xref: /openbmc/qemu/hw/vfio/ccw.c (revision e9e51b71)
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/sysbus.h"
24 #include "hw/vfio/vfio.h"
25 #include "hw/vfio/vfio-common.h"
26 #include "hw/s390x/s390-ccw.h"
27 #include "hw/s390x/vfio-ccw.h"
28 #include "hw/qdev-properties.h"
29 #include "hw/s390x/ccw-device.h"
30 #include "exec/address-spaces.h"
31 #include "qemu/error-report.h"
32 #include "qemu/main-loop.h"
33 #include "qemu/module.h"
34 
35 struct VFIOCCWDevice {
36     S390CCWDevice cdev;
37     VFIODevice vdev;
38     uint64_t io_region_size;
39     uint64_t io_region_offset;
40     struct ccw_io_region *io_region;
41     uint64_t async_cmd_region_size;
42     uint64_t async_cmd_region_offset;
43     struct ccw_cmd_region *async_cmd_region;
44     uint64_t schib_region_size;
45     uint64_t schib_region_offset;
46     struct ccw_schib_region *schib_region;
47     uint64_t crw_region_size;
48     uint64_t crw_region_offset;
49     struct ccw_crw_region *crw_region;
50     EventNotifier io_notifier;
51     EventNotifier crw_notifier;
52     EventNotifier req_notifier;
53     bool force_orb_pfch;
54     bool warned_orb_pfch;
55 };
56 
57 static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch,
58                                   const char *msg)
59 {
60     warn_report_once_cond(&vcdev->warned_orb_pfch,
61                           "vfio-ccw (devno %x.%x.%04x): %s",
62                           sch->cssid, sch->ssid, sch->devno, msg);
63 }
64 
65 static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
66 {
67     vdev->needs_reset = false;
68 }
69 
70 /*
71  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
72  * vfio_ccw device now.
73  */
74 struct VFIODeviceOps vfio_ccw_ops = {
75     .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
76 };
77 
78 static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
79 {
80     S390CCWDevice *cdev = sch->driver_data;
81     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
82     struct ccw_io_region *region = vcdev->io_region;
83     int ret;
84 
85     if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) {
86         sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH;
87         warn_once_pfch(vcdev, sch, "PFCH flag forced");
88     }
89 
90     QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
91     QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
92     QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
93 
94     memset(region, 0, sizeof(*region));
95 
96     memcpy(region->orb_area, &sch->orb, sizeof(ORB));
97     memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
98 
99 again:
100     ret = pwrite(vcdev->vdev.fd, region,
101                  vcdev->io_region_size, vcdev->io_region_offset);
102     if (ret != vcdev->io_region_size) {
103         if (errno == EAGAIN) {
104             goto again;
105         }
106         error_report("vfio-ccw: write I/O region failed with errno=%d", errno);
107         ret = -errno;
108     } else {
109         ret = region->ret_code;
110     }
111     switch (ret) {
112     case 0:
113         return IOINST_CC_EXPECTED;
114     case -EBUSY:
115         return IOINST_CC_BUSY;
116     case -ENODEV:
117     case -EACCES:
118         return IOINST_CC_NOT_OPERATIONAL;
119     case -EFAULT:
120     default:
121         sch_gen_unit_exception(sch);
122         css_inject_io_interrupt(sch);
123         return IOINST_CC_EXPECTED;
124     }
125 }
126 
127 static IOInstEnding vfio_ccw_handle_store(SubchDev *sch)
128 {
129     S390CCWDevice *cdev = sch->driver_data;
130     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
131     SCHIB *schib = &sch->curr_status;
132     struct ccw_schib_region *region = vcdev->schib_region;
133     SCHIB *s;
134     int ret;
135 
136     /* schib region not available so nothing else to do */
137     if (!region) {
138         return IOINST_CC_EXPECTED;
139     }
140 
141     memset(region, 0, sizeof(*region));
142     ret = pread(vcdev->vdev.fd, region, vcdev->schib_region_size,
143                 vcdev->schib_region_offset);
144 
145     if (ret == -1) {
146         /*
147          * Device is probably damaged, but store subchannel does not
148          * have a nonzero cc defined for this scenario.  Log an error,
149          * and presume things are otherwise fine.
150          */
151         error_report("vfio-ccw: store region read failed with errno=%d", errno);
152         return IOINST_CC_EXPECTED;
153     }
154 
155     /*
156      * Selectively copy path-related bits of the SCHIB,
157      * rather than copying the entire struct.
