xref: /openbmc/qemu/hw/intc/spapr_xive_kvm.c (revision 46407a2531da4ff206c1aefe8c3f6d8ad53f2de4)
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 
24 #include <sys/ioctl.h>
25 
26 /*
27  * Helpers for CPU hotplug
28  *
29  * TODO: make a common KVMEnabledCPU layer for XICS and XIVE
30  */
31 typedef struct KVMEnabledCPU {
32     unsigned long vcpu_id;
33     QLIST_ENTRY(KVMEnabledCPU) node;
34 } KVMEnabledCPU;
35 
36 static QLIST_HEAD(, KVMEnabledCPU)
37     kvm_enabled_cpus = QLIST_HEAD_INITIALIZER(&kvm_enabled_cpus);
38 
39 static bool kvm_cpu_is_enabled(CPUState *cs)
40 {
41     KVMEnabledCPU *enabled_cpu;
42     unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
43 
44     QLIST_FOREACH(enabled_cpu, &kvm_enabled_cpus, node) {
45         if (enabled_cpu->vcpu_id == vcpu_id) {
46             return true;
47         }
48     }
49     return false;
50 }
51 
52 static void kvm_cpu_enable(CPUState *cs)
53 {
54     KVMEnabledCPU *enabled_cpu;
55     unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
56 
57     enabled_cpu = g_malloc(sizeof(*enabled_cpu));
58     enabled_cpu->vcpu_id = vcpu_id;
59     QLIST_INSERT_HEAD(&kvm_enabled_cpus, enabled_cpu, node);
60 }
61 
62 static void kvm_cpu_disable_all(void)
63 {
64     KVMEnabledCPU *enabled_cpu, *next;
65 
66     QLIST_FOREACH_SAFE(enabled_cpu, &kvm_enabled_cpus, node, next) {
67         QLIST_REMOVE(enabled_cpu, node);
68         g_free(enabled_cpu);
69     }
70 }
71 
72 /*
73  * XIVE Thread Interrupt Management context (KVM)
74  */
75 
76 void kvmppc_xive_cpu_set_state(XiveTCTX *tctx, Error **errp)
77 {
78     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
79     uint64_t state[2];
80     int ret;
81 
82     assert(xive->fd != -1);
83 
84     /* word0 and word1 of the OS ring. */
85     state[0] = *((uint64_t *) &tctx->regs[TM_QW1_OS]);
86 
87     ret = kvm_set_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
88     if (ret != 0) {
89         error_setg_errno(errp, errno,
90                          "XIVE: could not restore KVM state of CPU %ld",
91                          kvm_arch_vcpu_id(tctx->cs));
92     }
93 }
94 
95 void kvmppc_xive_cpu_get_state(XiveTCTX *tctx, Error **errp)
96 {
97     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
98     uint64_t state[2] = { 0 };
99     int ret;
100 
101     assert(xive->fd != -1);
102 
103     ret = kvm_get_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
104     if (ret != 0) {
105         error_setg_errno(errp, errno,
106                          "XIVE: could not capture KVM state of CPU %ld",
107                          kvm_arch_vcpu_id(tctx->cs));
108         return;
109     }
110 
111     /* word0 and word1 of the OS ring. */
112     *((uint64_t *) &tctx->regs[TM_QW1_OS]) = state[0];
113 }
114 
115 typedef struct {
116     XiveTCTX *tctx;
117     Error *err;
118 } XiveCpuGetState;
119 
120 static void kvmppc_xive_cpu_do_synchronize_state(CPUState *cpu,
121                                                  run_on_cpu_data arg)
122 {
123     XiveCpuGetState *s = arg.host_ptr;
124 
125     kvmppc_xive_cpu_get_state(s->tctx, &s->err);
126 }
127 
128 void kvmppc_xive_cpu_synchronize_state(XiveTCTX *tctx, Error **errp)
129 {
130     XiveCpuGetState s = {
131         .tctx = tctx,
132         .err = NULL,
133     };
134 
135     /*
136      * Kick the vCPU to make sure they are available for the KVM ioctl.
