xref: /openbmc/qemu/hw/intc/ioapic.c (revision c2b38b27)
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 "qemu/error-report.h"
25 #include "monitor/monitor.h"
26 #include "hw/hw.h"
27 #include "hw/i386/pc.h"
28 #include "hw/i386/apic.h"
29 #include "hw/i386/ioapic.h"
30 #include "hw/i386/ioapic_internal.h"
31 #include "include/hw/pci/msi.h"
32 #include "sysemu/kvm.h"
33 #include "target/i386/cpu.h"
34 #include "hw/i386/apic-msidef.h"
35 #include "hw/i386/x86-iommu.h"
36 #include "trace.h"
37 
38 //#define DEBUG_IOAPIC
39 
40 #ifdef DEBUG_IOAPIC
41 #define DPRINTF(fmt, ...)                                       \
42     do { printf("ioapic: " fmt , ## __VA_ARGS__); } while (0)
43 #else
44 #define DPRINTF(fmt, ...)
45 #endif
46 
47 #define APIC_DELIVERY_MODE_SHIFT 8
48 #define APIC_POLARITY_SHIFT 14
49 #define APIC_TRIG_MODE_SHIFT 15
50 
51 static IOAPICCommonState *ioapics[MAX_IOAPICS];
52 
53 /* global variable from ioapic_common.c */
54 extern int ioapic_no;
55 
56 struct ioapic_entry_info {
57     /* fields parsed from IOAPIC entries */
58     uint8_t masked;
59     uint8_t trig_mode;
60     uint16_t dest_idx;
61     uint8_t dest_mode;
62     uint8_t delivery_mode;
63     uint8_t vector;
64 
65     /* MSI message generated from above parsed fields */
66     uint32_t addr;
67     uint32_t data;
68 };
69 
70 static void ioapic_entry_parse(uint64_t entry, struct ioapic_entry_info *info)
71 {
72     memset(info, 0, sizeof(*info));
73     info->masked = (entry >> IOAPIC_LVT_MASKED_SHIFT) & 1;
74     info->trig_mode = (entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1;
75     /*
76      * By default, this would be dest_id[8] + reserved[8]. When IR
77      * is enabled, this would be interrupt_index[15] +
78      * interrupt_format[1]. This field never means anything, but
79      * only used to generate corresponding MSI.
80      */
81     info->dest_idx = (entry >> IOAPIC_LVT_DEST_IDX_SHIFT) & 0xffff;
82     info->dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
83     info->delivery_mode = (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) \
84         & IOAPIC_DM_MASK;
85     if (info->delivery_mode == IOAPIC_DM_EXTINT) {
86         info->vector = pic_read_irq(isa_pic);
87     } else {
88         info->vector = entry & IOAPIC_VECTOR_MASK;
89     }
90 
91     info->addr = APIC_DEFAULT_ADDRESS | \
92         (info->dest_idx << MSI_ADDR_DEST_IDX_SHIFT) | \
93         (info->dest_mode << MSI_ADDR_DEST_MODE_SHIFT);
94     info->data = (info->vector << MSI_DATA_VECTOR_SHIFT) | \
95         (info->trig_mode << MSI_DATA_TRIGGER_SHIFT) | \
96         (info->delivery_mode << MSI_DATA_DELIVERY_MODE_SHIFT);
97 }
98 
99 static void ioapic_service(IOAPICCommonState *s)
100 {
101     AddressSpace *ioapic_as = PC_MACHINE(qdev_get_machine())->ioapic_as;
102     struct ioapic_entry_info info;
103     uint8_t i;
104     uint32_t mask;
105     uint64_t entry;
106 
107     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
108         mask = 1 << i;
109         if (s->irr & mask) {
110             int coalesce = 0;
111 
112             entry = s->ioredtbl[i];
113             ioapic_entry_parse(entry, &info);
114             if (!info.masked) {
115                 if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
116                     s->irr &= ~mask;
117                 } else {
118                     coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
119                     trace_ioapic_set_remote_irr(i);
120                     s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
121                 }
122 
123                 if (coalesce) {
124                     /* We are level triggered interrupts, and the
125                      * guest should be still working on previous one,