158      */
159     s = (SCHIB *)region->schib_area;
160     schib->pmcw.pnom = s->pmcw.pnom;
161     schib->pmcw.lpum = s->pmcw.lpum;
162     schib->pmcw.pam = s->pmcw.pam;
163     schib->pmcw.pom = s->pmcw.pom;
164 
165     if (s->scsw.flags & SCSW_FLAGS_MASK_PNO) {
166         schib->scsw.flags |= SCSW_FLAGS_MASK_PNO;
167     }
168 
169     return IOINST_CC_EXPECTED;
170 }
171 
172 static int vfio_ccw_handle_clear(SubchDev *sch)
173 {
174     S390CCWDevice *cdev = sch->driver_data;
175     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
176     struct ccw_cmd_region *region = vcdev->async_cmd_region;
177     int ret;
178 
179     if (!vcdev->async_cmd_region) {
180         /* Async command region not available, fall back to emulation */
181         return -ENOSYS;
182     }
183 
184     memset(region, 0, sizeof(*region));
185     region->command = VFIO_CCW_ASYNC_CMD_CSCH;
186 
187 again:
188     ret = pwrite(vcdev->vdev.fd, region,
189                  vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
190     if (ret != vcdev->async_cmd_region_size) {
191         if (errno == EAGAIN) {
192             goto again;
193         }
194         error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
195         ret = -errno;
196     } else {
197         ret = region->ret_code;
198     }
199     switch (ret) {
200     case 0:
201     case -ENODEV:
202     case -EACCES:
203         return 0;
204     case -EFAULT:
205     default:
206         sch_gen_unit_exception(sch);
207         css_inject_io_interrupt(sch);
208         return 0;
209     }
210 }
211 
212 static int vfio_ccw_handle_halt(SubchDev *sch)
213 {
214     S390CCWDevice *cdev = sch->driver_data;
215     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
216     struct ccw_cmd_region *region = vcdev->async_cmd_region;
217     int ret;
218 
219     if (!vcdev->async_cmd_region) {
220         /* Async command region not available, fall back to emulation */
221         return -ENOSYS;
222     }
223 
224     memset(region, 0, sizeof(*region));
225     region->command = VFIO_CCW_ASYNC_CMD_HSCH;
226 
227 again:
228     ret = pwrite(vcdev->vdev.fd, region,
229                  vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
230     if (ret != vcdev->async_cmd_region_size) {
231         if (errno == EAGAIN) {
232             goto again;
233         }
234         error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
235         ret = -errno;
236     } else {
237         ret = region->ret_code;
238     }
239     switch (ret) {
240     case 0:
241     case -EBUSY:
242     case -ENODEV:
243     case -EACCES:
244         return 0;
245     case -EFAULT:
246     default:
247         sch_gen_unit_exception(sch);
248         css_inject_io_interrupt(sch);
249         return 0;
250     }
251 }
252 
253 static void vfio_ccw_reset(DeviceState *dev)
254 {
255     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
256     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
257     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
258 
259     ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
260 }
261 
262 static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
263 {
264     struct ccw_crw_region *region = vcdev->crw_region;
265     CRW crw;
266     int size;
267 
268     /* Keep reading CRWs as long as data is returned */
269     do {
270         memset(region, 0, sizeof(*region));
271         size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size,
272                      vcdev->crw_region_offset);
273 
274         if (size == -1) {
275             error_report("vfio-ccw: Read crw region failed with errno=%d",
276                          errno);
277             break;
278         }
279 
280         if (region->crw == 0) {
281             /* No more CRWs to queue */
282             break;
283         }
284 
285         memcpy(&crw, &region->crw, sizeof(CRW));
286 
287         css_crw_add_to_queue(crw);
288     } while (1);
289 }
290 
291 static void vfio_ccw_req_notifier_handler(void *opaque)
292 {
293     VFIOCCWDevice *vcdev = opaque;
294     Error *err = NULL;
295 
296     if (!event_notifier_test_and_clear(&vcdev->req_notifier)) {
297         return;
298     }
299 
300     qdev_unplug(DEVICE(vcdev), &err);
301     if (err) {
302         warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
303     }
304 }
305 
306 static void vfio_ccw_crw_notifier_handler(void *opaque)
307 {
308     VFIOCCWDevice *vcdev = opaque;
309 
310     while (event_notifier_test_and_clear(&vcdev->crw_notifier)) {
311         vfio_ccw_crw_read(vcdev);
312     }
313 }
314 
315 static void vfio_ccw_io_notifier_handler(void *opaque)
316 {
317     VFIOCCWDevice *vcdev = opaque;
318     struct ccw_io_region *region = vcdev->io_region;
319     S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
320     CcwDevice *ccw_dev = CCW_DEVICE(cdev);
321     SubchDev *sch = ccw_dev->sch;
322     SCHIB *schib = &sch->curr_status;
323     SCSW s;
324     IRB irb;
325     int size;
326 
327     if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
328         return;
329     }
330 
331     size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
332                  vcdev->io_region_offset);
333     if (size == -1) {
334         switch (errno) {
335         case ENODEV:
336             /* Generate a deferred cc 3 condition. */
337             schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
338             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
339             schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
340             goto read_err;
341         case EFAULT:
342             /* Memory problem, generate channel data check. */