137      */
138     run_on_cpu(tctx->cs, kvmppc_xive_cpu_do_synchronize_state,
139                RUN_ON_CPU_HOST_PTR(&s));
140 
141     if (s.err) {
142         error_propagate(errp, s.err);
143         return;
144     }
145 }
146 
147 int kvmppc_xive_cpu_connect(XiveTCTX *tctx, Error **errp)
148 {
149     ERRP_GUARD();
150     SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
151     unsigned long vcpu_id;
152     int ret;
153 
154     assert(xive->fd != -1);
155 
156     /* Check if CPU was hot unplugged and replugged. */
157     if (kvm_cpu_is_enabled(tctx->cs)) {
158         return 0;
159     }
160 
161     vcpu_id = kvm_arch_vcpu_id(tctx->cs);
162 
163     ret = kvm_vcpu_enable_cap(tctx->cs, KVM_CAP_PPC_IRQ_XIVE, 0, xive->fd,
164                               vcpu_id, 0);
165     if (ret < 0) {
166         error_setg_errno(errp, -ret,
167                          "XIVE: unable to connect CPU%ld to KVM device",
168                          vcpu_id);
169         if (ret == -ENOSPC) {
170             error_append_hint(errp, "Try -smp maxcpus=N with N < %u\n",
171                               MACHINE(qdev_get_machine())->smp.max_cpus);
172         }
173         return ret;
174     }
175 
176     kvm_cpu_enable(tctx->cs);
177     return 0;
178 }
179 
180 /*
181  * XIVE Interrupt Source (KVM)
182  */
183 
184 void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
185                                    Error **errp)
186 {
187     uint32_t end_idx;
188     uint32_t end_blk;
189     uint8_t priority;
190     uint32_t server;
191     bool masked;
192     uint32_t eisn;
193     uint64_t kvm_src;
194     Error *local_err = NULL;
195 
196     assert(xive_eas_is_valid(eas));
197 
198     end_idx = xive_get_field64(EAS_END_INDEX, eas->w);
199     end_blk = xive_get_field64(EAS_END_BLOCK, eas->w);
200     eisn = xive_get_field64(EAS_END_DATA, eas->w);
201     masked = xive_eas_is_masked(eas);
202 
203     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
204 
205     kvm_src = priority << KVM_XIVE_SOURCE_PRIORITY_SHIFT &
206         KVM_XIVE_SOURCE_PRIORITY_MASK;
207     kvm_src |= server << KVM_XIVE_SOURCE_SERVER_SHIFT &
208         KVM_XIVE_SOURCE_SERVER_MASK;
209     kvm_src |= ((uint64_t) masked << KVM_XIVE_SOURCE_MASKED_SHIFT) &
210         KVM_XIVE_SOURCE_MASKED_MASK;
211     kvm_src |= ((uint64_t)eisn << KVM_XIVE_SOURCE_EISN_SHIFT) &
212         KVM_XIVE_SOURCE_EISN_MASK;
213 
214     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_CONFIG, lisn,
215                       &kvm_src, true, &local_err);
216     if (local_err) {
217         error_propagate(errp, local_err);
218         return;
219     }
220 }
221 
222 void kvmppc_xive_sync_source(SpaprXive *xive, uint32_t lisn, Error **errp)
223 {
224     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_SYNC, lisn,
225                       NULL, true, errp);
226 }
227 
228 /*
229  * At reset, the interrupt sources are simply created and MASKED. We
230  * only need to inform the KVM XIVE device about their type: LSI or
231  * MSI.
