xref: /openbmc/linux/arch/powerpc/kernel/kvm_emul.S (revision 2cf1c348)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *
4 * Copyright SUSE Linux Products GmbH 2010
5 * Copyright 2010-2011 Freescale Semiconductor, Inc.
6 *
7 * Authors: Alexander Graf <agraf@suse.de>
8 */
9
10#include <asm/ppc_asm.h>
11#include <asm/kvm_asm.h>
12#include <asm/reg.h>
13#include <asm/page.h>
14#include <asm/asm-offsets.h>
15#include <asm/asm-compat.h>
16
17#define KVM_MAGIC_PAGE		(-4096)
18
19#ifdef CONFIG_64BIT
20#define LL64(reg, offs, reg2)	ld	reg, (offs)(reg2)
21#define STL64(reg, offs, reg2)	std	reg, (offs)(reg2)
22#else
23#define LL64(reg, offs, reg2)	lwz	reg, (offs + 4)(reg2)
24#define STL64(reg, offs, reg2)	stw	reg, (offs + 4)(reg2)
25#endif
26
27#define SCRATCH_SAVE							\
28	/* Enable critical section. We are critical if			\
29	   shared->critical == r1 */					\
30	STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);		\
31									\
32	/* Save state */						\
33	PPC_STL	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);		\
34	PPC_STL	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);		\
35	mfcr	r31;							\
36	stw	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);
37
38#define SCRATCH_RESTORE							\
39	/* Restore state */						\
40	PPC_LL	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);		\
41	lwz	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);		\
42	mtcr	r30;							\
43	PPC_LL	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);		\
44									\
45	/* Disable critical section. We are critical if			\
46	   shared->critical == r1 and r2 is always != r1 */		\
47	STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);
48
49.global kvm_template_start
50kvm_template_start:
51
52.global kvm_emulate_mtmsrd
53kvm_emulate_mtmsrd:
54
55	SCRATCH_SAVE
56
57	/* Put MSR & ~(MSR_EE|MSR_RI) in r31 */
58	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
59	lis	r30, (~(MSR_EE | MSR_RI))@h
60	ori	r30, r30, (~(MSR_EE | MSR_RI))@l
61	and	r31, r31, r30
62
63	/* OR the register's (MSR_EE|MSR_RI) on MSR */
64kvm_emulate_mtmsrd_reg:
65	ori	r30, r0, 0
66	andi.	r30, r30, (MSR_EE|MSR_RI)
67	or	r31, r31, r30
68
69	/* Put MSR back into magic page */
70	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
71
72	/* Check if we have to fetch an interrupt */
73	lwz	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
74	cmpwi	r31, 0
75	beq+	no_check
76
77	/* Check if we may trigger an interrupt */
78	andi.	r30, r30, MSR_EE
79	beq	no_check
80
81	SCRATCH_RESTORE
82
83	/* Nag hypervisor */
84kvm_emulate_mtmsrd_orig_ins:
85	tlbsync
86
87	b	kvm_emulate_mtmsrd_branch
88
89no_check:
90
91	SCRATCH_RESTORE
92
93	/* Go back to caller */
94kvm_emulate_mtmsrd_branch:
95	b	.