343             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
344             schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK;
345             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
346             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
347                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
348             goto read_err;
349         default:
350             /* Error, generate channel program check. */
351             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
352             schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
353             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
354             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
355                        SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
356             goto read_err;
357         }
358     } else if (size != vcdev->io_region_size) {
359         /* Information transfer error, generate channel-control check. */
360         schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
361         schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK;
362         schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
363         schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
364                    SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
365         goto read_err;
366     }
367 
368     memcpy(&irb, region->irb_area, sizeof(IRB));
369 
370     /* Update control block via irb. */
371     s = schib->scsw;
372     copy_scsw_to_guest(&s, &irb.scsw);
373     schib->scsw = s;
374 
375     /* If a uint check is pending, copy sense data. */
376     if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
377         (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
378         memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
379     }
380 
381 read_err:
382     css_inject_io_interrupt(sch);
383 }
384 
385 static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
386                                            unsigned int irq,
387                                            Error **errp)
388 {
389     VFIODevice *vdev = &vcdev->vdev;
390     struct vfio_irq_info *irq_info;
391     size_t argsz;
392     int fd;
393     EventNotifier *notifier;
394     IOHandler *fd_read;
395 
396     switch (irq) {
397     case VFIO_CCW_IO_IRQ_INDEX:
398         notifier = &vcdev->io_notifier;
399         fd_read = vfio_ccw_io_notifier_handler;
400         break;
401     case VFIO_CCW_CRW_IRQ_INDEX:
402         notifier = &vcdev->crw_notifier;
403         fd_read = vfio_ccw_crw_notifier_handler;
404         break;
405     case VFIO_CCW_REQ_IRQ_INDEX:
406         notifier = &vcdev->req_notifier;
407         fd_read = vfio_ccw_req_notifier_handler;
408         break;
409     default:
410         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
411         return;
412     }
413 
414     if (vdev->num_irqs < irq + 1) {
415         error_setg(errp, "vfio: unexpected number of irqs %u",
416                    vdev->num_irqs);
417         return;
418     }
419 
420     argsz = sizeof(*irq_info);
421     irq_info = g_malloc0(argsz);
422     irq_info->index = irq;
423     irq_info->argsz = argsz;
424     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
425               irq_info) < 0 || irq_info->count < 1) {
426         error_setg_errno(errp, errno, "vfio: Error getting irq info");
427         goto out_free_info;
428     }
429 
430     if (event_notifier_init(notifier, 0)) {
431         error_setg_errno(errp, errno,
432                          "vfio: Unable to init event notifier for irq (%d)",
433                          irq);
434         goto out_free_info;
435     }
436 
437     fd = event_notifier_get_fd(notifier);
438     qemu_set_fd_handler(fd, fd_read, NULL, vcdev);
439 
440     if (vfio_set_irq_signaling(vdev, irq, 0,
441                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
442         qemu_set_fd_handler(fd, NULL, NULL, vcdev);
443         event_notifier_cleanup(notifier);
444     }
445 
446 out_free_info:
447     g_free(irq_info);
448 }
449 
450 static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
451                                              unsigned int irq)
452 {
453     Error *err = NULL;
454     EventNotifier *notifier;
455 
456     switch (irq) {
457     case VFIO_CCW_IO_IRQ_INDEX:
458         notifier = &vcdev->io_notifier;
459         break;
460     case VFIO_CCW_CRW_IRQ_INDEX:
461         notifier = &vcdev->crw_notifier;
462         break;
463     case VFIO_CCW_REQ_IRQ_INDEX:
464         notifier = &vcdev->req_notifier;
465         break;
466     default:
467         error_report("vfio: Unsupported device irq(%d)", irq);
468         return;
469     }
470 
471     if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
472                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
473         error_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
474     }
475 
476     qemu_set_fd_handler(event_notifier_get_fd(notifier),
477                         NULL, NULL, vcdev);
478     event_notifier_cleanup(notifier);
479 }
480 
481 static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
482 {
483     VFIODevice *vdev = &vcdev->vdev;
484     struct vfio_region_info *info;
485     int ret;
486 
487     /* Sanity check device */
488     if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
489         error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
490         return;
491     }
492 
493     /*
494      * We always expect at least the I/O region to be present. We also
495      * may have a variable number of regions governed by capabilities.
