xref: /linux/arch/powerpc/kvm/book3s_interrupts.S (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
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/ppc_asm.h>
21#include <asm/kvm_asm.h>
22#include <asm/reg.h>
23#include <asm/page.h>
24#include <asm/asm-offsets.h>
25#include <asm/exception-64s.h>
26#include <asm/asm-compat.h>
27
28#if defined(CONFIG_PPC_BOOK3S_64)
29#ifdef PPC64_ELF_ABI_v2
30#define FUNC(name) 		name
31#else
32#define FUNC(name) 		GLUE(.,name)
33#endif
34#define GET_SHADOW_VCPU(reg)    addi	reg, r13, PACA_SVCPU
35
36#elif defined(CONFIG_PPC_BOOK3S_32)
37#define FUNC(name)		name
38#define GET_SHADOW_VCPU(reg)	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
39
40#endif /* CONFIG_PPC_BOOK3S_XX */
41
42#define VCPU_LOAD_NVGPRS(vcpu) \
43	PPC_LL	r14, VCPU_GPR(R14)(vcpu); \
44	PPC_LL	r15, VCPU_GPR(R15)(vcpu); \
45	PPC_LL	r16, VCPU_GPR(R16)(vcpu); \
46	PPC_LL	r17, VCPU_GPR(R17)(vcpu); \
47	PPC_LL	r18, VCPU_GPR(R18)(vcpu); \
48	PPC_LL	r19, VCPU_GPR(R19)(vcpu); \
49	PPC_LL	r20, VCPU_GPR(R20)(vcpu); \
50	PPC_LL	r21, VCPU_GPR(R21)(vcpu); \
51	PPC_LL	r22, VCPU_GPR(R22)(vcpu); \
52	PPC_LL	r23, VCPU_GPR(R23)(vcpu); \
53	PPC_LL	r24, VCPU_GPR(R24)(vcpu); \
54	PPC_LL	r25, VCPU_GPR(R25)(vcpu); \
55	PPC_LL	r26, VCPU_GPR(R26)(vcpu); \
56	PPC_LL	r27, VCPU_GPR(R27)(vcpu); \
57	PPC_LL	r28, VCPU_GPR(R28)(vcpu); \
58	PPC_LL	r29, VCPU_GPR(R29)(vcpu); \
59	PPC_LL	r30, VCPU_GPR(R30)(vcpu); \
60	PPC_LL	r31, VCPU_GPR(R31)(vcpu); \
61
62/*****************************************************************************
63 *                                                                           *
64 *     Guest entry / exit code that is in kernel module memory (highmem)     *
65 *                                                                           *
66 ****************************************************************************/
67
68/* Registers:
69 *  r3: kvm_run pointer
70 *  r4: vcpu pointer
71 */
72_GLOBAL(__kvmppc_vcpu_run)
73
74kvm_start_entry:
75	/* Write correct stack frame */
76	mflr	r0
77	PPC_STL	r0,PPC_LR_STKOFF(r1)
78
79	/* Save host state to the stack */
80	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
81
82	/* Save r3 (kvm_run) and r4 (vcpu) */
83	SAVE_2GPRS(3, r1)
84
85	/* Save non-volatile registers (r14 - r31) */
86	SAVE_NVGPRS(r1)
87
88	/* Save CR */
89	mfcr	r14
90	stw	r14, _CCR(r1)
91
92	/* Save LR */
93	PPC_STL	r0, _LINK(r1)
94
95	/* Load non-volatile guest state from the vcpu */
96	VCPU_LOAD_NVGPRS(r4)
97
98kvm_start_lightweight:
99	/* Copy registers into shadow vcpu so we can access them in real mode */
100	mr	r3, r4
101	bl	FUNC(kvmppc_copy_to_svcpu)
102	nop
103	REST_GPR(4, r1)
104
105#ifdef CONFIG_PPC_BOOK3S_64
106	/* Get the dcbz32 flag */
107	PPC_LL	r3, VCPU_HFLAGS(r4)
108	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
109	stb	r3, HSTATE_RESTORE_HID5(r13)
110
111	/* Load up guest SPRG3 value, since it's user readable */
112	lwz	r3, VCPU_SHAREDBE(r4)
113	cmpwi	r3, 0
114	ld	r5, VCPU_SHARED(r4)
115	beq	sprg3_little_endian
116sprg3_big_endian:
117#ifdef __BIG_ENDIAN__
118	ld	r3, VCPU_SHARED_SPRG3(r5)
119#else
120	addi	r5, r5, VCPU_SHARED_SPRG3
121	ldbrx	r3, 0, r5
122#endif
123	b	after_sprg3_load
124sprg3_little_endian:
125#ifdef __LITTLE_ENDIAN__
126	ld	r3, VCPU_SHARED_SPRG3(r5)
127#else
128	addi	r5, r5, VCPU_SHARED_SPRG3
129	ldbrx	r3, 0, r5
130#endif
131
132after_sprg3_load:
133	mtspr	SPRN_SPRG3, r3
134#endif /* CONFIG_PPC_BOOK3S_64 */
135
136	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
137
138	/* Jump to segment patching handler and into our guest */
139	bl	FUNC(kvmppc_entry_trampoline)
140	nop
141
142/*
143 * This is the handler in module memory. It gets jumped at from the
144 * lowmem trampoline code, so it's basically the guest exit code.
