xref: /openbmc/qemu/hw/intc/spapr_xive_kvm.c (revision 07f27705)
1 /*
2  * QEMU PowerPC sPAPR XIVE interrupt controller model
3  *
4  * Copyright (c) 2017-2019, IBM Corporation.
5  *
6  * This code is licensed under the GPL version 2 or later. See the
7  * COPYING file in the top-level directory.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "qemu/log.h"
12 #include "qemu/error-report.h"
13 #include "qapi/error.h"
14 #include "target/ppc/cpu.h"
15 #include "sysemu/cpus.h"
16 #include "sysemu/kvm.h"
17 #include "sysemu/runstate.h"
18 #include "hw/ppc/spapr.h"
19 #include "hw/ppc/spapr_cpu_core.h"
20 #include "hw/ppc/spapr_xive.h"
21 #include "hw/ppc/xive.h"
22 #include "kvm_ppc.h"
23 #include "trace.h"
24 
25 #include <sys/ioctl.h>
26 
27 /*
28  * Helpers for CPU hotplug
29  *
30  * TODO: make a common KVMEnabledCPU layer for XICS and XIVE
31  */
32 typedef struct KVMEnabledCPU {
33     unsigned long vcpu_id;
34     QLIST_ENTRY(KVMEnabledCPU) node;
35 } KVMEnabledCPU;
36 
37 static QLIST_HEAD(, KVMEnabledCPU)
38     kvm_enabled_cpus = QLIST_HEAD_INITIALIZER(&kvm_enabled_cpus);
39 
kvm_cpu_is_enabled(CPUState * cs)40 static bool kvm_cpu_is_enabled(CPUState *cs)
41 {
42     KVMEnabledCPU *enabled_cpu;
43     unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
44 
45     QLIST_FOREACH(enabled_cpu, &kvm_enabled_cpus, node) {
46         if (enabled_cpu->vcpu_id == vcpu_id) {
47             return true;
48         }
49     }
50     return false;
51 }
52 
kvm_cpu_enable(CPUState * cs)53 static void kvm_cpu_enable(CPUState *cs)
54 {
55     KVMEnabledCPU *enabled_cpu;
56     unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
57 
58     enabled_cpu = g_malloc(sizeof(*enabled_cpu));
59     enabled_cpu->vcpu_id = vcpu_id;
60     QLIST_INSERT_HEAD(&kvm_enabled_cpus, enabled_cpu, node);
61 }
62 
kvm_cpu_disable_all(void)63 static void kvm_cpu_disable_all(void)
64 {
65     KVMEnabledCPU *enabled_cpu, *next;
66 
67     QLIST_FOREACH_SAFE(enabled_cpu, &kvm_enabled_cpus, node, next) {
68         QLIST_REMOVE(enabled_cpu, node);
69         g_free(enabled_cpu);
70     }
71 }
72 
73 /*
74  * XIVE Thread Interrupt Management context (KVM)
75  */
76 
kvmppc_xive_cpu_set_state(XiveTCTX * tctx,Error ** errp)77 int kvmppc_xive_cpu_set_state(XiveTCTX *tctx, Error **errp)
78 {
79     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
80     uint64_t state[2];
81     int ret;
82 
83     assert(xive->fd != -1);
84 
85     /* word0 and word1 of the OS ring. */
86     state[0] = *((uint64_t *) &tctx->regs[TM_QW1_OS]);
87 
88     ret = kvm_set_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
89     if (ret != 0) {
90         error_setg_errno(errp, -ret,
91                          "XIVE: could not restore KVM state of CPU %ld",
92                          kvm_arch_vcpu_id(tctx->cs));
93         return ret;
94     }
95 
96     return 0;
97 }
98 
kvmppc_xive_cpu_get_state(XiveTCTX * tctx,Error ** errp)99 int kvmppc_xive_cpu_get_state(XiveTCTX *tctx, Error **errp)
100 {
101     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
102     uint64_t state[2] = { 0 };
103     int ret;
104 
105     assert(xive->fd != -1);
106 
107     ret = kvm_get_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
108     if (ret != 0) {
109         error_setg_errno(errp, -ret,
110                          "XIVE: could not capture KVM state of CPU %ld",
111                          kvm_arch_vcpu_id(tctx->cs));
112         return ret;
113     }
114 
115     /* word0 and word1 of the OS ring. */
116     *((uint64_t *) &tctx->regs[TM_QW1_OS]) = state[0];
117 
118     return 0;
119 }
120 
121 typedef struct {
122     XiveTCTX *tctx;
123     Error **errp;
124     int ret;
125 } XiveCpuGetState;
126 