96kvm_emulate_mtmsrd_end:
97
98.global kvm_emulate_mtmsrd_branch_offs
99kvm_emulate_mtmsrd_branch_offs:
100	.long (kvm_emulate_mtmsrd_branch - kvm_emulate_mtmsrd) / 4
101
102.global kvm_emulate_mtmsrd_reg_offs
103kvm_emulate_mtmsrd_reg_offs:
104	.long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4
105
106.global kvm_emulate_mtmsrd_orig_ins_offs
107kvm_emulate_mtmsrd_orig_ins_offs:
108	.long (kvm_emulate_mtmsrd_orig_ins - kvm_emulate_mtmsrd) / 4
109
110.global kvm_emulate_mtmsrd_len
111kvm_emulate_mtmsrd_len:
112	.long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4
113
114
115#define MSR_SAFE_BITS (MSR_EE | MSR_RI)
116#define MSR_CRITICAL_BITS ~MSR_SAFE_BITS
117
118.global kvm_emulate_mtmsr
119kvm_emulate_mtmsr:
120
121	SCRATCH_SAVE
122
123	/* Fetch old MSR in r31 */
124	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
125
126	/* Find the changed bits between old and new MSR */
127kvm_emulate_mtmsr_reg1:
128	ori	r30, r0, 0
129	xor	r31, r30, r31
130
131	/* Check if we need to really do mtmsr */
132	LOAD_REG_IMMEDIATE(r30, MSR_CRITICAL_BITS)
133	and.	r31, r31, r30
134
135	/* No critical bits changed? Maybe we can stay in the guest. */
136	beq	maybe_stay_in_guest
137
138do_mtmsr:
139
140	SCRATCH_RESTORE
141
142	/* Just fire off the mtmsr if it's critical */
143kvm_emulate_mtmsr_orig_ins:
144	mtmsr	r0
145
146	b	kvm_emulate_mtmsr_branch
147
148maybe_stay_in_guest:
149
150	/* Get the target register in r30 */
151kvm_emulate_mtmsr_reg2:
152	ori	r30, r0, 0
153
154	/* Put MSR into magic page because we don't call mtmsr */
155	STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
156
157	/* Check if we have to fetch an interrupt */
158	lwz	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
159	cmpwi	r31, 0
160	beq+	no_mtmsr
161
162	/* Check if we may trigger an interrupt */
163	andi.	r31, r30, MSR_EE
164	bne	do_mtmsr
165
166no_mtmsr:
167
168	SCRATCH_RESTORE
169
170	/* Go back to caller */
171kvm_emulate_mtmsr_branch:
172	b	.
173kvm_emulate_mtmsr_end:
174
175.global kvm_emulate_mtmsr_branch_offs
176kvm_emulate_mtmsr_branch_offs:
177	.long (kvm_emulate_mtmsr_branch - kvm_emulate_mtmsr) / 4
178
179.global kvm_emulate_mtmsr_reg1_offs
180kvm_emulate_mtmsr_reg1_offs:
181	.long (kvm_emulate_mtmsr_reg1 - kvm_emulate_mtmsr) / 4
182
183.global kvm_emulate_mtmsr_reg2_offs
184kvm_emulate_mtmsr_reg2_offs:
185	.long (kvm_emulate_mtmsr_reg2 - kvm_emulate_mtmsr) / 4
186
187.global kvm_emulate_mtmsr_orig_ins_offs
188kvm_emulate_mtmsr_orig_ins_offs:
189	.long (kvm_emulate_mtmsr_orig_ins - kvm_emulate_mtmsr) / 4
190
191.global kvm_emulate_mtmsr_len
192kvm_emulate_mtmsr_len:
193	.long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4
194
195#ifdef CONFIG_BOOKE
196
197/* also used for wrteei 1 */
198.global kvm_emulate_wrtee
199kvm_emulate_wrtee:
200
201	SCRATCH_SAVE
202
203	/* Fetch old MSR in r31 */
204	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
205
206	/* Insert new MSR[EE] */
207kvm_emulate_wrtee_reg:
208	ori	r30, r0, 0
209	rlwimi	r31, r30, 0, MSR_EE
210
211	/*
212	 * If MSR[EE] is now set, check for a pending interrupt.
213	 * We could skip this if MSR[EE] was already on, but that
214	 * should be rare, so don't bother.
215	 */
216	andi.	r30, r30, MSR_EE
217
218	/* Put MSR into magic page because we don't call wrtee */
219	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
220
221	beq	no_wrtee
222
223	/* Check if we have to fetch an interrupt */
224	lwz	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
225	cmpwi	r30, 0
226	bne	do_wrtee
227
228no_wrtee:
229	SCRATCH_RESTORE
230
231	/* Go back to caller */
232kvm_emulate_wrtee_branch:
233	b	.
