xref: /openbmc/qemu/hw/vfio/ccw.c (revision 21063bce)
1 /*
2  * vfio based subchannel assignment support
3  *
4  * Copyright 2017 IBM Corp.
5  * Copyright 2019 Red Hat, Inc.
6  *
7  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
8  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
9  *            Pierre Morel <pmorel@linux.vnet.ibm.com>
10  *            Cornelia Huck <cohuck@redhat.com>
11  *
12  * This work is licensed under the terms of the GNU GPL, version 2 or (at
13  * your option) any later version. See the COPYING file in the top-level
14  * directory.
15  */
16 
17 #include "qemu/osdep.h"
18 #include <linux/vfio.h>
19 #include <linux/vfio_ccw.h>
20 #include <sys/ioctl.h>
21 
22 #include "qapi/error.h"
23 #include "hw/vfio/vfio.h"
24 #include "hw/vfio/vfio-common.h"
25 #include "hw/s390x/s390-ccw.h"
26 #include "hw/s390x/vfio-ccw.h"
27 #include "hw/qdev-properties.h"
28 #include "hw/s390x/ccw-device.h"
29 #include "exec/address-spaces.h"
30 #include "qemu/error-report.h"
31 #include "qemu/main-loop.h"
32 #include "qemu/module.h"
33 
34 struct VFIOCCWDevice {
35     S390CCWDevice cdev;
36     VFIODevice vdev;
37     uint64_t io_region_size;
38     uint64_t io_region_offset;
39     struct ccw_io_region *io_region;
40     uint64_t async_cmd_region_size;
41     uint64_t async_cmd_region_offset;
42     struct ccw_cmd_region *async_cmd_region;
43     uint64_t schib_region_size;
44     uint64_t schib_region_offset;
45     struct ccw_schib_region *schib_region;
46     uint64_t crw_region_size;
47     uint64_t crw_region_offset;
48     struct ccw_crw_region *crw_region;
49     EventNotifier io_notifier;
50     EventNotifier crw_notifier;
51     EventNotifier req_notifier;
52     bool force_orb_pfch;
53     bool warned_orb_pfch;
54 };
55 
56 static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch,
57                                   const char *msg)
58 {
59     warn_report_once_cond(&vcdev->warned_orb_pfch,
60                           "vfio-ccw (devno %x.%x.%04x): %s",
61                           sch->cssid, sch->ssid, sch->devno, msg);
62 }
63 
64 static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
65 {
66     vdev->needs_reset = false;
67 }
68 
69 /*
70  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
71  * vfio_ccw device now.
72  */
73 struct VFIODeviceOps vfio_ccw_ops = {
74     .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
75 };
76 
77 static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
78 {
79     VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
80     struct ccw_io_region *region = vcdev->io_region;
81     int ret;
82 
83     if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) {
84         sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH;
85         warn_once_pfch(vcdev, sch, "PFCH flag forced");
86     }
87 
88     QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
89     QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
90     QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
91 
92     memset(region, 0, sizeof(*region));
93 
94     memcpy(region->orb_area, &sch->orb, sizeof(ORB));
95     memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
96 
97 again:
98     ret = pwrite(vcdev->vdev.fd, region,
99                  vcdev->io_region_size, vcdev->io_region_offset);
100     if (ret != vcdev->io_region_size) {
101         if (errno == EAGAIN) {
102             goto again;
103         }
104         error_report("vfio-ccw: write I/O region failed with errno=%d", errno);
105         ret = errno ? -errno : -EFAULT;
106     } else {
107         ret = 0;
108     }
109     switch (ret) {
110     case 0:
111         return IOINST_CC_EXPECTED;
112     case -EBUSY:
113         return IOINST_CC_BUSY;
114     case -ENODEV:
115     case -EACCES:
116         return IOINST_CC_NOT_OPERATIONAL;
117     case -EFAULT:
118     default:
119         sch_gen_unit_exception(sch);
120         css_inject_io_interrupt(sch);
121         return IOINST_CC_EXPECTED;
122     }
123 }
124 
125 static IOInstEnding vfio_ccw_handle_store(SubchDev *sch)
126 {
127     VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
128     SCHIB *schib = &sch->curr_status;
129     struct ccw_schib_region *region = vcdev->schib_region;
130     SCHIB *s;
131     int ret;
132 
133     /* schib region not available so nothing else to do */
134     if (!region) {
135         return IOINST_CC_EXPECTED;
136     }
137 
138     memset(region, 0, sizeof(*region));
139     ret = pread(vcdev->vdev.fd, region, vcdev->schib_region_size,
140                 vcdev->schib_region_offset);
141 
142     if (ret == -1) {
143         /*
144          * Device is probably damaged, but store subchannel does not
145          * have a nonzero cc defined for this scenario.  Log an error,
146          * and presume things are otherwise fine.
