xref: /qemu/hw/intc/ioapic.c (revision c52125ab)
1 /*
2  *  ioapic.c IOAPIC emulation logic
3  *
4  *  Copyright (c) 2004-2005 Fabrice Bellard
5  *
6  *  Split the ioapic logic from apic.c
7  *  Xiantao Zhang <xiantao.zhang@intel.com>
8  *
9  * This library is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2 of the License, or (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include "qemu/osdep.h"
24 #include "monitor/monitor.h"
25 #include "hw/hw.h"
26 #include "hw/i386/pc.h"
27 #include "hw/i386/apic.h"
28 #include "hw/i386/ioapic.h"
29 #include "hw/i386/ioapic_internal.h"
30 #include "include/hw/pci/msi.h"
31 #include "sysemu/kvm.h"
32 
33 //#define DEBUG_IOAPIC
34 
35 #ifdef DEBUG_IOAPIC
36 #define DPRINTF(fmt, ...)                                       \
37     do { printf("ioapic: " fmt , ## __VA_ARGS__); } while (0)
38 #else
39 #define DPRINTF(fmt, ...)
40 #endif
41 
42 #define APIC_DELIVERY_MODE_SHIFT 8
43 #define APIC_POLARITY_SHIFT 14
44 #define APIC_TRIG_MODE_SHIFT 15
45 
46 static IOAPICCommonState *ioapics[MAX_IOAPICS];
47 
48 /* global variable from ioapic_common.c */
49 extern int ioapic_no;
50 
51 static void ioapic_service(IOAPICCommonState *s)
52 {
53     uint8_t i;
54     uint8_t trig_mode;
55     uint8_t vector;
56     uint8_t delivery_mode;
57     uint32_t mask;
58     uint64_t entry;
59     uint8_t dest;
60     uint8_t dest_mode;
61 
62     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
63         mask = 1 << i;
64         if (s->irr & mask) {
65             int coalesce = 0;
66 
67             entry = s->ioredtbl[i];
68             if (!(entry & IOAPIC_LVT_MASKED)) {
69                 trig_mode = ((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1);
70                 dest = entry >> IOAPIC_LVT_DEST_SHIFT;
71                 dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
72                 delivery_mode =
73                     (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) & IOAPIC_DM_MASK;
74                 if (trig_mode == IOAPIC_TRIGGER_EDGE) {
75                     s->irr &= ~mask;
76                 } else {
77                     coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
78                     s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
79                 }
80                 if (delivery_mode == IOAPIC_DM_EXTINT) {
81                     vector = pic_read_irq(isa_pic);
82                 } else {
83                     vector = entry & IOAPIC_VECTOR_MASK;
84                 }
85 #ifdef CONFIG_KVM
86                 if (kvm_irqchip_is_split()) {
87                     if (trig_mode == IOAPIC_TRIGGER_EDGE) {
88                         kvm_set_irq(kvm_state, i, 1);
89                         kvm_set_irq(kvm_state, i, 0);
90                     } else {
91                         if (!coalesce) {
92                             kvm_set_irq(kvm_state, i, 1);
93                         }
94                     }
95                     continue;
96                 }
97 #else
98                 (void)coalesce;
99 #endif
100                 apic_deliver_irq(dest, dest_mode, delivery_mode, vector,
101                                  trig_mode);
102             }
103         }
104     }
105 }
106 
107 static void ioapic_set_irq(void *opaque, int vector, int level)
108 {
109     IOAPICCommonState *s = opaque;
110 
111     /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
112      * to GSI 2.  GSI maps to ioapic 1-1.  This is not
113      * the cleanest way of doing it but it should work. */
114 
115     DPRINTF("%s: %s vec %x\n", __func__, level ? "raise" : "lower", vector);
116     if (vector == 0) {
117         vector = 2;
118     }
119     if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
120         uint32_t mask = 1 << vector;
121         uint64_t entry = s->ioredtbl[vector];
122 
123         if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
124             IOAPIC_TRIGGER_LEVEL) {
125             /* level triggered */
126             if (level) {
127                 s->irr |= mask;
128                 if (!(entry & IOAPIC_LVT_REMOTE_IRR)) {
129                     ioapic_service(s);
130                 }
131             } else {
132                 s->irr &= ~mask;
133             }
134         } else {