232  */
233 int kvmppc_xive_source_reset_one(XiveSource *xsrc, int srcno, Error **errp)
234 {
235     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
236     uint64_t state = 0;
237 
238     assert(xive->fd != -1);
239 
240     if (xive_source_irq_is_lsi(xsrc, srcno)) {
241         state |= KVM_XIVE_LEVEL_SENSITIVE;
242         if (xsrc->status[srcno] & XIVE_STATUS_ASSERTED) {
243             state |= KVM_XIVE_LEVEL_ASSERTED;
244         }
245     }
246 
247     return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE, srcno, &state,
248                              true, errp);
249 }
250 
251 static int kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
252 {
253     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
254     int i;
255 
256     for (i = 0; i < xsrc->nr_irqs; i++) {
257         int ret;
258 
259         if (!xive_eas_is_valid(&xive->eat[i])) {
260             continue;
261         }
262 
263         ret = kvmppc_xive_source_reset_one(xsrc, i, errp);
264         if (ret < 0) {
265             return ret;
266         }
267     }
268 
269     return 0;
270 }
271 
272 /*
273  * This is used to perform the magic loads on the ESB pages, described
274  * in xive.h.
275  *
276  * Memory barriers should not be needed for loads (no store for now).
277  */
278 static uint64_t xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
279                             uint64_t data, bool write)
280 {
281     uint64_t *addr = xsrc->esb_mmap + xive_source_esb_mgmt(xsrc, srcno) +
282         offset;
283 
284     if (write) {
285         *addr = cpu_to_be64(data);
286         return -1;
287     } else {
288         /* Prevent the compiler from optimizing away the load */
289         volatile uint64_t value = be64_to_cpu(*addr);
290         return value;
291     }
292 }
293 
294 static uint8_t xive_esb_read(XiveSource *xsrc, int srcno, uint32_t offset)
295 {
296     return xive_esb_rw(xsrc, srcno, offset, 0, 0) & 0x3;
297 }
298 
299 static void xive_esb_trigger(XiveSource *xsrc, int srcno)
300 {
301     uint64_t *addr = xsrc->esb_mmap + xive_source_esb_page(xsrc, srcno);
302 
303     *addr = 0x0;
304 }
305 
306 uint64_t kvmppc_xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
307                             uint64_t data, bool write)
308 {
309     if (write) {
310         return xive_esb_rw(xsrc, srcno, offset, data, 1);
311     }
312 
313     /*
314      * Special Load EOI handling for LSI sources. Q bit is never set
315      * and the interrupt should be re-triggered if the level is still
316      * asserted.
317      */
318     if (xive_source_irq_is_lsi(xsrc, srcno) &&
319         offset == XIVE_ESB_LOAD_EOI) {
320         xive_esb_read(xsrc, srcno, XIVE_ESB_SET_PQ_00);
321         if (xsrc->status[srcno] & XIVE_STATUS_ASSERTED) {
322             xive_esb_trigger(xsrc, srcno);
323         }
324         return 0;
325     } else {
326         return xive_esb_rw(xsrc, srcno, offset, 0, 0);
327     }
328 }
329 
330 static void kvmppc_xive_source_get_state(XiveSource *xsrc)
331 {
332     SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
333     int i;
334 
335     for (i = 0; i < xsrc->nr_irqs; i++) {
336         uint8_t pq;
337 
338         if (!xive_eas_is_valid(&xive->eat[i])) {
339             continue;
340         }
341 
342         /* Perform a load without side effect to retrieve the PQ bits */
343         pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
344 
345         /* and save PQ locally */
346         xive_source_esb_set(xsrc, i, pq);
347     }
348 }
349 
350 void kvmppc_xive_source_set_irq(void *opaque, int srcno, int val)
351 {
352     XiveSource *xsrc = opaque;
353 
354     if (!xive_source_irq_is_lsi(xsrc, srcno)) {
355         if (!val) {
356             return;
357         }
358     } else {
359         if (val) {
360             xsrc->status[srcno] |= XIVE_STATUS_ASSERTED;
361         } else {
362             xsrc->status[srcno] &= ~XIVE_STATUS_ASSERTED;
363         }
364     }
365 
366     xive_esb_trigger(xsrc, srcno);
367 }
368 
369 /*
370  * sPAPR XIVE interrupt controller (KVM)
371  */
372 void kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
373                                   uint32_t end_idx, XiveEND *end,
374                                   Error **errp)
375 {
376     struct kvm_ppc_xive_eq kvm_eq = { 0 };
377     uint64_t kvm_eq_idx;
378     uint8_t priority;
379     uint32_t server;
380     Error *local_err = NULL;
381 
382     assert(xive_end_is_valid(end));
383 
384     /* Encode the tuple (server, prio) as a KVM EQ index */
385     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
386 
387     kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
388             KVM_XIVE_EQ_PRIORITY_MASK;
389     kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
390         KVM_XIVE_EQ_SERVER_MASK;
391 
392     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
393                       &kvm_eq, false, &local_err);
394     if (local_err) {
395         error_propagate(errp, local_err);
396         return;
397     }
398 
399     /*
400      * The EQ index and toggle bit are updated by HW. These are the
401      * only fields from KVM we want to update QEMU with. The other END
402      * fields should already be in the QEMU END table.