kvmppc_xive_cpu_do_synchronize_state(CPUState * cpu,run_on_cpu_data arg)127 static void kvmppc_xive_cpu_do_synchronize_state(CPUState *cpu,
128                                                  run_on_cpu_data arg)
129 {
130     XiveCpuGetState *s = arg.host_ptr;
131 
132     s->ret = kvmppc_xive_cpu_get_state(s->tctx, s->errp);
133 }
134 
kvmppc_xive_cpu_synchronize_state(XiveTCTX * tctx,Error ** errp)135 int kvmppc_xive_cpu_synchronize_state(XiveTCTX *tctx, Error **errp)
136 {
137     XiveCpuGetState s = {
138         .tctx = tctx,
139         .errp = errp,
140     };
141 
142     /*
143      * Kick the vCPU to make sure they are available for the KVM ioctl.
144      */
145     run_on_cpu(tctx->cs, kvmppc_xive_cpu_do_synchronize_state,
146                RUN_ON_CPU_HOST_PTR(&s));
147 
148     return s.ret;
149 }
150 
kvmppc_xive_cpu_connect(XiveTCTX * tctx,Error ** errp)151 int kvmppc_xive_cpu_connect(XiveTCTX *tctx, Error **errp)
152 {
153     ERRP_GUARD();
154     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
155     unsigned long vcpu_id;
156     int ret;
157 
158     assert(xive->fd != -1);
159 
160     /* Check if CPU was hot unplugged and replugged. */
161     if (kvm_cpu_is_enabled(tctx->cs)) {
162         return 0;
163     }
164 
165     vcpu_id = kvm_arch_vcpu_id(tctx->cs);
166 
167     trace_kvm_xive_cpu_connect(vcpu_id);
168 
169     ret = kvm_vcpu_enable_cap(tctx->cs, KVM_CAP_PPC_IRQ_XIVE, 0, xive->fd,
170                               vcpu_id, 0);
171     if (ret < 0) {
172         error_setg_errno(errp, -ret,
173                          "XIVE: unable to connect CPU%ld to KVM device",
174                          vcpu_id);
175         if (ret == -ENOSPC) {
176             error_append_hint(errp, "Try -smp maxcpus=N with N < %u\n",
177                               MACHINE(qdev_get_machine())->smp.max_cpus);
178         }
179         return ret;
180     }
181 
182     kvm_cpu_enable(tctx->cs);
183     return 0;
184 }
185 
186 /*
187  * XIVE Interrupt Source (KVM)
188  */
189 
kvmppc_xive_set_source_config(SpaprXive * xive,uint32_t lisn,XiveEAS * eas,Error ** errp)190 int kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
191                                   Error **errp)
192 {
193     uint32_t end_idx;
194     uint32_t end_blk;
195     uint8_t priority;
196     uint32_t server;
197     bool masked;
198     uint32_t eisn;
199     uint64_t kvm_src;
200 
201     assert(xive_eas_is_valid(eas));
202 
203     end_idx = xive_get_field64(EAS_END_INDEX, eas->w);
204     end_blk = xive_get_field64(EAS_END_BLOCK, eas->w);
205     eisn = xive_get_field64(EAS_END_DATA, eas->w);
206     masked = xive_eas_is_masked(eas);
207 
208     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
209 
210     kvm_src = priority << KVM_XIVE_SOURCE_PRIORITY_SHIFT &
211         KVM_XIVE_SOURCE_PRIORITY_MASK;
212     kvm_src |= server << KVM_XIVE_SOURCE_SERVER_SHIFT &
213         KVM_XIVE_SOURCE_SERVER_MASK;
214     kvm_src |= ((uint64_t) masked << KVM_XIVE_SOURCE_MASKED_SHIFT) &
215         KVM_XIVE_SOURCE_MASKED_MASK;
216     kvm_src |= ((uint64_t)eisn << KVM_XIVE_SOURCE_EISN_SHIFT) &
217         KVM_XIVE_SOURCE_EISN_MASK;
218 
219     return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_CONFIG, lisn,
220                              &kvm_src, true, errp);
221 }
222 
kvmppc_xive_sync_source(SpaprXive * xive,uint32_t lisn,Error ** errp)223 void kvmppc_xive_sync_source(SpaprXive *xive, uint32_t lisn, Error **errp)
224 {
225     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_SYNC, lisn,
226                       NULL, true, errp);
227 }
228 
229 /*
230  * At reset, the interrupt sources are simply created and MASKED. We
231  * only need to inform the KVM XIVE device about their type: LSI or
232  * MSI.