496      */
497     if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
498         error_setg(errp, "vfio: too few regions (%u), expected at least %u",
499                    vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);
500         return;
501     }
502 
503     ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
504     if (ret) {
505         error_setg_errno(errp, -ret, "vfio: Error getting config info");
506         return;
507     }
508 
509     vcdev->io_region_size = info->size;
510     if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
511         error_setg(errp, "vfio: Unexpected size of the I/O region");
512         goto out_err;
513     }
514 
515     vcdev->io_region_offset = info->offset;
516     vcdev->io_region = g_malloc0(info->size);
517     g_free(info);
518 
519     /* check for the optional async command region */
520     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
521                                    VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info);
522     if (!ret) {
523         vcdev->async_cmd_region_size = info->size;
524         if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) {
525             error_setg(errp, "vfio: Unexpected size of the async cmd region");
526             goto out_err;
527         }
528         vcdev->async_cmd_region_offset = info->offset;
529         vcdev->async_cmd_region = g_malloc0(info->size);
530         g_free(info);
531     }
532 
533     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
534                                    VFIO_REGION_SUBTYPE_CCW_SCHIB, &info);
535     if (!ret) {
536         vcdev->schib_region_size = info->size;
537         if (sizeof(*vcdev->schib_region) != vcdev->schib_region_size) {
538             error_setg(errp, "vfio: Unexpected size of the schib region");
539             goto out_err;
540         }
541         vcdev->schib_region_offset = info->offset;
542         vcdev->schib_region = g_malloc(info->size);
543         g_free(info);
544     }
545 
546     ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
547                                    VFIO_REGION_SUBTYPE_CCW_CRW, &info);
548 
549     if (!ret) {
550         vcdev->crw_region_size = info->size;
551         if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) {
552             error_setg(errp, "vfio: Unexpected size of the CRW region");
553             goto out_err;
554         }
555         vcdev->crw_region_offset = info->offset;
556         vcdev->crw_region = g_malloc(info->size);
557         g_free(info);
558     }
559 
560     return;
561 
562 out_err:
563     g_free(vcdev->crw_region);
564     g_free(vcdev->schib_region);
565     g_free(vcdev->async_cmd_region);
566     g_free(vcdev->io_region);
567     g_free(info);
568     return;
569 }
570 
571 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
572 {
573     g_free(vcdev->crw_region);
574     g_free(vcdev->schib_region);
575     g_free(vcdev->async_cmd_region);
576     g_free(vcdev->io_region);
577 }
578 
579 static void vfio_ccw_put_device(VFIOCCWDevice *vcdev)
580 {
581     g_free(vcdev->vdev.name);
582     vfio_put_base_device(&vcdev->vdev);
583 }
584 
585 static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
586                                 Error **errp)
587 {
588     char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid,
589                                  vcdev->cdev.hostid.ssid,
590                                  vcdev->cdev.hostid.devid);
591     VFIODevice *vbasedev;
592 
593     QLIST_FOREACH(vbasedev, &group->device_list, next) {
594         if (strcmp(vbasedev->name, name) == 0) {
595             error_setg(errp, "vfio: subchannel %s has already been attached",
596                        name);
597             goto out_err;
598         }
599     }
600 
601     /*
602      * All vfio-ccw devices are believed to operate in a way compatible with
603      * discarding of memory in RAM blocks, ie. pages pinned in the host are
604      * in the current working set of the guest driver and therefore never
605      * overlap e.g., with pages available to the guest balloon driver.  This
606      * needs to be set before vfio_get_device() for vfio common to handle
607      * ram_block_discard_disable().
