, VCPU_GPR(r29)(r4)
137	stw	r30, VCPU_GPR(r30)(r4)
138	stw	r31, VCPU_GPR(r31)(r4)
139..skip_inst_copy:
140
141	/* Also grab DEAR and ESR before the host can clobber them. */
142
143	andi.	r7, r6, NEED_DEAR_MASK
144	beq	..skip_dear
145	mfspr	r9, SPRN_DEAR
146	stw	r9, VCPU_FAULT_DEAR(r4)
147..skip_dear:
148
149	andi.	r7, r6, NEED_ESR_MASK
150	beq	..skip_esr
151	mfspr	r9, SPRN_ESR
152	stw	r9, VCPU_FAULT_ESR(r4)
153..skip_esr:
154
155	/* Save remaining volatile guest register state to vcpu. */
156	stw	r0, VCPU_GPR(r0)(r4)
157	stw	r1, VCPU_GPR(r1)(r4)
158	stw	r2, VCPU_GPR(r2)(r4)
159	stw	r10, VCPU_GPR(r10)(r4)
160	stw	r11, VCPU_GPR(r11)(r4)
161	stw	r12, VCPU_GPR(r12)(r4)
162	stw	r13, VCPU_GPR(r13)(r4)
163	stw	r14, VCPU_GPR(r14)(r4) /* We need a NV GPR below. */
164	mflr	r3
165	stw	r3, VCPU_LR(r4)
166	mfxer	r3
167	stw	r3, VCPU_XER(r4)
168	mfspr	r3, SPRN_SPRG0
169	stw	r3, VCPU_GPR(r4)(r4)
170	mfspr	r3, SPRN_SRR0
171	stw	r3, VCPU_PC(r4)
172
173	/* Restore host stack pointer and PID before IVPR, since the host
174	 * exception handlers use them. */
175	lwz	r1, VCPU_HOST_STACK(r4)
176	lwz	r3, VCPU_HOST_PID(r4)
177	mtspr	SPRN_PID, r3
178
179	/* Restore host IVPR before re-enabling interrupts. We cheat and know
180	 * that Linux IVPR is always 0xc0000000. */
181	lis	r3, 0xc000
182	mtspr	SPRN_IVPR, r3
183
184	/* Switch to kernel stack and jump to handler. */
185	LOAD_REG_ADDR(r3, kvmppc_handle_exit)
186	mtctr	r3
187	lwz	r3, HOST_RUN(r1)
188	lwz	r2, HOST_R2(r1)
189	mr	r14, r4 /* Save vcpu pointer. */
190
191	bctrl	/* kvmppc_handle_exit() */
192
193	/* Restore vcpu pointer and the nonvolatiles we used. */
194	mr	r4, r14
195	lwz	r14, VCPU_GPR(r14)(r4)
196
197	/* Sometimes instruction emulation must restore complete GPR state. */
198	andi.	r5, r3, RESUME_FLAG_NV
199	beq	..skip_nv_load
200	lwz	r15, VCPU_GPR(r15)(r4)
201	lwz	r16, VCPU_GPR(r16)(r4)
202	lwz	r17, VCPU_GPR(r17)(r4)
203	lwz	r18, VCPU_GPR(r18)(r4)
204	lwz	r19, VCPU_GPR(r19)(r4)
205	lwz	r20, VCPU_GPR(r20)(r4)
206	lwz	r21, VCPU_GPR(r21)(r4)
207	lwz	r22, VCPU_GPR(r22)(r4)
208	lwz	r23, VCPU_GPR(r23)(r4)
209	lwz	r24, VCPU_GPR(r24)(r4)
210	lwz	r25, VCPU_GPR(r25)(r4)
211	lwz	r26, VCPU_GPR(r26)(r4)
212	lwz	r27, VCPU_GPR(r27)(r4)
213	lwz	r28, VCPU_GPR(r28)(r4)
214	lwz	r29, VCPU_GPR(r29)(r4)
215	lwz	r30, VCPU_GPR(r30)(r4)
216	lwz	r31, VCPU_GPR(r31)(r4)
217..skip_nv_load:
218
219	/* Should we return to the guest? */
220	andi.	r5, r3, RESUME_FLAG_HOST
221	beq	lightweight_exit
222
223	srawi	r3, r3, 2 /* Shift -ERR back down. */
224
225heavyweight_exit:
226	/* Not returning to guest. */
227
228	/* We already saved guest volatile register state; now save the
229	 * non-volatiles. */
230	stw	r15, VCPU_GPR(r15)(r4)
231	stw	r16, VCPU_GPR(r16)(r4)
232	stw	r17, VCPU_GPR(r17)(r4)
233	stw	r18, VCPU_GPR(r18)(r4)
234	stw	r19, VCPU_GPR(r19)(r4)
235	stw	r20, VCPU_GPR(r20)(r4)
236	stw	r21, VCPU_GPR(r21)(r4)
237	stw	r22, VCPU_GPR(r22)(r4)