233  */
kvmppc_xive_source_reset_one(XiveSource * xsrc,int srcno,Error ** errp)234 int kvmppc_xive_source_reset_one(XiveSource *xsrc, int srcno, Error **errp)
235 {
236     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
237     uint64_t state = 0;
238 
239     trace_kvm_xive_source_reset(srcno);
240 
241     assert(xive->fd != -1);
242 
243     if (xive_source_irq_is_lsi(xsrc, srcno)) {
244         state |= KVM_XIVE_LEVEL_SENSITIVE;
245         if (xive_source_is_asserted(xsrc, srcno)) {
246             state |= KVM_XIVE_LEVEL_ASSERTED;
247         }
248     }
249 
250     return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE, srcno, &state,
251                              true, errp);
252 }
253 
kvmppc_xive_source_reset(XiveSource * xsrc,Error ** errp)254 static int kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
255 {
256     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
257     int i;
258 
259     for (i = 0; i < xsrc->nr_irqs; i++) {
260         int ret;
261 
262         if (!xive_eas_is_valid(&xive->eat[i])) {
263             continue;
264         }
265 
266         ret = kvmppc_xive_source_reset_one(xsrc, i, errp);
267         if (ret < 0) {
268             return ret;
269         }
270     }
271 
272     return 0;
273 }
274 
275 /*
276  * This is used to perform the magic loads on the ESB pages, described
277  * in xive.h.
278  *
279  * Memory barriers should not be needed for loads (no store for now).
280  */
xive_esb_rw(XiveSource * xsrc,int srcno,uint32_t offset,uint64_t data,bool write)281 static uint64_t xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
282                             uint64_t data, bool write)
283 {
284     uint64_t *addr = xsrc->esb_mmap + xive_source_esb_mgmt(xsrc, srcno) +
285         offset;
286 
287     if (write) {
288         *addr = cpu_to_be64(data);
289         return -1;
290     } else {
291         /* Prevent the compiler from optimizing away the load */
292         volatile uint64_t value = be64_to_cpu(*addr);
293         return value;
294     }
295 }
296 
xive_esb_read(XiveSource * xsrc,int srcno,uint32_t offset)297 static uint8_t xive_esb_read(XiveSource *xsrc, int srcno, uint32_t offset)
298 {
299     return xive_esb_rw(xsrc, srcno, offset, 0, 0) & 0x3;
300 }
301 
kvmppc_xive_esb_trigger(XiveSource * xsrc,int srcno)302 static void kvmppc_xive_esb_trigger(XiveSource *xsrc, int srcno)
303 {
304     xive_esb_rw(xsrc, srcno, 0, 0, true);
305 }
306 
kvmppc_xive_esb_rw(XiveSource * xsrc,int srcno,uint32_t offset,uint64_t data,bool write)307 uint64_t kvmppc_xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
308                             uint64_t data, bool write)
309 {
310     if (write) {
311         return xive_esb_rw(xsrc, srcno, offset, data, 1);
312     }
313 
314     /*
315      * Special Load EOI handling for LSI sources. Q bit is never set
316      * and the interrupt should be re-triggered if the level is still
317      * asserted.