608      */
609     vcdev->vdev.ram_block_discard_allowed = true;
610 
611     if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
612         goto out_err;
613     }
614 
615     vcdev->vdev.ops = &vfio_ccw_ops;
616     vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
617     vcdev->vdev.name = name;
618     vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj;
619 
620     return;
621 
622 out_err:
623     g_free(name);
624 }
625 
626 static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
627 {
628     char *tmp, group_path[PATH_MAX];
629     ssize_t len;
630     int groupid;
631 
632     tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group",
633                           cdev->hostid.cssid, cdev->hostid.ssid,
634                           cdev->hostid.devid, cdev->mdevid);
635     len = readlink(tmp, group_path, sizeof(group_path));
636     g_free(tmp);
637 
638     if (len <= 0 || len >= sizeof(group_path)) {
639         error_setg(errp, "vfio: no iommu_group found");
640         return NULL;
641     }
642 
643     group_path[len] = 0;
644 
645     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
646         error_setg(errp, "vfio: failed to read %s", group_path);
647         return NULL;
648     }
649 
650     return vfio_get_group(groupid, &address_space_memory, errp);
651 }
652 
653 static void vfio_ccw_realize(DeviceState *dev, Error **errp)
654 {
655     VFIOGroup *group;
656     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
657     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
658     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
659     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
660     Error *err = NULL;
661 
662     /* Call the class init function for subchannel. */
663     if (cdc->realize) {
664         cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
665         if (err) {
666             goto out_err_propagate;
667         }
668     }
669 
670     group = vfio_ccw_get_group(cdev, &err);
671     if (!group) {
672         goto out_group_err;
673     }
674 
675     vfio_ccw_get_device(group, vcdev, &err);
676     if (err) {
677         goto out_device_err;
678     }
679 
680     vfio_ccw_get_region(vcdev, &err);
681     if (err) {
682         goto out_region_err;
683     }
684 
685     vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
686     if (err) {
687         goto out_io_notifier_err;
688     }
689 
690     if (vcdev->crw_region) {
691         vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
692         if (err) {
693             goto out_crw_notifier_err;
694         }
695     }
696 
697     vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
698     if (err) {
699         goto out_req_notifier_err;
700     }
701 
702     return;
703 
704 out_req_notifier_err:
705     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
706 out_crw_notifier_err:
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     CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
725     S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
726     VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
727     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
728     VFIOGroup *group = vcdev->vdev.group;
729 
730     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
731     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
732     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
733     vfio_ccw_put_region(vcdev);
734     vfio_ccw_put_device(vcdev);
735     vfio_put_group(group);
736 
737     if (cdc->unrealize) {
738         cdc->unrealize(cdev);
739     }
740 }
741 
742 static Property vfio_ccw_properties[] = {
743     DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
744     DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false),
745     DEFINE_PROP_END_OF_LIST(),
746 };
747 
748 static const VMStateDescription vfio_ccw_vmstate = {
749     .name = "vfio-ccw",
750     .unmigratable = 1,
751 };
752 
753 static void vfio_ccw_class_init(ObjectClass *klass, void *data)
754 {
755     DeviceClass *dc = DEVICE_CLASS(klass);
756     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
757 
758     device_class_set_props(dc, vfio_ccw_properties);
759     dc->vmsd = &vfio_ccw_vmstate;
760     dc->desc = "VFIO-based subchannel assignment";
761     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
762     dc->realize = vfio_ccw_realize;
763     dc->unrealize = vfio_ccw_unrealize;
764     dc->reset = vfio_ccw_reset;
765 
766     cdc->handle_request = vfio_ccw_handle_request;
767     cdc->handle_halt = vfio_ccw_handle_halt;
768     cdc->handle_clear = vfio_ccw_handle_clear;
769     cdc->handle_store = vfio_ccw_handle_store;
770 }
771 
772 static const TypeInfo vfio_ccw_info = {
773     .name = TYPE_VFIO_CCW,
774     .parent = TYPE_S390_CCW,
775     .instance_size = sizeof(VFIOCCWDevice),
776     .class_init = vfio_ccw_class_init,
777 };
778 
779 static void register_vfio_ccw_type(void)
780 {
781     type_register_static(&vfio_ccw_info);
782 }
783 
784 type_init(register_vfio_ccw_type)
785