403      */
404     end->w1 = xive_set_field32(END_W1_GENERATION, 0ul, kvm_eq.qtoggle) |
405         xive_set_field32(END_W1_PAGE_OFF, 0ul, kvm_eq.qindex);
406 }
407 
408 void kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
409                                   uint32_t end_idx, XiveEND *end,
410                                   Error **errp)
411 {
412     struct kvm_ppc_xive_eq kvm_eq = { 0 };
413     uint64_t kvm_eq_idx;
414     uint8_t priority;
415     uint32_t server;
416     Error *local_err = NULL;
417 
418     /*
419      * Build the KVM state from the local END structure.
420      */
421 
422     kvm_eq.flags = 0;
423     if (xive_get_field32(END_W0_UCOND_NOTIFY, end->w0)) {
424         kvm_eq.flags |= KVM_XIVE_EQ_ALWAYS_NOTIFY;
425     }
426 
427     /*
428      * If the hcall is disabling the EQ, set the size and page address
429      * to zero. When migrating, only valid ENDs are taken into
430      * account.
431      */
432     if (xive_end_is_valid(end)) {
433         kvm_eq.qshift = xive_get_field32(END_W0_QSIZE, end->w0) + 12;
434         kvm_eq.qaddr  = xive_end_qaddr(end);
435         /*
436          * The EQ toggle bit and index should only be relevant when
437          * restoring the EQ state
438          */
439         kvm_eq.qtoggle = xive_get_field32(END_W1_GENERATION, end->w1);
440         kvm_eq.qindex  = xive_get_field32(END_W1_PAGE_OFF, end->w1);
441     } else {
442         kvm_eq.qshift = 0;
443         kvm_eq.qaddr  = 0;
444     }
445 
446     /* Encode the tuple (server, prio) as a KVM EQ index */
447     spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
448 
449     kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
450             KVM_XIVE_EQ_PRIORITY_MASK;
451     kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
452         KVM_XIVE_EQ_SERVER_MASK;
453 
454     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
455                       &kvm_eq, true, &local_err);
456     if (local_err) {
457         error_propagate(errp, local_err);
458         return;
459     }
460 }
461 
462 void kvmppc_xive_reset(SpaprXive *xive, Error **errp)
463 {
464     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL, KVM_DEV_XIVE_RESET,
465                       NULL, true, errp);
466 }
467 
468 static void kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
469 {
470     Error *local_err = NULL;
471     int i;
472 
473     for (i = 0; i < xive->nr_ends; i++) {
474         if (!xive_end_is_valid(&xive->endt[i])) {
475             continue;
476         }
477 
478         kvmppc_xive_get_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
479                                      &xive->endt[i], &local_err);
480         if (local_err) {
481             error_propagate(errp, local_err);
482             return;
483         }
484     }
485 }
486 
487 /*
488  * The primary goal of the XIVE VM change handler is to mark the EQ
489  * pages dirty when all XIVE event notifications have stopped.
490  *
491  * Whenever the VM is stopped, the VM change handler sets the source
492  * PQs to PENDING to stop the flow of events and to possibly catch a
493  * triggered interrupt occuring while the VM is stopped. The previous
494  * state is saved in anticipation of a migration. The XIVE controller
495  * is then synced through KVM to flush any in-flight event
496  * notification and stabilize the EQs.