318      */
319     if (xive_source_irq_is_lsi(xsrc, srcno) &&
320         offset == XIVE_ESB_LOAD_EOI) {
321         xive_esb_read(xsrc, srcno, XIVE_ESB_SET_PQ_00);
322         if (xive_source_is_asserted(xsrc, srcno)) {
323             kvmppc_xive_esb_trigger(xsrc, srcno);
324         }
325         return 0;
326     } else {
327         return xive_esb_rw(xsrc, srcno, offset, 0, 0);
328     }
329 }
330 
kvmppc_xive_source_get_state(XiveSource * xsrc)331 static void kvmppc_xive_source_get_state(XiveSource *xsrc)
332 {
333     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
334     int i;
335 
336     for (i = 0; i < xsrc->nr_irqs; i++) {
337         uint8_t pq;
338 
339         if (!xive_eas_is_valid(&xive->eat[i])) {
340             continue;
341         }
342 
343         /* Perform a load without side effect to retrieve the PQ bits */
344         pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
345 
346         /* and save PQ locally */
347         xive_source_esb_set(xsrc, i, pq);
348     }
349 }
350 
kvmppc_xive_source_set_irq(void * opaque,int srcno,int val)351 void kvmppc_xive_source_set_irq(void *opaque, int srcno, int val)
352 {
353     XiveSource *xsrc = opaque;
354 
355     if (!xive_source_irq_is_lsi(xsrc, srcno)) {
356         if (!val) {
357             return;
358         }
359     } else {
360         xive_source_set_asserted(xsrc, srcno, val);
361     }
362 
363     kvmppc_xive_esb_trigger(xsrc, srcno);
364 }
365 
366 /*
367  * sPAPR XIVE interrupt controller (KVM)
368  */
kvmppc_xive_get_queue_config(SpaprXive * xive,uint8_t end_blk,uint32_t end_idx,XiveEND * end,Error ** errp)369 int kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
370                                  uint32_t end_idx, XiveEND *end,
371                                  Error **errp)
372 {
373     struct kvm_ppc_xive_eq kvm_eq = { 0 };
374     uint64_t kvm_eq_idx;
375     uint8_t priority;
376     uint32_t server;
377     int ret;
378 
379     assert(xive_end_is_valid(end));
380 
381     /* Encode the tuple (server, prio) as a KVM EQ index */
382     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
383 
384     kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
385             KVM_XIVE_EQ_PRIORITY_MASK;
386     kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
387         KVM_XIVE_EQ_SERVER_MASK;
388 
389     ret = kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
390                             &kvm_eq, false, errp);
391     if (ret < 0) {
392         return ret;
393     }
394 
395     /*
396      * The EQ index and toggle bit are updated by HW. These are the
397      * only fields from KVM we want to update QEMU with. The other END
398      * fields should already be in the QEMU END table.
399      */
400     end->w1 = xive_set_field32(END_W1_GENERATION, 0ul, kvm_eq.qtoggle) |
401         xive_set_field32(END_W1_PAGE_OFF, 0ul, kvm_eq.qindex);
402 
403     return 0;
404 }
405 
kvmppc_xive_set_queue_config(SpaprXive * xive,uint8_t end_blk,uint32_t end_idx,XiveEND * end,Error ** errp)406 int kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
407                                  uint32_t end_idx, XiveEND *end,
408                                  Error **errp)
409 {
410     struct kvm_ppc_xive_eq kvm_eq = { 0 };
411     uint64_t kvm_eq_idx;
412     uint8_t priority;
413     uint32_t server;
414 
415     /*
416      * Build the KVM state from the local END structure.
417      */
418 
419     kvm_eq.flags = 0;
420     if (xive_get_field32(END_W0_UCOND_NOTIFY, end->w0)) {
421         kvm_eq.flags |= KVM_XIVE_EQ_ALWAYS_NOTIFY;
422     }
423 
424     /*
425      * If the hcall is disabling the EQ, set the size and page address
426      * to zero. When migrating, only valid ENDs are taken into
427      * account.