238	stw	r23, VCPU_GPR(r23)(r4)
239	stw	r24, VCPU_GPR(r24)(r4)
240	stw	r25, VCPU_GPR(r25)(r4)
241	stw	r26, VCPU_GPR(r26)(r4)
242	stw	r27, VCPU_GPR(r27)(r4)
243	stw	r28, VCPU_GPR(r28)(r4)
244	stw	r29, VCPU_GPR(r29)(r4)
245	stw	r30, VCPU_GPR(r30)(r4)
246	stw	r31, VCPU_GPR(r31)(r4)
247
248	/* Load host non-volatile register state from host stack. */
249	lwz	r14, HOST_NV_GPR(r14)(r1)
250	lwz	r15, HOST_NV_GPR(r15)(r1)
251	lwz	r16, HOST_NV_GPR(r16)(r1)
252	lwz	r17, HOST_NV_GPR(r17)(r1)
253	lwz	r18, HOST_NV_GPR(r18)(r1)
254	lwz	r19, HOST_NV_GPR(r19)(r1)
255	lwz	r20, HOST_NV_GPR(r20)(r1)
256	lwz	r21, HOST_NV_GPR(r21)(r1)
257	lwz	r22, HOST_NV_GPR(r22)(r1)
258	lwz	r23, HOST_NV_GPR(r23)(r1)
259	lwz	r24, HOST_NV_GPR(r24)(r1)
260	lwz	r25, HOST_NV_GPR(r25)(r1)
261	lwz	r26, HOST_NV_GPR(r26)(r1)
262	lwz	r27, HOST_NV_GPR(r27)(r1)
263	lwz	r28, HOST_NV_GPR(r28)(r1)
264	lwz	r29, HOST_NV_GPR(r29)(r1)
265	lwz	r30, HOST_NV_GPR(r30)(r1)
266	lwz	r31, HOST_NV_GPR(r31)(r1)
267
268	/* Return to kvm_vcpu_run(). */
269	lwz	r4, HOST_STACK_LR(r1)
270	addi	r1, r1, HOST_STACK_SIZE
271	mtlr	r4
272	/* r3 still contains the return code from kvmppc_handle_exit(). */
273	blr
274
275
276/* Registers:
277 *  r3: kvm_run pointer
278 *  r4: vcpu pointer
279 */
280_GLOBAL(__kvmppc_vcpu_run)
281	stwu	r1, -HOST_STACK_SIZE(r1)
282	stw	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */
283
284	/* Save host state to stack. */
285	stw	r3, HOST_RUN(r1)
286	mflr	r3
287	stw	r3, HOST_STACK_LR(r1)
288
289	/* Save host non-volatile register state to stack. */
290	stw	r14, HOST_NV_GPR(r14)(r1)
291	stw	r15, HOST_NV_GPR(r15)(r1)
292	stw	r16, HOST_NV_GPR(r16)(r1)
293	stw	r17, HOST_NV_GPR(r17)(r1)
294	stw	r18, HOST_NV_GPR(r18)(r1)
295	stw	r19, HOST_NV_GPR(r19)(r1)
296	stw	r20, HOST_NV_GPR(r20)(r1)
297	stw	r21, HOST_NV_GPR(r21)(r1)
298	stw	r22, HOST_NV_GPR(r22)(r1)
299	stw	r23, HOST_NV_GPR(r23)(r1)
300	stw	r24, HOST_NV_GPR(r24)(r1)
301	stw	r25, HOST_NV_GPR(r25)(r1)
302	stw	r26, HOST_NV_GPR(r26)(r1)
303	stw	r27, HOST_NV_GPR(r27)(r1)
304	stw	r28, HOST_NV_GPR(r28)(r1)
305	stw	r29, HOST_NV_GPR(r29)(r1)
306	stw	r30, HOST_NV_GPR(r30)(r1)
307	stw	r31, HOST_NV_GPR(r31)(r1)
308
309	/* Load guest non-volatiles. */
310	lwz	r14, VCPU_GPR(r14)(r4)
311	lwz	r15, VCPU_GPR(r15)(r4)
312	lwz	r16, VCPU_GPR(r16)(r4)
313	lwz	r17, VCPU_GPR(r17)(r4)
314	lwz	r18, VCPU_GPR(r18)(r4)
315	lwz	r19, VCPU_GPR(r19)(r4)
316	lwz	r20, VCPU_GPR(r20)(r4)
317	lwz	r21, VCPU_GPR(r21)(r4)
318	lwz	r22, VCPU_GPR(r22)(r4)
319	lwz	r23, VCPU_GPR(r23)(r4)
320	lwz	r24, VCPU_GPR(r24)(r4)
321	lwz	r25, VCPU_GPR(r25)(r4)
322	lwz	r26, VCPU_GPR(r26)(r4)
323	lwz	r27, VCPU_GPR(r27)(r4)
324	lwz	r28, VCPU_GPR(r28)(r4)
325	lwz	r29, VCPU_GPR(r29)(r4)
326	lwz	r30, VCPU_GPR(r30)(r4)
327	lwz	r31, VCPU_GPR(r31)(r4)
328
329lightweight_exit:
330	stw	r2, HOST_R2(r1)
331
332	mfspr	r3, SPRN_PID
333	stw	r3, VCPU_HOST_PID(r4)
334	lwz	r3, VCPU_PID(r4)
335	mtspr	SPRN_PID, r3
336