497  *
498  * At this stage, we can mark the EQ page dirty and let a migration
499  * sequence transfer the EQ pages to the destination, which is done
500  * just after the stop state.
501  *
502  * The previous configuration of the sources is restored when the VM
503  * runs again. If an interrupt was queued while the VM was stopped,
504  * simply generate a trigger.
505  */
506 static void kvmppc_xive_change_state_handler(void *opaque, int running,
507                                              RunState state)
508 {
509     SpaprXive *xive = opaque;
510     XiveSource *xsrc = &xive->source;
511     Error *local_err = NULL;
512     int i;
513 
514     /*
515      * Restore the sources to their initial state. This is called when
516      * the VM resumes after a stop or a migration.
517      */
518     if (running) {
519         for (i = 0; i < xsrc->nr_irqs; i++) {
520             uint8_t pq;
521             uint8_t old_pq;
522 
523             if (!xive_eas_is_valid(&xive->eat[i])) {
524                 continue;
525             }
526 
527             pq = xive_source_esb_get(xsrc, i);
528             old_pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_00 + (pq << 8));
529 
530             /*
531              * An interrupt was queued while the VM was stopped,
532              * generate a trigger.
533              */
534             if (pq == XIVE_ESB_RESET && old_pq == XIVE_ESB_QUEUED) {
535                 xive_esb_trigger(xsrc, i);
536             }
537         }
538 
539         return;
540     }
541 
542     /*
543      * Mask the sources, to stop the flow of event notifications, and
544      * save the PQs locally in the XiveSource object. The XiveSource
545      * state will be collected later on by its vmstate handler if a
546      * migration is in progress.
547      */
548     for (i = 0; i < xsrc->nr_irqs; i++) {
549         uint8_t pq;
550 
551         if (!xive_eas_is_valid(&xive->eat[i])) {
552             continue;
553         }
554 
555         pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
556 
557         /*
558          * PQ is set to PENDING to possibly catch a triggered
559          * interrupt occuring while the VM is stopped (hotplug event
560          * for instance) .
561          */
562         if (pq != XIVE_ESB_OFF) {
563             pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_10);
564         }
565         xive_source_esb_set(xsrc, i, pq);
566     }
567 
568     /*
569      * Sync the XIVE controller in KVM, to flush in-flight event
570      * notification that should be enqueued in the EQs and mark the
571      * XIVE EQ pages dirty to collect all updates.
572      */
573     kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
574                       KVM_DEV_XIVE_EQ_SYNC, NULL, true, &local_err);
575     if (local_err) {
576         error_report_err(local_err);
577         return;
578     }
579 }
580 
581 void kvmppc_xive_synchronize_state(SpaprXive *xive, Error **errp)
582 {
583     assert(xive->fd != -1);
584 
585     /*
586      * When the VM is stopped, the sources are masked and the previous
587      * state is saved in anticipation of a migration. We should not
588      * synchronize the source state in that case else we will override
589      * the saved state.
590      */
591     if (runstate_is_running()) {
592         kvmppc_xive_source_get_state(&xive->source);
593     }
594 
595     /* EAT: there is no extra state to query from KVM */
596 
597     /* ENDT */
598     kvmppc_xive_get_queues(xive, errp);
599 }
600 
601 /*
602  * The SpaprXive 'pre_save' method is called by the vmstate handler of
603  * the SpaprXive model, after the XIVE controller is synced in the VM
604  * change handler.
605  */
606 int kvmppc_xive_pre_save(SpaprXive *xive)
607 {
608     Error *local_err = NULL;
609 
610     assert(xive->fd != -1);
611 
612     /* EAT: there is no extra state to query from KVM */
613 
614     /* ENDT */
615     kvmppc_xive_get_queues(xive, &local_err);
616     if (local_err) {
617         error_report_err(local_err);
618         return -1;
619     }
620 
621     return 0;
622 }
623 
624 /*
625  * The SpaprXive 'post_load' method is not called by a vmstate
626  * handler. It is called at the sPAPR machine level at the end of the
627  * migration sequence by the sPAPR IRQ backend 'post_load' method,
628  * when all XIVE states have been transferred and loaded.