126                      * so skip it. */
127                     continue;
128                 }
129 
130 #ifdef CONFIG_KVM
131                 if (kvm_irqchip_is_split()) {
132                     if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
133                         kvm_set_irq(kvm_state, i, 1);
134                         kvm_set_irq(kvm_state, i, 0);
135                     } else {
136                         kvm_set_irq(kvm_state, i, 1);
137                     }
138                     continue;
139                 }
140 #endif
141 
142                 /* No matter whether IR is enabled, we translate
143                  * the IOAPIC message into a MSI one, and its
144                  * address space will decide whether we need a
145                  * translation. */
146                 stl_le_phys(ioapic_as, info.addr, info.data);
147             }
148         }
149     }
150 }
151 
152 static void ioapic_set_irq(void *opaque, int vector, int level)
153 {
154     IOAPICCommonState *s = opaque;
155 
156     /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
157      * to GSI 2.  GSI maps to ioapic 1-1.  This is not
158      * the cleanest way of doing it but it should work. */
159 
160     DPRINTF("%s: %s vec %x\n", __func__, level ? "raise" : "lower", vector);
161     if (vector == 0) {
162         vector = 2;
163     }
164     if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
165         uint32_t mask = 1 << vector;
166         uint64_t entry = s->ioredtbl[vector];
167 
168         if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
169             IOAPIC_TRIGGER_LEVEL) {
170             /* level triggered */
171             if (level) {
172                 s->irr |= mask;
173                 if (!(entry & IOAPIC_LVT_REMOTE_IRR)) {
174                     ioapic_service(s);
175                 }
176             } else {
177                 s->irr &= ~mask;
178             }
179         } else {
180             /* According to the 82093AA manual, we must ignore edge requests
181              * if the input pin is masked. */
182             if (level && !(entry & IOAPIC_LVT_MASKED)) {
183                 s->irr |= mask;
184                 ioapic_service(s);
185             }
186         }
187     }
188 }
189 
190 static void ioapic_update_kvm_routes(IOAPICCommonState *s)
191 {
192 #ifdef CONFIG_KVM
193     int i;
194 
195     if (kvm_irqchip_is_split()) {
196         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
197             MSIMessage msg;
198             struct ioapic_entry_info info;
199             ioapic_entry_parse(s->ioredtbl[i], &info);
200             msg.address = info.addr;
201             msg.data = info.data;
202             kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
203         }
204         kvm_irqchip_commit_routes(kvm_state);
205     }
206 #endif
207 }
208 
209 #ifdef CONFIG_KVM
210 static void ioapic_iec_notifier(void *private, bool global,
211                                 uint32_t index, uint32_t mask)
212 {
213     IOAPICCommonState *s = (IOAPICCommonState *)private;
214     /* For simplicity, we just update all the routes */
215     ioapic_update_kvm_routes(s);
216 }
217 #endif
218 
219 void ioapic_eoi_broadcast(int vector)
220 {
221     IOAPICCommonState *s;
222     uint64_t entry;
223     int i, n;
224 
225     trace_ioapic_eoi_broadcast(vector);
226 
227     for (i = 0; i < MAX_IOAPICS; i++) {
228         s = ioapics[i];
229         if (!s) {
230             continue;
231         }
232         for (n = 0; n < IOAPIC_NUM_PINS; n++) {
233             entry = s->ioredtbl[n];
234             if ((entry & IOAPIC_LVT_REMOTE_IRR)
235                 && (entry & IOAPIC_VECTOR_MASK) == vector) {