337	/* Prevent all TLB updates. */
338	mfmsr	r5
339	lis	r6, (MSR_EE|MSR_CE|MSR_ME|MSR_DE)@h
340	ori	r6, r6, (MSR_EE|MSR_CE|MSR_ME|MSR_DE)@l
341	andc	r6, r5, r6
342	mtmsr	r6
343
344	/* Save the host's non-pinned TLB mappings, and load the guest mappings
345	 * over them. Leave the host's "pinned" kernel mappings in place. */
346	/* XXX optimization: use generation count to avoid swapping unmodified
347	 * entries. */
348	mfspr	r10, SPRN_MMUCR			/* Save host MMUCR. */
349	lis	r8, tlb_44x_hwater@ha
350	lwz	r8, tlb_44x_hwater@l(r8)
351	addi	r3, r4, VCPU_HOST_TLB - 4
352	addi	r9, r4, VCPU_SHADOW_TLB - 4
353	li	r6, 0
3541:
355	/* Save host entry. */
356	tlbre	r7, r6, PPC44x_TLB_PAGEID
357	mfspr	r5, SPRN_MMUCR
358	stwu	r5, 4(r3)
359	stwu	r7, 4(r3)
360	tlbre	r7, r6, PPC44x_TLB_XLAT
361	stwu	r7, 4(r3)
362	tlbre	r7, r6, PPC44x_TLB_ATTRIB
363	stwu	r7, 4(r3)
364	/* Load guest entry. */
365	lwzu	r7, 4(r9)
366	mtspr	SPRN_MMUCR, r7
367	lwzu	r7, 4(r9)
368	tlbwe	r7, r6, PPC44x_TLB_PAGEID
369	lwzu	r7, 4(r9)
370	tlbwe	r7, r6, PPC44x_TLB_XLAT
371	lwzu	r7, 4(r9)
372	tlbwe	r7, r6, PPC44x_TLB_ATTRIB
373	/* Increment index. */
374	addi	r6, r6, 1
375	cmpw	r6, r8
376	blt	1b
377	mtspr	SPRN_MMUCR, r10			/* Restore host MMUCR. */
378
379	iccci	0, 0 /* XXX hack */
380
381	/* Load some guest volatiles. */
382	lwz	r0, VCPU_GPR(r0)(r4)
383	lwz	r2, VCPU_GPR(r2)(r4)
384	lwz	r9, VCPU_GPR(r9)(r4)
385	lwz	r10, VCPU_GPR(r10)(r4)
386	lwz	r11, VCPU_GPR(r11)(r4)
387	lwz	r12, VCPU_GPR(r12)(r4)
388	lwz	r13, VCPU_GPR(r13)(r4)
389	lwz	r3, VCPU_LR(r4)
390	mtlr	r3
391	lwz	r3, VCPU_XER(r4)
392	mtxer	r3
393
394	/* Switch the IVPR. XXX If we take a TLB miss after this we're screwed,
395	 * so how do we make sure vcpu won't fault? */
396	lis	r8, kvmppc_booke_handlers@ha
397	lwz	r8, kvmppc_booke_handlers@l(r8)
398	mtspr	SPRN_IVPR, r8
399
400	/* Save vcpu pointer for the exception handlers. */
401	mtspr	SPRN_SPRG1, r4
402
403	/* Can't switch the stack pointer until after IVPR is switched,
404	 * because host interrupt handlers would get confused. */
405	lwz	r1, VCPU_GPR(r1)(r4)
406
407	/* XXX handle USPRG0 */
408	/* Host interrupt handlers may have clobbered these guest-readable
409	 * SPRGs, so we need to reload them here with the guest's values. */
410	lwz	r3, VCPU_SPRG4(r4)
411	mtspr	SPRN_SPRG4, r3
412	lwz	r3, VCPU_SPRG5(r4)
413	mtspr	SPRN_SPRG5, r3
414	lwz	r3, VCPU_SPRG6(r4)
415	mtspr	SPRN_SPRG6, r3
416	lwz	r3, VCPU_SPRG7(r4)
417	mtspr	SPRN_SPRG7, r3
418
419	/* Finish loading guest volatiles and jump to guest. */
420	lwz	r3, VCPU_CTR(r4)
421	mtctr	r3
422	lwz	r3, VCPU_CR(r4)
423	mtcr	r3
424	lwz	r5, VCPU_GPR(r5)(r4)
425	lwz	r6, VCPU_GPR(r6)(r4)
426	lwz	r7, VCPU_GPR(r7)(r4)
427	lwz	r8, VCPU_GPR(r8)(r4)
428	lwz	r3, VCPU_PC(r4)
429	mtsrr0	r3
430	lwz	r3, VCPU_MSR(r4)
431	oris	r3, r3, KVMPPC_MSR_MASK@h
432	ori	r3, r3, KVMPPC_MSR_MASK@l
433	mtsrr1	r3
434	lwz	r3, VCPU_GPR(r3)(r4)
435	lwz	r4, VCPU_GPR(r4)(r4)
436	rfi
437