629  */
630 int kvmppc_xive_post_load(SpaprXive *xive, int version_id)
631 {
632     Error *local_err = NULL;
633     CPUState *cs;
634     int i;
635 
636     /* The KVM XIVE device should be in use */
637     assert(xive->fd != -1);
638 
639     /* Restore the ENDT first. The targetting depends on it. */
640     for (i = 0; i < xive->nr_ends; i++) {
641         if (!xive_end_is_valid(&xive->endt[i])) {
642             continue;
643         }
644 
645         kvmppc_xive_set_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
646                                      &xive->endt[i], &local_err);
647         if (local_err) {
648             error_report_err(local_err);
649             return -1;
650         }
651     }
652 
653     /* Restore the EAT */
654     for (i = 0; i < xive->nr_irqs; i++) {
655         if (!xive_eas_is_valid(&xive->eat[i])) {
656             continue;
657         }
658 
659         /*
660          * We can only restore the source config if the source has been
661          * previously set in KVM. Since we don't do that for all interrupts
662          * at reset time anymore, let's do it now.
663          */
664         kvmppc_xive_source_reset_one(&xive->source, i, &local_err);
665         if (local_err) {
666             error_report_err(local_err);
667             return -1;
668         }
669 
670         kvmppc_xive_set_source_config(xive, i, &xive->eat[i], &local_err);
671         if (local_err) {
672             error_report_err(local_err);
673             return -1;
674         }
675     }
676 
677     /*
678      * Restore the thread interrupt contexts of initial CPUs.
679      *
680      * The context of hotplugged CPUs is restored later, by the
681      * 'post_load' handler of the XiveTCTX model because they are not
682      * available at the time the SpaprXive 'post_load' method is
683      * called. We can not restore the context of all CPUs in the
684      * 'post_load' handler of XiveTCTX because the machine is not
685      * necessarily connected to the KVM device at that time.
686      */
687     CPU_FOREACH(cs) {
688         PowerPCCPU *cpu = POWERPC_CPU(cs);
689 
690         kvmppc_xive_cpu_set_state(spapr_cpu_state(cpu)->tctx, &local_err);
691         if (local_err) {
692             error_report_err(local_err);
693             return -1;
694         }
695     }
696 
697     /* The source states will be restored when the machine starts running */
698     return 0;
699 }
700 
701 static void *kvmppc_xive_mmap(SpaprXive *xive, int pgoff, size_t len,
702                               Error **errp)
703 {
704     void *addr;
705     uint32_t page_shift = 16; /* TODO: fix page_shift */
706 
707     addr = mmap(NULL, len, PROT_WRITE | PROT_READ, MAP_SHARED, xive->fd,
708                 pgoff << page_shift);
709     if (addr == MAP_FAILED) {
710         error_setg_errno(errp, errno, "XIVE: unable to set memory mapping");
711         return NULL;
712     }
713 
714     return addr;
715 }
716 
717 /*
718  * All the XIVE memory regions are now backed by mappings from the KVM
719  * XIVE device.
720  */
721 int kvmppc_xive_connect(SpaprInterruptController *intc, uint32_t nr_servers,
722                         Error **errp)
723 {
724     SpaprXive *xive = SPAPR_XIVE(intc);
725     XiveSource *xsrc = &xive->source;
726     Error *local_err = NULL;
727     size_t esb_len = xive_source_esb_len(xsrc);
728     size_t tima_len = 4ull << TM_SHIFT;
729     CPUState *cs;
730     int fd;
731 
732     /*
733      * The KVM XIVE device already in use. This is the case when
734      * rebooting under the XIVE-only interrupt mode.