428      */
429     if (xive_end_is_valid(end)) {
430         kvm_eq.qshift = xive_get_field32(END_W0_QSIZE, end->w0) + 12;
431         kvm_eq.qaddr  = xive_end_qaddr(end);
432         /*
433          * The EQ toggle bit and index should only be relevant when
434          * restoring the EQ state
435          */
436         kvm_eq.qtoggle = xive_get_field32(END_W1_GENERATION, end->w1);
437         kvm_eq.qindex  = xive_get_field32(END_W1_PAGE_OFF, end->w1);
438     } else {
439         kvm_eq.qshift = 0;
440         kvm_eq.qaddr  = 0;
441     }
442 
443     /* Encode the tuple (server, prio) as a KVM EQ index */
444     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
445 
446     kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
447             KVM_XIVE_EQ_PRIORITY_MASK;
448     kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
449         KVM_XIVE_EQ_SERVER_MASK;
450 
451     return
452         kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
453                           &kvm_eq, true, errp);
454 }
455 
kvmppc_xive_reset(SpaprXive * xive,Error ** errp)456 void kvmppc_xive_reset(SpaprXive *xive, Error **errp)
457 {
458     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL, KVM_DEV_XIVE_RESET,
459                       NULL, true, errp);
460 }
461 
kvmppc_xive_get_queues(SpaprXive * xive,Error ** errp)462 static int kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
463 {
464     int i;
465     int ret;
466 
467     for (i = 0; i < xive->nr_ends; i++) {
468         if (!xive_end_is_valid(&xive->endt[i])) {
469             continue;
470         }
471 
472         ret = kvmppc_xive_get_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
473                                            &xive->endt[i], errp);
474         if (ret < 0) {
475             return ret;
476         }
477     }
478 
479     return 0;
480 }
481 
482 /*
483  * The primary goal of the XIVE VM change handler is to mark the EQ
484  * pages dirty when all XIVE event notifications have stopped.
485  *
486  * Whenever the VM is stopped, the VM change handler sets the source
487  * PQs to PENDING to stop the flow of events and to possibly catch a
488  * triggered interrupt occurring while the VM is stopped. The previous
489  * state is saved in anticipation of a migration. The XIVE controller
490  * is then synced through KVM to flush any in-flight event
491  * notification and stabilize the EQs.
492  *
493  * At this stage, we can mark the EQ page dirty and let a migration
494  * sequence transfer the EQ pages to the destination, which is done
495  * just after the stop state.
496  *
497  * The previous configuration of the sources is restored when the VM
498  * runs again. If an interrupt was queued while the VM was stopped,
499  * simply generate a trigger.
500  */
kvmppc_xive_change_state_handler(void * opaque,bool running,RunState state)501 static void kvmppc_xive_change_state_handler(void *opaque, bool running,
502                                              RunState state)
503 {
504     SpaprXive *xive = opaque;
505     XiveSource *xsrc = &xive->source;
506     Error *local_err = NULL;
507     int i;
508 
509     /*
510      * Restore the sources to their initial state. This is called when
511      * the VM resumes after a stop or a migration.
512      */
513     if (running) {
514         for (i = 0; i < xsrc->nr_irqs; i++) {
515             uint8_t pq;
516             uint8_t old_pq;
517 
518             if (!xive_eas_is_valid(&xive->eat[i])) {
519                 continue;
520             }
521 
522             pq = xive_source_esb_get(xsrc, i);
523             old_pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_00 + (pq << 8));
524 
525             /*
526              * An interrupt was queued while the VM was stopped,
527              * generate a trigger.
528              */
529             if (pq == XIVE_ESB_RESET && old_pq == XIVE_ESB_QUEUED) {
530                 kvmppc_xive_esb_trigger(xsrc, i);
531             }
532         }
533 
534         return;
535     }
536 
537     /*
538      * Mask the sources, to stop the flow of event notifications, and
539      * save the PQs locally in the XiveSource object. The XiveSource
540      * state will be collected later on by its vmstate handler if a
541      * migration is in progress.