236                 trace_ioapic_clear_remote_irr(n, vector);
237                 s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
238                 if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
239                     ioapic_service(s);
240                 }
241             }
242         }
243     }
244 }
245 
246 void ioapic_dump_state(Monitor *mon, const QDict *qdict)
247 {
248     int i;
249 
250     for (i = 0; i < MAX_IOAPICS; i++) {
251         if (ioapics[i] != 0) {
252             ioapic_print_redtbl(mon, ioapics[i]);
253         }
254     }
255 }
256 
257 static uint64_t
258 ioapic_mem_read(void *opaque, hwaddr addr, unsigned int size)
259 {
260     IOAPICCommonState *s = opaque;
261     int index;
262     uint32_t val = 0;
263 
264     addr &= 0xff;
265 
266     switch (addr) {
267     case IOAPIC_IOREGSEL:
268         val = s->ioregsel;
269         break;
270     case IOAPIC_IOWIN:
271         if (size != 4) {
272             break;
273         }
274         switch (s->ioregsel) {
275         case IOAPIC_REG_ID:
276         case IOAPIC_REG_ARB:
277             val = s->id << IOAPIC_ID_SHIFT;
278             break;
279         case IOAPIC_REG_VER:
280             val = s->version |
281                 ((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
282             break;
283         default:
284             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
285             if (index >= 0 && index < IOAPIC_NUM_PINS) {
286                 if (s->ioregsel & 1) {
287                     val = s->ioredtbl[index] >> 32;
288                 } else {
289                     val = s->ioredtbl[index] & 0xffffffff;
290                 }
291             }
292         }
293         DPRINTF("read: %08x = %08x\n", s->ioregsel, val);
294         break;
295     }
296 
297     trace_ioapic_mem_read(addr, size, val);
298 
299     return val;
300 }
301 
302 /*
303  * This is to satisfy the hack in Linux kernel. One hack of it is to
304  * simulate clearing the Remote IRR bit of IOAPIC entry using the
305  * following:
306  *
307  * "For IO-APIC's with EOI register, we use that to do an explicit EOI.
308  * Otherwise, we simulate the EOI message manually by changing the trigger
309  * mode to edge and then back to level, with RTE being masked during
310  * this."
311  *
312  * (See linux kernel __eoi_ioapic_pin() comment in commit c0205701)
313  *
314  * This is based on the assumption that, Remote IRR bit will be
315  * cleared by IOAPIC hardware when configured as edge-triggered
316  * interrupts.
317  *
318  * Without this, level-triggered interrupts in IR mode might fail to
319  * work correctly.
320  */
321 static inline void
322 ioapic_fix_edge_remote_irr(uint64_t *entry)
323 {
324     if (!(*entry & IOAPIC_LVT_TRIGGER_MODE)) {
325         /* Edge-triggered interrupts, make sure remote IRR is zero */
326         *entry &= ~((uint64_t)IOAPIC_LVT_REMOTE_IRR);
327     }
328 }
329 
330 static void
331 ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
332                  unsigned int size)
333 {
334     IOAPICCommonState *s = opaque;
335     int index;
336 
337     addr &= 0xff;
338     trace_ioapic_mem_write(addr, size, val);
339 
340     switch (addr) {
341     case IOAPIC_IOREGSEL:
342         s->ioregsel = val;
343         break;
344     case IOAPIC_IOWIN:
345         if (size != 4) {
346             break;
347         }
348         DPRINTF("write: %08x = %08" PRIx64 "\n", s->ioregsel, val);
349         switch (s->ioregsel) {
350         case IOAPIC_REG_ID:
351             s->id = (val >> IOAPIC_ID_SHIFT) & IOAPIC_ID_MASK;
352             break;
353         case IOAPIC_REG_VER:
354         case IOAPIC_REG_ARB:
355             break;
356         default:
357             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