735      */
736     if (xive->fd != -1) {
737         return 0;
738     }
739 
740     if (!kvmppc_has_cap_xive()) {
741         error_setg(errp, "IRQ_XIVE capability must be present for KVM");
742         return -1;
743     }
744 
745     /* First, create the KVM XIVE device */
746     fd = kvm_create_device(kvm_state, KVM_DEV_TYPE_XIVE, false);
747     if (fd < 0) {
748         error_setg_errno(errp, -fd, "XIVE: error creating KVM device");
749         return -1;
750     }
751     xive->fd = fd;
752 
753     /* Tell KVM about the # of VCPUs we may have */
754     if (kvm_device_check_attr(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
755                               KVM_DEV_XIVE_NR_SERVERS)) {
756         if (kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
757                               KVM_DEV_XIVE_NR_SERVERS, &nr_servers, true,
758                               &local_err)) {
759             goto fail;
760         }
761     }
762 
763     /*
764      * 1. Source ESB pages - KVM mapping
765      */
766     xsrc->esb_mmap = kvmppc_xive_mmap(xive, KVM_XIVE_ESB_PAGE_OFFSET, esb_len,
767                                       &local_err);
768     if (local_err) {
769         goto fail;
770     }
771 
772     memory_region_init_ram_device_ptr(&xsrc->esb_mmio_kvm, OBJECT(xsrc),
773                                       "xive.esb-kvm", esb_len, xsrc->esb_mmap);
774     memory_region_add_subregion_overlap(&xsrc->esb_mmio, 0,
775                                         &xsrc->esb_mmio_kvm, 1);
776 
777     /*
778      * 2. END ESB pages (No KVM support yet)
779      */
780 
781     /*
782      * 3. TIMA pages - KVM mapping
783      */
784     xive->tm_mmap = kvmppc_xive_mmap(xive, KVM_XIVE_TIMA_PAGE_OFFSET, tima_len,
785                                      &local_err);
786     if (local_err) {
787         goto fail;
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         kvmppc_xive_cpu_connect(spapr_cpu_state(cpu)->tctx, &local_err);
802         if (local_err) {
803             goto fail;
804         }
805     }
806 
807     /* Update the KVM sources */
808     kvmppc_xive_source_reset(xsrc, &local_err);
809     if (local_err) {
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     error_propagate(errp, local_err);
820     kvmppc_xive_disconnect(intc);
821     return -1;
822 }
823 
824 void kvmppc_xive_disconnect(SpaprInterruptController *intc)
825 {
826     SpaprXive *xive = SPAPR_XIVE(intc);
827     XiveSource *xsrc;
828     size_t esb_len;
829 
830     assert(xive->fd != -1);
831 
832     /* Clear the KVM mapping */
833     xsrc = &xive->source;
834     esb_len = (1ull << xsrc->esb_shift) * xsrc->nr_irqs;
835 
836     if (xsrc->esb_mmap) {
837         memory_region_del_subregion(&xsrc->esb_mmio, &xsrc->esb_mmio_kvm);
838         object_unparent(OBJECT(&xsrc->esb_mmio_kvm));
839         munmap(xsrc->esb_mmap, esb_len);
840         xsrc->esb_mmap = NULL;
841     }
842 
843     if (xive->tm_mmap) {
844         memory_region_del_subregion(&xive->tm_mmio, &xive->tm_mmio_kvm);
845         object_unparent(OBJECT(&xive->tm_mmio_kvm));
846         munmap(xive->tm_mmap, 4ull << TM_SHIFT);
847         xive->tm_mmap = NULL;
848     }
849 
850     /*
851      * When the KVM device fd is closed, the KVM device is destroyed
852      * and removed from the list of devices of the VM. The VCPU
853      * presenters are also detached from the device.
854      */
855     close(xive->fd);
856     xive->fd = -1;
857 
858     kvm_kernel_irqchip = false;
859     kvm_msi_via_irqfd_allowed = false;
860     kvm_gsi_direct_mapping = false;
861 
862     /* Clear the local list of presenter (hotplug) */
863     kvm_cpu_disable_all();
864 
865     /* VM Change state handler is not needed anymore */
866     if (xive->change) {
867         qemu_del_vm_change_state_handler(xive->change);
868         xive->change = NULL;
869     }
870 }
871