542      */
543     for (i = 0; i < xsrc->nr_irqs; i++) {
544         uint8_t pq;
545 
546         if (!xive_eas_is_valid(&xive->eat[i])) {
547             continue;
548         }
549 
550         pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
551 
552         /*
553          * PQ is set to PENDING to possibly catch a triggered
554          * interrupt occurring while the VM is stopped (hotplug event
555          * for instance) .
556          */
557         if (pq != XIVE_ESB_OFF) {
558             pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_10);
559         }
560         xive_source_esb_set(xsrc, i, pq);
561     }
562 
563     /*
564      * Sync the XIVE controller in KVM, to flush in-flight event
565      * notification that should be enqueued in the EQs and mark the
566      * XIVE EQ pages dirty to collect all updates.
567      */
568     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
569                       KVM_DEV_XIVE_EQ_SYNC, NULL, true, &local_err);
570     if (local_err) {
571         error_report_err(local_err);
572         return;
573     }
574 }
575 
kvmppc_xive_synchronize_state(SpaprXive * xive,Error ** errp)576 void kvmppc_xive_synchronize_state(SpaprXive *xive, Error **errp)
577 {
578     assert(xive->fd != -1);
579 
580     /*
581      * When the VM is stopped, the sources are masked and the previous
582      * state is saved in anticipation of a migration. We should not
583      * synchronize the source state in that case else we will override
584      * the saved state.
585      */
586     if (runstate_is_running()) {
587         kvmppc_xive_source_get_state(&xive->source);
588     }
589 
590     /* EAT: there is no extra state to query from KVM */
591 
592     /* ENDT */
593     kvmppc_xive_get_queues(xive, errp);
594 }
595 
596 /*
597  * The SpaprXive 'pre_save' method is called by the vmstate handler of
598  * the SpaprXive model, after the XIVE controller is synced in the VM
599  * change handler.
600  */
kvmppc_xive_pre_save(SpaprXive * xive)601 int kvmppc_xive_pre_save(SpaprXive *xive)
602 {
603     Error *local_err = NULL;
604     int ret;
605 
606     assert(xive->fd != -1);
607 
608     /* EAT: there is no extra state to query from KVM */
609 
610     /* ENDT */
611     ret = kvmppc_xive_get_queues(xive, &local_err);
612     if (ret < 0) {
613         error_report_err(local_err);
614         return ret;
615     }
616 
617     return 0;
618 }
619 
620 /*
621  * The SpaprXive 'post_load' method is not called by a vmstate
622  * handler. It is called at the sPAPR machine level at the end of the
623  * migration sequence by the sPAPR IRQ backend 'post_load' method,
624  * when all XIVE states have been transferred and loaded.
625  */
kvmppc_xive_post_load(SpaprXive * xive,int version_id)626 int kvmppc_xive_post_load(SpaprXive *xive, int version_id)
627 {
628     Error *local_err = NULL;
629     CPUState *cs;
630     int i;
631     int ret;
632 
633     /* The KVM XIVE device should be in use */
634     assert(xive->fd != -1);
635 
636     /* Restore the ENDT first. The targeting depends on it. */
637     for (i = 0; i < xive->nr_ends; i++) {
638         if (!xive_end_is_valid(&xive->endt[i])) {
639             continue;
640         }
641 
642         ret = kvmppc_xive_set_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
643                                            &xive->endt[i], &local_err);
644         if (ret < 0) {
645             goto fail;
646         }
647     }
648 
649     /* Restore the EAT */
650     for (i = 0; i < xive->nr_irqs; i++) {
651         if (!xive_eas_is_valid(&xive->eat[i])) {
652             continue;
653         }
654 
655         /*
656          * We can only restore the source config if the source has been
657          * previously set in KVM. Since we don't do that for all interrupts
658          * at reset time anymore, let's do it now.
