summaryrefslogtreecommitdiffstats
path: root/qemu/pc-bios/optionrom/kvmvapic.S
blob: aa17a402df2ee2ce23a97984007dadd244b9a4c9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
#
# Local APIC acceleration for Windows XP and related guests
#
# Copyright 2011 Red Hat, Inc. and/or its affiliates
#
# Author: Avi Kivity <avi@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2, or (at your
# option) any later version.  See the COPYING file in the top-level directory.
#

#include "optionrom.h"

OPTION_ROM_START

	# clear vapic area: firmware load using rep insb may cause
	# stale tpr/isr/irr data to corrupt the vapic area.
	push %es
	push %cs
	pop %es
	xor %ax, %ax
	mov $vapic_size/2, %cx
	lea vapic, %di
	cld
	rep stosw
	pop %es

	# announce presence to the hypervisor
	mov $vapic_base, %ax
	out %ax, $0x7e

	lret

	.code32
vapic_size = 2*4096

.macro fixup delta=-4
777:
	.text 1
	.long 777b + \delta  - vapic_base
	.text 0
.endm

.macro reenable_vtpr
	out %al, $0x7e
.endm

.text 1
	fixup_start = .
.text 0

.align 16

vapic_base:
	.ascii "kvm aPiC"

	/* relocation data */
	.long vapic_base	; fixup
	.long fixup_start	; fixup
	.long fixup_end		; fixup

	.long vapic		; fixup
	.long vapic_size
vcpu_shift:
	.long 0
real_tpr:
	.long 0
	.long up_set_tpr	; fixup
	.long up_set_tpr_eax	; fixup
	.long up_get_tpr_eax	; fixup
	.long up_get_tpr_ecx	; fixup
	.long up_get_tpr_edx	; fixup
	.long up_get_tpr_ebx	; fixup
	.long 0 /* esp. won't work. */
	.long up_get_tpr_ebp	; fixup
	.long up_get_tpr_esi	; fixup
	.long up_get_tpr_edi	; fixup
	.long up_get_tpr_stack  ; fixup
	.long mp_set_tpr	; fixup
	.long mp_set_tpr_eax	; fixup
	.long mp_get_tpr_eax	; fixup
	.long mp_get_tpr_ecx	; fixup
	.long mp_get_tpr_edx	; fixup
	.long mp_get_tpr_ebx	; fixup
	.long 0 /* esp. won't work. */
	.long mp_get_tpr_ebp	; fixup
	.long mp_get_tpr_esi	; fixup
	.long mp_get_tpr_edi	; fixup
	.long mp_get_tpr_stack  ; fixup

.macro kvm_hypercall
	.byte 0x0f, 0x01, 0xc1
.endm

kvm_hypercall_vapic_poll_irq = 1

pcr_cpu = 0x51

.align 64

mp_get_tpr_eax:
	pushf
	cli
	reenable_vtpr
	push %ecx

	fs/movzbl pcr_cpu, %eax

	mov vcpu_shift, %ecx	; fixup
	shl %cl, %eax
	testb $1, vapic+4(%eax)	; fixup delta=-5
	jz mp_get_tpr_bad
	movzbl vapic(%eax), %eax ; fixup

mp_get_tpr_out:
	pop %ecx
	popf
	ret

mp_get_tpr_bad:
	mov real_tpr, %eax	; fixup
	mov (%eax), %eax
	jmp mp_get_tpr_out

mp_get_tpr_ebx:
	mov %eax, %ebx
	call mp_get_tpr_eax
	xchg %eax, %ebx
	ret

mp_get_tpr_ecx:
	mov %eax, %ecx
	call mp_get_tpr_eax
	xchg %eax, %ecx
	ret

mp_get_tpr_edx:
	mov %eax, %edx
	call mp_get_tpr_eax
	xchg %eax, %edx
	ret

mp_get_tpr_esi:
	mov %eax, %esi
	call mp_get_tpr_eax
	xchg %eax, %esi
	ret

mp_get_tpr_edi:
	mov %eax, %edi
	call mp_get_tpr_edi
	xchg %eax, %edi
	ret

mp_get_tpr_ebp:
	mov %eax, %ebp
	call mp_get_tpr_eax
	xchg %eax, %ebp
	ret

mp_get_tpr_stack:
	call mp_get_tpr_eax
	xchg %eax, 4(%esp)
	ret

mp_set_tpr_eax:
	push %eax
	call mp_set_tpr
	ret

mp_set_tpr:
	pushf
	push %eax
	push %ecx
	push %edx
	push %ebx
	cli
	reenable_vtpr