147          */
148         error_report("vfio-ccw: store region read failed with errno=%d", errno);
149         return IOINST_CC_EXPECTED;
150     }
151 
152     /*
153      * Selectively copy path-related bits of the SCHIB,
154      * rather than copying the entire struct.
155      */
156     s = (SCHIB *)region->schib_area;
157     schib->pmcw.pnom = s->pmcw.pnom;
158     schib->pmcw.lpum = s->pmcw.lpum;
159     schib->pmcw.pam = s->pmcw.pam;
160     schib->pmcw.pom = s->pmcw.pom;
161 
162     if (s->scsw.flags & SCSW_FLAGS_MASK_PNO) {
163         schib->scsw.flags |= SCSW_FLAGS_MASK_PNO;
164     }
165 
166     return IOINST_CC_EXPECTED;
167 }
168 
169 static int vfio_ccw_handle_clear(SubchDev *sch)
170 {
171     VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
172     struct ccw_cmd_region *region = vcdev->async_cmd_region;
173     int ret;
174 
175     if (!vcdev->async_cmd_region) {
176         /* Async command region not available, fall back to emulation */
177         return -ENOSYS;
178     }
179 
180     memset(region, 0, sizeof(*region));
181     region->command = VFIO_CCW_ASYNC_CMD_CSCH;
182 
183 again:
184     ret = pwrite(vcdev->vdev.fd, region,
185                  vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
186     if (ret != vcdev->async_cmd_region_size) {
187         if (errno == EAGAIN) {
188             goto again;
189         }
190         error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
191         ret = errno ? -errno : -EFAULT;
192     } else {
193         ret = 0;
194     }
195     switch (ret) {
196     case 0:
197     case -ENODEV:
198     case -EACCES:
199         return ret;
200     case -EFAULT:
201     default:
202         sch_gen_unit_exception(sch);
203         css_inject_io_interrupt(sch);
204         return 0;
205     }
206 }
207 
208 static int vfio_ccw_handle_halt(SubchDev *sch)
209 {
210     VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
211     struct ccw_cmd_region *region = vcdev->async_cmd_region;
212     int ret;
213 
214     if (!vcdev->async_cmd_region) {
215         /* Async command region not available, fall back to emulation */
216         return -ENOSYS;
217     }
218 
219     memset(region, 0, sizeof(*region));
220     region->command = VFIO_CCW_ASYNC_CMD_HSCH;
221 
222 again:
223     ret = pwrite(vcdev->vdev.fd, region,
224                  vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
225     if (ret != vcdev->async_cmd_region_size) {
226         if (errno == EAGAIN) {
227             goto again;
228         }
229         error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
230         ret = errno ? -errno : -EFAULT;
231     } else {
232         ret = 0;
233     }
234     switch (ret) {
235     case 0:
236     case -EBUSY:
237     case -ENODEV:
238     case -EACCES:
239         return ret;
240     case -EFAULT:
241     default:
242         sch_gen_unit_exception(sch);
243         css_inject_io_interrupt(sch);
244         return 0;
245     }
246 }
247 
248 static void vfio_ccw_reset(DeviceState *dev)
249 {
250     VFIOCCWDevice *vcdev = VFIO_CCW(dev);
251 
252     ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
253 }
254 
255 static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
256 {
257     struct ccw_crw_region *region = vcdev->crw_region;
258     CRW crw;
259     int size;
260 
261     /* Keep reading CRWs as long as data is returned */
262     do {
263         memset(region, 0, sizeof(*region));
264         size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size,
265                      vcdev->crw_region_offset);
266 
267         if (size == -1) {
268             error_report("vfio-ccw: Read crw region failed with errno=%d",
269                          errno);
270             break;
271         }
272 
273         if (region->crw == 0) {
274             /* No more CRWs to queue */
275             break;
276         }
277 
278         memcpy(&crw, &region->crw, sizeof(CRW));
279 
280         css_crw_add_to_queue(crw);
281     } while (1);
282 }
283 
284 static void vfio_ccw_req_notifier_handler(void *opaque)
285 {
286     VFIOCCWDevice *vcdev = opaque;
287     Error *err = NULL;
288 
289     if (!event_notifier_test_and_clear(&vcdev->req_notifier)) {
290         return;
291     }
292 
293     qdev_unplug(DEVICE(vcdev), &err);
294     if (err) {
295         warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
296     }
297 }
298 
299 static void vfio_ccw_crw_notifier_handler(void *opaque)
300 {
301     VFIOCCWDevice *vcdev = opaque;
302 
303     while (event_notifier_test_and_clear(&vcdev->crw_notifier)) {
304         vfio_ccw_crw_read(vcdev);
305     }
306 }
307 
308 static void vfio_ccw_io_notifier_handler(void *opaque)
309 {
310     VFIOCCWDevice *vcdev = opaque;
311     struct ccw_io_region *region = vcdev->io_region;
312     CcwDevice *ccw_dev = CCW_DEVICE(vcdev);
313     SubchDev *sch = ccw_dev->sch;
314     SCHIB *schib = &sch->curr_status;
315     SCSW s;
316     IRB irb;
317     ESW esw;
318     int size;
319 
320     if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
321         return;
322     }
323 
324     size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
325                  vcdev->io_region_offset);
326     if (size == -1) {
327         switch (errno) {
328         case ENODEV:
329             /* Generate a deferred cc 3 condition. */
330             schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
331             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
332             schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
333             goto read_err;
334         case EFAULT:
335             /* Memory problem, generate channel data check. */