358             if (index >= 0 && index < IOAPIC_NUM_PINS) {
359                 uint64_t ro_bits = s->ioredtbl[index] & IOAPIC_RO_BITS;
360                 if (s->ioregsel & 1) {
361                     s->ioredtbl[index] &= 0xffffffff;
362                     s->ioredtbl[index] |= (uint64_t)val << 32;
363                 } else {
364                     s->ioredtbl[index] &= ~0xffffffffULL;
365                     s->ioredtbl[index] |= val;
366                 }
367                 /* restore RO bits */
368                 s->ioredtbl[index] &= IOAPIC_RW_BITS;
369                 s->ioredtbl[index] |= ro_bits;
370                 ioapic_fix_edge_remote_irr(&s->ioredtbl[index]);
371                 ioapic_service(s);
372             }
373         }
374         break;
375     case IOAPIC_EOI:
376         /* Explicit EOI is only supported for IOAPIC version 0x20 */
377         if (size != 4 || s->version != 0x20) {
378             break;
379         }
380         ioapic_eoi_broadcast(val);
381         break;
382     }
383 
384     ioapic_update_kvm_routes(s);
385 }
386 
387 static const MemoryRegionOps ioapic_io_ops = {
388     .read = ioapic_mem_read,
389     .write = ioapic_mem_write,
390     .endianness = DEVICE_NATIVE_ENDIAN,
391 };
392 
393 static void ioapic_machine_done_notify(Notifier *notifier, void *data)
394 {
395 #ifdef CONFIG_KVM
396     IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
397                                         machine_done);
398 
399     if (kvm_irqchip_is_split()) {
400         X86IOMMUState *iommu = x86_iommu_get_default();
401         if (iommu) {
402             /* Register this IOAPIC with IOMMU IEC notifier, so that
403              * when there are IR invalidates, we can be notified to
404              * update kernel IR cache. */
405             x86_iommu_iec_register_notifier(iommu, ioapic_iec_notifier, s);
406         }
407     }
408 #endif
409 }
410 
411 #define IOAPIC_VER_DEF 0x20
412 
413 static void ioapic_realize(DeviceState *dev, Error **errp)
414 {
415     IOAPICCommonState *s = IOAPIC_COMMON(dev);
416 
417     if (s->version != 0x11 && s->version != 0x20) {
418         error_report("IOAPIC only supports version 0x11 or 0x20 "
419                      "(default: 0x%x).", IOAPIC_VER_DEF);
420         exit(1);
421     }
422 
423     memory_region_init_io(&s->io_memory, OBJECT(s), &ioapic_io_ops, s,
424                           "ioapic", 0x1000);
425 
426     qdev_init_gpio_in(dev, ioapic_set_irq, IOAPIC_NUM_PINS);
427 
428     ioapics[ioapic_no] = s;
429     s->machine_done.notify = ioapic_machine_done_notify;
430     qemu_add_machine_init_done_notifier(&s->machine_done);
431 }
432 
433 static Property ioapic_properties[] = {
434     DEFINE_PROP_UINT8("version", IOAPICCommonState, version, IOAPIC_VER_DEF),
435     DEFINE_PROP_END_OF_LIST(),
436 };
437 
438 static void ioapic_class_init(ObjectClass *klass, void *data)
439 {
440     IOAPICCommonClass *k = IOAPIC_COMMON_CLASS(klass);
441     DeviceClass *dc = DEVICE_CLASS(klass);
442 
443     k->realize = ioapic_realize;
444     /*
445      * If APIC is in kernel, we need to update the kernel cache after
446      * migration, otherwise first 24 gsi routes will be invalid.
447      */
448     k->post_load = ioapic_update_kvm_routes;
449     dc->reset = ioapic_reset_common;
450     dc->props = ioapic_properties;
451 }
452 
453 static const TypeInfo ioapic_info = {
454     .name          = "ioapic",
455     .parent        = TYPE_IOAPIC_COMMON,
456     .instance_size = sizeof(IOAPICCommonState),
457     .class_init    = ioapic_class_init,
458 };
459 
460 static void ioapic_register_types(void)
461 {
462     type_register_static(&ioapic_info);
463 }
464 
465 type_init(ioapic_register_types)
466