mp_set_tpr_failed:
	fs/movzbl pcr_cpu, %edx

	mov vcpu_shift, %ecx	; fixup
	shl %cl, %edx

	testb $1, vapic+4(%edx)	; fixup delta=-5
	jz mp_set_tpr_bad

	mov vapic(%edx), %eax	; fixup

	mov %eax, %ebx
	mov 24(%esp), %bl

	/* %ebx = new vapic (%bl = tpr, %bh = isr, %b3 = irr) */

	lock cmpxchg %ebx, vapic(%edx) ; fixup
	jnz mp_set_tpr_failed

	/* compute ppr */
	cmp %bh, %bl
	jae mp_tpr_is_bigger
mp_isr_is_bigger:
	mov %bh, %bl
mp_tpr_is_bigger:
	/* %bl = ppr */
	rol $8, %ebx
	/* now: %bl = irr, %bh = ppr */
	cmp %bh, %bl
	ja mp_set_tpr_poll_irq

mp_set_tpr_out:
	pop %ebx
	pop %edx
	pop %ecx
	pop %eax
	popf
	ret $4

mp_set_tpr_poll_irq:
	mov $kvm_hypercall_vapic_poll_irq, %eax
	kvm_hypercall
	jmp mp_set_tpr_out

mp_set_tpr_bad:
	mov 24(%esp), %ecx
	mov real_tpr, %eax	; fixup
	mov %ecx, (%eax)
	jmp mp_set_tpr_out

up_get_tpr_eax:
	reenable_vtpr
	movzbl vapic, %eax ; fixup
	ret

up_get_tpr_ebx:
	reenable_vtpr
	movzbl vapic, %ebx ; fixup
	ret

up_get_tpr_ecx:
	reenable_vtpr
	movzbl vapic, %ecx ; fixup
	ret

up_get_tpr_edx:
	reenable_vtpr
	movzbl vapic, %edx ; fixup
	ret

up_get_tpr_esi:
	reenable_vtpr
	movzbl vapic, %esi ; fixup
	ret

up_get_tpr_edi:
	reenable_vtpr
	movzbl vapic, %edi ; fixup
	ret

up_get_tpr_ebp:
	reenable_vtpr
	movzbl vapic, %ebp ; fixup
	ret

up_get_tpr_stack:
	reenable_vtpr
	movzbl vapic, %eax ; fixup
	xchg %eax, 4(%esp)
	ret

up_set_tpr_eax:
	push %eax
	call up_set_tpr
	ret

up_set_tpr:
	pushf
	push %eax
	push %ebx
	reenable_vtpr

up_set_tpr_failed:
	mov vapic, %eax	; fixup

	mov %eax, %ebx
	mov 16(%esp), %bl

	/* %ebx = new vapic (%bl = tpr, %bh = isr, %b3 = irr) */

	lock cmpxchg %ebx, vapic ; fixup
	jnz up_set_tpr_failed

	/* compute ppr */
	cmp %bh, %bl
	jae up_tpr_is_bigger
up_isr_is_bigger:
	mov %bh, %bl
up_tpr_is_bigger:
	/* %bl = ppr */
	rol $8, %ebx
	/* now: %bl = irr, %bh = ppr */
	cmp %bh, %bl
	ja up_set_tpr_poll_irq

up_set_tpr_out:
	pop %ebx
	pop %eax
	popf
	ret $4

up_set_tpr_poll_irq:
	mov $kvm_hypercall_vapic_poll_irq, %eax
	kvm_hypercall
	jmp up_set_tpr_out

.text 1
	fixup_end = .
.text 0

/*
 * vapic format:
 *  per-vcpu records of size 2^vcpu shift.
 *     byte 0: tpr (r/w)
 *     byte 1: highest in-service interrupt (isr) (r/o); bits 3:0 are zero
 *     byte 2: zero (r/o)
 *     byte 3: highest pending interrupt (irr) (r/o)
 */
.text 2

.align 128

vapic:
. = . + vapic_size

OPTION_ROM_END