336             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
337             schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK;
338             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
339             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
340                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
341             goto read_err;
342         default:
343             /* Error, generate channel program check. */
344             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
345             schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
346             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
347             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
348                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
349             goto read_err;
350         }
351     } else if (size != vcdev->io_region_size) {
352         /* Information transfer error, generate channel-control check. */
353         schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
354         schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK;
355         schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
356         schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
357                    SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
358         goto read_err;
359     }
360 
361     memcpy(&irb, region->irb_area, sizeof(IRB));
362 
363     /* Update control block via irb. */
364     s = schib->scsw;
365     copy_scsw_to_guest(&s, &irb.scsw);
366     schib->scsw = s;
367 
368     copy_esw_to_guest(&esw, &irb.esw);
369     sch->esw = esw;
370 
371     /* If a uint check is pending, copy sense data. */
372     if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
373         (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
374         memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
375     }
376 
377 read_err:
378     css_inject_io_interrupt(sch);
379 }
380 
381 static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
382                                            unsigned int irq,
383                                            Error **errp)
384 {
385     VFIODevice *vdev = &vcdev->vdev;
386     struct vfio_irq_info *irq_info;
387     size_t argsz;
388     int fd;
389     EventNotifier *notifier;
390     IOHandler *fd_read;
391 
392     switch (irq) {
393     case VFIO_CCW_IO_IRQ_INDEX:
394         notifier = &vcdev->io_notifier;
395         fd_read = vfio_ccw_io_notifier_handler;
396         break;
397     case VFIO_CCW_CRW_IRQ_INDEX:
398         notifier = &vcdev->crw_notifier;
399         fd_read = vfio_ccw_crw_notifier_handler;
400         break;
401     case VFIO_CCW_REQ_IRQ_INDEX:
402         notifier = &vcdev->req_notifier;
403         fd_read = vfio_ccw_req_notifier_handler;
404         break;
405     default:
406         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
407         return;
408     }
409 
410     if (vdev->num_irqs < irq + 1) {
411         error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
412                    irq, vdev->num_irqs);
413         return;
414     }
415 
416     argsz = sizeof(*irq_info);
417     irq_info = g_malloc0(argsz);
418     irq_info->index = irq;
419     irq_info->argsz = argsz;
420     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
421               irq_info) < 0 || irq_info->count < 1) {
422         error_setg_errno(errp, errno, "vfio: Error getting irq info");
423         goto out_free_info;
424     }
425 
426     if (event_notifier_init(notifier, 0)) {
427         error_setg_errno(errp, errno,
428                          "vfio: Unable to init event notifier for irq (%d)",
429                          irq);
430         goto out_free_info;
431     }
432 
433     fd = event_notifier_get_fd(notifier);
434     qemu_set_fd_handler(fd, fd_read, NULL, vcdev);
435 
436     if (vfio_set_irq_signaling(vdev, irq, 0,
437                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
438         qemu_set_fd_handler(fd, NULL, NULL, vcdev);
439         event_notifier_cleanup(notifier);
440     }
441 
442 out_free_info:
443     g_free(irq_info);
444 }
445 
446 static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
447                                              unsigned int irq)
448 {
449     Error *err = NULL;
450     EventNotifier *notifier;
451 
452     switch (irq) {
453     case VFIO_CCW_IO_IRQ_INDEX:
454         notifier = &vcdev->io_notifier;
455         break;
456     case VFIO_CCW_CRW_IRQ_INDEX:
457         notifier = &vcdev->crw_notifier;
458         break;
459     case VFIO_CCW_REQ_IRQ_INDEX:
460         notifier = &vcdev->req_notifier;
461         break;
462     default:
463         error_report("vfio: Unsupported device irq(%d)", irq);
464         return;
465     }
466 
467     if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
468                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
469         warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
470     }
471 
472     qemu_set_fd_handler(event_notifier_get_fd(notifier),
473                         NULL, NULL, vcdev);
474     event_notifier_cleanup(notifier);
475 }
476 
477 static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
478 {
479     VFIODevice *vdev = &vcdev->vdev;
480     struct vfio_region_info *info;
481     int ret;
482 
483     /* Sanity check device */
484     if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
485         error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
486         return;
487     }
488 
489     /*
490      * We always expect at least the I/O region to be present. We also
491      * may have a variable number of regions governed by capabilities.