234
235do_wrtee:
236	SCRATCH_RESTORE
237
238	/* Just fire off the wrtee if it's critical */
239kvm_emulate_wrtee_orig_ins:
240	wrtee	r0
241
242	b	kvm_emulate_wrtee_branch
243
244kvm_emulate_wrtee_end:
245
246.global kvm_emulate_wrtee_branch_offs
247kvm_emulate_wrtee_branch_offs:
248	.long (kvm_emulate_wrtee_branch - kvm_emulate_wrtee) / 4
249
250.global kvm_emulate_wrtee_reg_offs
251kvm_emulate_wrtee_reg_offs:
252	.long (kvm_emulate_wrtee_reg - kvm_emulate_wrtee) / 4
253
254.global kvm_emulate_wrtee_orig_ins_offs
255kvm_emulate_wrtee_orig_ins_offs:
256	.long (kvm_emulate_wrtee_orig_ins - kvm_emulate_wrtee) / 4
257
258.global kvm_emulate_wrtee_len
259kvm_emulate_wrtee_len:
260	.long (kvm_emulate_wrtee_end - kvm_emulate_wrtee) / 4
261
262.global kvm_emulate_wrteei_0
263kvm_emulate_wrteei_0:
264	SCRATCH_SAVE
265
266	/* Fetch old MSR in r31 */
267	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
268
269	/* Remove MSR_EE from old MSR */
270	rlwinm	r31, r31, 0, ~MSR_EE
271
272	/* Write new MSR value back */
273	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
274
275	SCRATCH_RESTORE
276
277	/* Go back to caller */
278kvm_emulate_wrteei_0_branch:
279	b	.
280kvm_emulate_wrteei_0_end:
281
282.global kvm_emulate_wrteei_0_branch_offs
283kvm_emulate_wrteei_0_branch_offs:
284	.long (kvm_emulate_wrteei_0_branch - kvm_emulate_wrteei_0) / 4
285
286.global kvm_emulate_wrteei_0_len
287kvm_emulate_wrteei_0_len:
288	.long (kvm_emulate_wrteei_0_end - kvm_emulate_wrteei_0) / 4
289
290#endif /* CONFIG_BOOKE */
291
292#ifdef CONFIG_PPC_BOOK3S_32
293
294.global kvm_emulate_mtsrin
295kvm_emulate_mtsrin:
296
297	SCRATCH_SAVE
298
299	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
300	andi.	r31, r31, MSR_DR | MSR_IR
301	beq	kvm_emulate_mtsrin_reg1
302
303	SCRATCH_RESTORE
304
305kvm_emulate_mtsrin_orig_ins:
306	nop
307	b	kvm_emulate_mtsrin_branch
308
309kvm_emulate_mtsrin_reg1:
310	/* rX >> 26 */
311	rlwinm  r30,r0,6,26,29
312
313kvm_emulate_mtsrin_reg2:
314	stw	r0, (KVM_MAGIC_PAGE + KVM_MAGIC_SR)(r30)
315
316	SCRATCH_RESTORE
317
318	/* Go back to caller */
319kvm_emulate_mtsrin_branch:
320	b	.
321kvm_emulate_mtsrin_end:
322
323.global kvm_emulate_mtsrin_branch_offs
324kvm_emulate_mtsrin_branch_offs:
325	.long (kvm_emulate_mtsrin_branch - kvm_emulate_mtsrin) / 4
326
327.global kvm_emulate_mtsrin_reg1_offs
328kvm_emulate_mtsrin_reg1_offs:
329	.long (kvm_emulate_mtsrin_reg1 - kvm_emulate_mtsrin) / 4
330
331.global kvm_emulate_mtsrin_reg2_offs
332kvm_emulate_mtsrin_reg2_offs:
333	.long (kvm_emulate_mtsrin_reg2 - kvm_emulate_mtsrin) / 4
334
335.global kvm_emulate_mtsrin_orig_ins_offs
336kvm_emulate_mtsrin_orig_ins_offs:
337	.long (kvm_emulate_mtsrin_orig_ins - kvm_emulate_mtsrin) / 4
338
339.global kvm_emulate_mtsrin_len
340kvm_emulate_mtsrin_len:
341	.long (kvm_emulate_mtsrin_end - kvm_emulate_mtsrin) / 4
342
343#endif /* CONFIG_PPC_BOOK3S_32 */
344
345	.balign 4
346	.global kvm_tmp
347kvm_tmp:
348	.space	(64 * 1024)
349
350.global kvm_tmp_end
351kvm_tmp_end:
352
353.global kvm_template_end
354kvm_template_end:
355