145 *
146 */
147
148	/*
149	 * Register usage at this point:
150	 *
151	 * R1       = host R1
152	 * R2       = host R2
153	 * R12      = exit handler id
154	 * R13      = PACA
155	 * SVCPU.*  = guest *
156	 * MSR.EE   = 1
157	 *
158	 */
159
160	PPC_LL	r3, GPR4(r1)		/* vcpu pointer */
161
162	/*
163	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
164	 * the exit handler id to the vcpu and restore it from there later.
165	 */
166	stw	r12, VCPU_TRAP(r3)
167
168	/* Transfer reg values from shadow vcpu back to vcpu struct */
169
170	bl	FUNC(kvmppc_copy_from_svcpu)
171	nop
172
173#ifdef CONFIG_PPC_BOOK3S_64
174	/*
175	 * Reload kernel SPRG3 value.
176	 * No need to save guest value as usermode can't modify SPRG3.
177	 */
178	ld	r3, PACA_SPRG_VDSO(r13)
179	mtspr	SPRN_SPRG_VDSO_WRITE, r3
180#endif /* CONFIG_PPC_BOOK3S_64 */
181
182	/* R7 = vcpu */
183	PPC_LL	r7, GPR4(r1)
184
185	PPC_STL	r14, VCPU_GPR(R14)(r7)
186	PPC_STL	r15, VCPU_GPR(R15)(r7)
187	PPC_STL	r16, VCPU_GPR(R16)(r7)
188	PPC_STL	r17, VCPU_GPR(R17)(r7)
189	PPC_STL	r18, VCPU_GPR(R18)(r7)
190	PPC_STL	r19, VCPU_GPR(R19)(r7)
191	PPC_STL	r20, VCPU_GPR(R20)(r7)
192	PPC_STL	r21, VCPU_GPR(R21)(r7)
193	PPC_STL	r22, VCPU_GPR(R22)(r7)
194	PPC_STL	r23, VCPU_GPR(R23)(r7)
195	PPC_STL	r24, VCPU_GPR(R24)(r7)
196	PPC_STL	r25, VCPU_GPR(R25)(r7)
197	PPC_STL	r26, VCPU_GPR(R26)(r7)
198	PPC_STL	r27, VCPU_GPR(R27)(r7)
199	PPC_STL	r28, VCPU_GPR(R28)(r7)
200	PPC_STL	r29, VCPU_GPR(R29)(r7)
201	PPC_STL	r30, VCPU_GPR(R30)(r7)
202	PPC_STL	r31, VCPU_GPR(R31)(r7)
203
204	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
205	lwz	r5, VCPU_TRAP(r7)
206
207	/* Restore r3 (kvm_run) and r4 (vcpu) */
208	REST_2GPRS(3, r1)
209	bl	FUNC(kvmppc_handle_exit_pr)
210
211	/* If RESUME_GUEST, get back in the loop */
212	cmpwi	r3, RESUME_GUEST
213	beq	kvm_loop_lightweight
214
215	cmpwi	r3, RESUME_GUEST_NV
216	beq	kvm_loop_heavyweight
217
218kvm_exit_loop:
219
220	PPC_LL	r4, _LINK(r1)
221	mtlr	r4
222
223	lwz	r14, _CCR(r1)
224	mtcr	r14
225
226	/* Restore non-volatile host registers (r14 - r31) */
227	REST_NVGPRS(r1)
228
229	addi    r1, r1, SWITCH_FRAME_SIZE
230	blr
231
232kvm_loop_heavyweight:
233
234	PPC_LL	r4, _LINK(r1)
235	PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
236
237	/* Load vcpu and cpu_run */
238	REST_2GPRS(3, r1)
239
240	/* Load non-volatile guest state from the vcpu */
241	VCPU_LOAD_NVGPRS(r4)
242
243	/* Jump back into the beginning of this function */
244	b	kvm_start_lightweight
245
246kvm_loop_lightweight:
247
248	/* We'll need the vcpu pointer */
249	REST_GPR(4, r1)
250
251	/* Jump back into the beginning of this function */
252	b	kvm_start_lightweight
253