492      */
493     if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
494         error_setg(errp, "vfio: too few regions (%u), expected at least %u",
495                    vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);
496         return;
497     }
498 
499     ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
500     if (ret) {
501         error_setg_errno(errp, -ret, "vfio: Error getting config info");
502         return;
503     }
504 
505     vcdev->io_region_size = info->size;
506     if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
507         error_setg(errp, "vfio: Unexpected size of the I/O region");
508         goto out_err;
509     }
510 
511     vcdev->io_region_offset = info->offset;
512     vcdev->io_region = g_malloc0(info->size);
513     g_free(info);
514 
515     /* check for the optional async command region */
516     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
517                                    VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info);
518     if (!ret) {
519         vcdev->async_cmd_region_size = info->size;
520         if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) {
521             error_setg(errp, "vfio: Unexpected size of the async cmd region");
522             goto out_err;
523         }
524         vcdev->async_cmd_region_offset = info->offset;
525         vcdev->async_cmd_region = g_malloc0(info->size);
526         g_free(info);
527     }
528 
529     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
530                                    VFIO_REGION_SUBTYPE_CCW_SCHIB, &info);
531     if (!ret) {
532         vcdev->schib_region_size = info->size;
533         if (sizeof(*vcdev->schib_region) != vcdev->schib_region_size) {
534             error_setg(errp, "vfio: Unexpected size of the schib region");
535             goto out_err;
536         }
537         vcdev->schib_region_offset = info->offset;
538         vcdev->schib_region = g_malloc(info->size);
539         g_free(info);
540     }
541 
542     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
543                                    VFIO_REGION_SUBTYPE_CCW_CRW, &info);
544 
545     if (!ret) {
546         vcdev->crw_region_size = info->size;
547         if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) {
548             error_setg(errp, "vfio: Unexpected size of the CRW region");
549             goto out_err;
550         }
551         vcdev->crw_region_offset = info->offset;
552         vcdev->crw_region = g_malloc(info->size);
553         g_free(info);
554     }
555 
556     return;
557 
558 out_err:
559     g_free(vcdev->crw_region);
560     g_free(vcdev->schib_region);
561     g_free(vcdev->async_cmd_region);
562     g_free(vcdev->io_region);
563     g_free(info);
564     return;
565 }
566 
567 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
568 {
569     g_free(vcdev->crw_region);
570     g_free(vcdev->schib_region);
571     g_free(vcdev->async_cmd_region);
572     g_free(vcdev->io_region);
573 }
574 
575 static void vfio_ccw_put_device(VFIOCCWDevice *vcdev)
576 {
577     g_free(vcdev->vdev.name);
578     vfio_put_base_device(&vcdev->vdev);
579 }
580 
581 static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
582                                 Error **errp)
583 {
584     S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
585     char *name = g_strdup_printf("%x.%x.%04x", cdev->hostid.cssid,
586                                  cdev->hostid.ssid,