135             /* According to the 82093AA manual, we must ignore edge requests
136              * if the input pin is masked. */
137             if (level && !(entry & IOAPIC_LVT_MASKED)) {
138                 s->irr |= mask;
139                 ioapic_service(s);
140             }
141         }
142     }
143 }
144 
145 static void ioapic_update_kvm_routes(IOAPICCommonState *s)
146 {
147 #ifdef CONFIG_KVM
148     int i;
149 
150     if (kvm_irqchip_is_split()) {
151         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
152             uint64_t entry = s->ioredtbl[i];
153             uint8_t trig_mode;
154             uint8_t delivery_mode;
155             uint8_t dest;
156             uint8_t dest_mode;
157             uint64_t pin_polarity;
158             MSIMessage msg;
159 
160             trig_mode = ((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1);
161             dest = entry >> IOAPIC_LVT_DEST_SHIFT;
162             dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
163             pin_polarity = (entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1;
164             delivery_mode =
165                 (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) & IOAPIC_DM_MASK;
166 
167             msg.address = APIC_DEFAULT_ADDRESS;
168             msg.address |= dest_mode << 2;
169             msg.address |= dest << 12;
170 
171             msg.data = entry & IOAPIC_VECTOR_MASK;
172             msg.data |= delivery_mode << APIC_DELIVERY_MODE_SHIFT;
173             msg.data |= pin_polarity << APIC_POLARITY_SHIFT;
174             msg.data |= trig_mode << APIC_TRIG_MODE_SHIFT;
175 
176             kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
177         }
178         kvm_irqchip_commit_routes(kvm_state);
179     }
180 #endif
181 }
182 
183 void ioapic_eoi_broadcast(int vector)
184 {
185     IOAPICCommonState *s;
186     uint64_t entry;
187     int i, n;
188 
189     for (i = 0; i < MAX_IOAPICS; i++) {
190         s = ioapics[i];
191         if (!s) {
192             continue;
193         }
194         for (n = 0; n < IOAPIC_NUM_PINS; n++) {
195             entry = s->ioredtbl[n];
196             if ((entry & IOAPIC_LVT_REMOTE_IRR)
197                 && (entry & IOAPIC_VECTOR_MASK) == vector) {
198                 s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
199                 if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
200                     ioapic_service(s);
201                 }
202             }
203         }
204     }
205 }
206 
207 void ioapic_dump_state(Monitor *mon, const QDict *qdict)
208 {
209     int i;
210 
211     for (i = 0; i < MAX_IOAPICS; i++) {
212         if (ioapics[i] != 0) {
213             ioapic_print_redtbl(mon, ioapics[i]);
214         }
215     }
216 }
217 
218 static uint64_t
219 ioapic_mem_read(void *opaque, hwaddr addr, unsigned int size)
220 {
221     IOAPICCommonState *s = opaque;
222     int index;
223     uint32_t val = 0;
224 
225     switch (addr & 0xff) {
226     case IOAPIC_IOREGSEL:
227         val = s->ioregsel;
228         break;
229     case IOAPIC_IOWIN:
230         if (size != 4) {
231             break;
232         }
233         switch (s->ioregsel) {
234         case IOAPIC_REG_ID:
235         case IOAPIC_REG_ARB:
236             val = s->id << IOAPIC_ID_SHIFT;
237             break;
238         case IOAPIC_REG_VER:
239             val = IOAPIC_VERSION |
240                 ((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
241             break;
242         default:
243             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
244             if (index >= 0 && index < IOAPIC_NUM_PINS) {
245                 if (s->ioregsel & 1) {
246                     val = s->ioredtbl[index] >> 32;
247                 } else {
248                     val = s->ioredtbl[index] & 0xffffffff;
249                 }
250             }
251         }
252         DPRINTF("read: %08x = %08x\n", s->ioregsel, val);
253         break;
254     }
255     return val;
256 }
257 
258 /*
259  * This is to satisfy the hack in Linux kernel. One hack of it is to
260  * simulate clearing the Remote IRR bit of IOAPIC entry using the
261  * following:
262  *
263  * "For IO-APIC's with EOI register, we use that to do an explicit EOI.