659          */
660         ret = kvmppc_xive_source_reset_one(&xive->source, i, &local_err);
661         if (ret < 0) {
662             goto fail;
663         }
664 
665         ret = kvmppc_xive_set_source_config(xive, i, &xive->eat[i], &local_err);
666         if (ret < 0) {
667             goto fail;
668         }
669     }
670 
671     /*
672      * Restore the thread interrupt contexts of initial CPUs.
673      *
674      * The context of hotplugged CPUs is restored later, by the
675      * 'post_load' handler of the XiveTCTX model because they are not
676      * available at the time the SpaprXive 'post_load' method is
677      * called. We can not restore the context of all CPUs in the
678      * 'post_load' handler of XiveTCTX because the machine is not
679      * necessarily connected to the KVM device at that time.
680      */
681     CPU_FOREACH(cs) {
682         PowerPCCPU *cpu = POWERPC_CPU(cs);
683 
684         ret = kvmppc_xive_cpu_set_state(spapr_cpu_state(cpu)->tctx, &local_err);
685         if (ret < 0) {
686             goto fail;
687         }
688     }
689 
690     /* The source states will be restored when the machine starts running */
691     return 0;
692 
693 fail:
694     error_report_err(local_err);
695     return ret;
696 }
697 
698 /* Returns MAP_FAILED on error and sets errno */
kvmppc_xive_mmap(SpaprXive * xive,int pgoff,size_t len,Error ** errp)699 static void *kvmppc_xive_mmap(SpaprXive *xive, int pgoff, size_t len,
700                               Error **errp)
701 {
702     void *addr;
703     uint32_t page_shift = 16; /* TODO: fix page_shift */
704 
705     addr = mmap(NULL, len, PROT_WRITE | PROT_READ, MAP_SHARED, xive->fd,
706                 pgoff << page_shift);
707     if (addr == MAP_FAILED) {
708         error_setg_errno(errp, errno, "XIVE: unable to set memory mapping");
709     }
710 
711     return addr;
712 }
713 
714 /*
715  * All the XIVE memory regions are now backed by mappings from the KVM
716  * XIVE device.
717  */
kvmppc_xive_connect(SpaprInterruptController * intc,uint32_t nr_servers,Error ** errp)718 int kvmppc_xive_connect(SpaprInterruptController *intc, uint32_t nr_servers,
719                         Error **errp)
720 {
721     SpaprXive *xive = SPAPR_XIVE(intc);
722     XiveSource *xsrc = &xive->source;
723     uint64_t esb_len = xive_source_esb_len(xsrc);
724     size_t tima_len = 4ull << TM_SHIFT;
725     CPUState *cs;
726     int fd;
727     void *addr;
728     int ret;
729 
730     /*
731      * The KVM XIVE device already in use. This is the case when
732      * rebooting under the XIVE-only interrupt mode.
733      */
734     if (xive->fd != -1) {
735         return 0;
736     }
737 
738     if (!kvmppc_has_cap_xive()) {
739         error_setg(errp, "IRQ_XIVE capability must be present for KVM");
740         return -1;
741     }
742 
743     /* First, create the KVM XIVE device */
744     fd = kvm_create_device(kvm_state, KVM_DEV_TYPE_XIVE, false);
745     if (fd < 0) {
746         error_setg_errno(errp, -fd, "XIVE: error creating KVM device");
747         return -1;
748     }
749     xive->fd = fd;
750 
751     /* Tell KVM about the # of VCPUs we may have */
752     if (kvm_device_check_attr(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
753                               KVM_DEV_XIVE_NR_SERVERS)) {
754         ret = kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
755                                 KVM_DEV_XIVE_NR_SERVERS, &nr_servers, true,
756                                 errp);
757         if (ret < 0) {
758             goto fail;