587                                  cdev->hostid.devid);
588     VFIODevice *vbasedev;
589 
590     QLIST_FOREACH(vbasedev, &group->device_list, next) {
591         if (strcmp(vbasedev->name, name) == 0) {
592             error_setg(errp, "vfio: subchannel %s has already been attached",
593                        name);
594             goto out_err;
595         }
596     }
597 
598     /*
599      * All vfio-ccw devices are believed to operate in a way compatible with
600      * discarding of memory in RAM blocks, ie. pages pinned in the host are
601      * in the current working set of the guest driver and therefore never
602      * overlap e.g., with pages available to the guest balloon driver.  This
603      * needs to be set before vfio_get_device() for vfio common to handle
604      * ram_block_discard_disable().
605      */
606     vcdev->vdev.ram_block_discard_allowed = true;
607 
608     if (vfio_get_device(group, cdev->mdevid, &vcdev->vdev, errp)) {
609         goto out_err;
610     }
611 
612     vcdev->vdev.ops = &vfio_ccw_ops;
613     vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
614     vcdev->vdev.name = name;
615     vcdev->vdev.dev = DEVICE(vcdev);
616 
617     return;
618 
619 out_err:
620     g_free(name);
621 }
622 
623 static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
624 {
625     char *tmp, group_path[PATH_MAX];
626     ssize_t len;
627     int groupid;
628 
629     tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group",
630                           cdev->hostid.cssid, cdev->hostid.ssid,
631                           cdev->hostid.devid, cdev->mdevid);
632     len = readlink(tmp, group_path, sizeof(group_path));
633     g_free(tmp);
634 
635     if (len <= 0 || len >= sizeof(group_path)) {
636         error_setg(errp, "vfio: no iommu_group found");
637         return NULL;
638     }
639 
640     group_path[len] = 0;
641 
642     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
643         error_setg(errp, "vfio: failed to read %s", group_path);
644         return NULL;
645     }
646 
647     return vfio_get_group(groupid, &address_space_memory, errp);
648 }
649 
650 static void vfio_ccw_realize(DeviceState *dev, Error **errp)
651 {
652     VFIOGroup *group;
653     S390CCWDevice *cdev = S390_CCW_DEVICE(dev);
654     VFIOCCWDevice *vcdev = VFIO_CCW(cdev);
655     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
656     Error *err = NULL;
657 
658     /* Call the class init function for subchannel. */
659     if (cdc->realize) {
660         cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
661         if (err) {
662             goto out_err_propagate;
663         }
664     }
665 
666     group = vfio_ccw_get_group(cdev, &err);
667     if (!group) {
668         goto out_group_err;
669     }
670 
671     vfio_ccw_get_device(group, vcdev, &err);
672     if (err) {
673         goto out_device_err;
674     }
675 
676     vfio_ccw_get_region(vcdev, &err);
677     if (err) {
678         goto out_region_err;
679     }
680 
681     vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
682     if (err) {
683         goto out_io_notifier_err;
684     }
685 
686     if (vcdev->crw_region) {
687         vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
688         if (err) {
689             goto out_irq_notifier_err;
690         }
691     }
692 
693     vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
694     if (err) {
695         /*
696          * Report this error, but do not make it a failing condition.