264  * Otherwise, we simulate the EOI message manually by changing the trigger
265  * mode to edge and then back to level, with RTE being masked during
266  * this."
267  *
268  * (See linux kernel __eoi_ioapic_pin() comment in commit c0205701)
269  *
270  * This is based on the assumption that, Remote IRR bit will be
271  * cleared by IOAPIC hardware when configured as edge-triggered
272  * interrupts.
273  *
274  * Without this, level-triggered interrupts in IR mode might fail to
275  * work correctly.
276  */
277 static inline void
278 ioapic_fix_edge_remote_irr(uint64_t *entry)
279 {
280     if (!(*entry & IOAPIC_LVT_TRIGGER_MODE)) {
281         /* Edge-triggered interrupts, make sure remote IRR is zero */
282         *entry &= ~((uint64_t)IOAPIC_LVT_REMOTE_IRR);
283     }
284 }
285 
286 static void
287 ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
288                  unsigned int size)
289 {
290     IOAPICCommonState *s = opaque;
291     int index;
292 
293     switch (addr & 0xff) {
294     case IOAPIC_IOREGSEL:
295         s->ioregsel = val;
296         break;
297     case IOAPIC_IOWIN:
298         if (size != 4) {
299             break;
300         }
301         DPRINTF("write: %08x = %08" PRIx64 "\n", s->ioregsel, val);
302         switch (s->ioregsel) {
303         case IOAPIC_REG_ID:
304             s->id = (val >> IOAPIC_ID_SHIFT) & IOAPIC_ID_MASK;
305             break;
306         case IOAPIC_REG_VER:
307         case IOAPIC_REG_ARB:
308             break;
309         default:
310             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
311             if (index >= 0 && index < IOAPIC_NUM_PINS) {
312                 uint64_t ro_bits = s->ioredtbl[index] & IOAPIC_RO_BITS;
313                 if (s->ioregsel & 1) {
314                     s->ioredtbl[index] &= 0xffffffff;
315                     s->ioredtbl[index] |= (uint64_t)val << 32;
316                 } else {
317                     s->ioredtbl[index] &= ~0xffffffffULL;
318                     s->ioredtbl[index] |= val;
319                 }
320                 /* restore RO bits */
321                 s->ioredtbl[index] &= IOAPIC_RW_BITS;
322                 s->ioredtbl[index] |= ro_bits;
323                 ioapic_fix_edge_remote_irr(&s->ioredtbl[index]);
324                 ioapic_service(s);
325             }
326         }
327         break;
328     }
329 
330     ioapic_update_kvm_routes(s);
331 }
332 
333 static const MemoryRegionOps ioapic_io_ops = {
334     .read = ioapic_mem_read,
335     .write = ioapic_mem_write,
336     .endianness = DEVICE_NATIVE_ENDIAN,
337 };
338 
339 static void ioapic_realize(DeviceState *dev, Error **errp)
340 {
341     IOAPICCommonState *s = IOAPIC_COMMON(dev);
342 
343     memory_region_init_io(&s->io_memory, OBJECT(s), &ioapic_io_ops, s,
344                           "ioapic", 0x1000);
345 
346     qdev_init_gpio_in(dev, ioapic_set_irq, IOAPIC_NUM_PINS);
347 
348     ioapics[ioapic_no] = s;
349 }
350 
351 static void ioapic_class_init(ObjectClass *klass, void *data)
352 {
353     IOAPICCommonClass *k = IOAPIC_COMMON_CLASS(klass);
354     DeviceClass *dc = DEVICE_CLASS(klass);
355 
356     k->realize = ioapic_realize;
357     dc->reset = ioapic_reset_common;
358 }
359 
360 static const TypeInfo ioapic_info = {
361     .name          = "ioapic",
362     .parent        = TYPE_IOAPIC_COMMON,
363     .instance_size = sizeof(IOAPICCommonState),
364     .class_init    = ioapic_class_init,
365 };
366 
367 static void ioapic_register_types(void)
368 {
369     type_register_static(&ioapic_info);
370 }
371 
372 type_init(ioapic_register_types)
373