759         }
760     }
761 
762     /*
763      * 1. Source ESB pages - KVM mapping
764      */
765     addr = kvmppc_xive_mmap(xive, KVM_XIVE_ESB_PAGE_OFFSET, esb_len, errp);
766     if (addr == MAP_FAILED) {
767         goto fail;
768     }
769     xsrc->esb_mmap = addr;
770 
771     memory_region_init_ram_device_ptr(&xsrc->esb_mmio_kvm, OBJECT(xsrc),
772                                       "xive.esb-kvm", esb_len, xsrc->esb_mmap);
773     memory_region_add_subregion_overlap(&xsrc->esb_mmio, 0,
774                                         &xsrc->esb_mmio_kvm, 1);
775 
776     /*
777      * 2. END ESB pages (No KVM support yet)
778      */
779 
780     /*
781      * 3. TIMA pages - KVM mapping
782      */
783     addr = kvmppc_xive_mmap(xive, KVM_XIVE_TIMA_PAGE_OFFSET, tima_len, errp);
784     if (addr == MAP_FAILED) {
785         goto fail;
786     }
787     xive->tm_mmap = addr;
788 
789     memory_region_init_ram_device_ptr(&xive->tm_mmio_kvm, OBJECT(xive),
790                                       "xive.tima", tima_len, xive->tm_mmap);
791     memory_region_add_subregion_overlap(&xive->tm_mmio, 0,
792                                         &xive->tm_mmio_kvm, 1);
793 
794     xive->change = qemu_add_vm_change_state_handler(
795         kvmppc_xive_change_state_handler, xive);
796 
797     /* Connect the presenters to the initial VCPUs of the machine */
798     CPU_FOREACH(cs) {
799         PowerPCCPU *cpu = POWERPC_CPU(cs);
800 
801         ret = kvmppc_xive_cpu_connect(spapr_cpu_state(cpu)->tctx, errp);
802         if (ret < 0) {
803             goto fail;
804         }
805     }
806 
807     /* Update the KVM sources */
808     ret = kvmppc_xive_source_reset(xsrc, errp);
809     if (ret < 0) {
810         goto fail;
811     }
812 
813     kvm_kernel_irqchip = true;
814     kvm_msi_via_irqfd_allowed = true;
815     kvm_gsi_direct_mapping = true;
816     return 0;
817 
818 fail:
819     kvmppc_xive_disconnect(intc);
820     return -1;
821 }
822 
kvmppc_xive_disconnect(SpaprInterruptController * intc)823 void kvmppc_xive_disconnect(SpaprInterruptController *intc)
824 {
825     SpaprXive *xive = SPAPR_XIVE(intc);
826     XiveSource *xsrc;
827     uint64_t esb_len;
828 
829     assert(xive->fd != -1);
830 
831     /* Clear the KVM mapping */
832     xsrc = &xive->source;
833     esb_len = xive_source_esb_len(xsrc);
834 
835     if (xsrc->esb_mmap) {
836         memory_region_del_subregion(&xsrc->esb_mmio, &xsrc->esb_mmio_kvm);
837         object_unparent(OBJECT(&xsrc->esb_mmio_kvm));
838         munmap(xsrc->esb_mmap, esb_len);
839         xsrc->esb_mmap = NULL;
840     }
841 
842     if (xive->tm_mmap) {
843         memory_region_del_subregion(&xive->tm_mmio, &xive->tm_mmio_kvm);
844         object_unparent(OBJECT(&xive->tm_mmio_kvm));
845         munmap(xive->tm_mmap, 4ull << TM_SHIFT);
846         xive->tm_mmap = NULL;
847     }
848 
849     /*
850      * When the KVM device fd is closed, the KVM device is destroyed
851      * and removed from the list of devices of the VM. The VCPU
852      * presenters are also detached from the device.
853      */
854     close(xive->fd);
855     xive->fd = -1;
856 
857     kvm_kernel_irqchip = false;
858     kvm_msi_via_irqfd_allowed = false;
859     kvm_gsi_direct_mapping = false;
860 
861     /* Clear the local list of presenter (hotplug) */
862     kvm_cpu_disable_all();
863 
864     /* VM Change state handler is not needed anymore */
865     if (xive->change) {
866         qemu_del_vm_change_state_handler(xive->change);
867         xive->change = NULL;
868     }
869 }
870