697          * Lack of this IRQ in the host does not prevent normal operation.
698          */
699         error_report_err(err);
700     }
701 
702     return;
703 
704 out_irq_notifier_err:
705     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
706     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
707     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
708 out_io_notifier_err:
709     vfio_ccw_put_region(vcdev);
710 out_region_err:
711     vfio_ccw_put_device(vcdev);
712 out_device_err:
713     vfio_put_group(group);
714 out_group_err:
715     if (cdc->unrealize) {
716         cdc->unrealize(cdev);
717     }
718 out_err_propagate:
719     error_propagate(errp, err);
720 }
721 
722 static void vfio_ccw_unrealize(DeviceState *dev)
723 {
724     S390CCWDevice *cdev = S390_CCW_DEVICE(dev);
725     VFIOCCWDevice *vcdev = VFIO_CCW(cdev);
726     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
727     VFIOGroup *group = vcdev->vdev.group;
728 
729     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
730     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
731     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
732     vfio_ccw_put_region(vcdev);
733     vfio_ccw_put_device(vcdev);
734     vfio_put_group(group);
735 
736     if (cdc->unrealize) {
737         cdc->unrealize(cdev);
738     }
739 }
740 
741 static Property vfio_ccw_properties[] = {
742     DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
743     DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false),
744     DEFINE_PROP_END_OF_LIST(),
745 };
746 
747 static const VMStateDescription vfio_ccw_vmstate = {
748     .name = "vfio-ccw",
749     .unmigratable = 1,
750 };
751 
752 static void vfio_ccw_class_init(ObjectClass *klass, void *data)
753 {
754     DeviceClass *dc = DEVICE_CLASS(klass);
755     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
756 
757     device_class_set_props(dc, vfio_ccw_properties);
758     dc->vmsd = &vfio_ccw_vmstate;
759     dc->desc = "VFIO-based subchannel assignment";
760     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
761     dc->realize = vfio_ccw_realize;
762     dc->unrealize = vfio_ccw_unrealize;
763     dc->reset = vfio_ccw_reset;
764 
765     cdc->handle_request = vfio_ccw_handle_request;
766     cdc->handle_halt = vfio_ccw_handle_halt;
767     cdc->handle_clear = vfio_ccw_handle_clear;
768     cdc->handle_store = vfio_ccw_handle_store;
769 }
770 
771 static const TypeInfo vfio_ccw_info = {
772     .name = TYPE_VFIO_CCW,
773     .parent = TYPE_S390_CCW,
774     .instance_size = sizeof(VFIOCCWDevice),
775     .class_init = vfio_ccw_class_init,
776 };
777 
778 static void register_vfio_ccw_type(void)
779 {
780     type_register_static(&vfio_ccw_info);
781 }
782 
783 type_init(register_vfio_ccw_type)
784