xref: /openbmc/qemu/hw/s390x/css.c (revision 679cb8e1)
1 /*
2  * Channel subsystem base support.
3  *
4  * Copyright 2012 IBM Corp.
5  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or (at
8  * your option) any later version. See the COPYING file in the top-level
9  * directory.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "qapi/visitor.h"
15 #include "hw/qdev.h"
16 #include "qemu/bitops.h"
17 #include "qemu/error-report.h"
18 #include "exec/address-spaces.h"
19 #include "cpu.h"
20 #include "hw/s390x/ioinst.h"
21 #include "hw/s390x/css.h"
22 #include "trace.h"
23 #include "hw/s390x/s390_flic.h"
24 #include "hw/s390x/s390-virtio-ccw.h"
25 
26 typedef struct CrwContainer {
27     CRW crw;
28     QTAILQ_ENTRY(CrwContainer) sibling;
29 } CrwContainer;
30 
31 static const VMStateDescription vmstate_crw = {
32     .name = "s390_crw",
33     .version_id = 1,
34     .minimum_version_id = 1,
35     .fields = (VMStateField[]) {
36         VMSTATE_UINT16(flags, CRW),
37         VMSTATE_UINT16(rsid, CRW),
38         VMSTATE_END_OF_LIST()
39     },
40 };
41 
42 static const VMStateDescription vmstate_crw_container = {
43     .name = "s390_crw_container",
44     .version_id = 1,
45     .minimum_version_id = 1,
46     .fields = (VMStateField[]) {
47         VMSTATE_STRUCT(crw, CrwContainer, 0, vmstate_crw, CRW),
48         VMSTATE_END_OF_LIST()
49     },
50 };
51 
52 typedef struct ChpInfo {
53     uint8_t in_use;
54     uint8_t type;
55     uint8_t is_virtual;
56 } ChpInfo;
57 
58 static const VMStateDescription vmstate_chp_info = {
59     .name = "s390_chp_info",
60     .version_id = 1,
61     .minimum_version_id = 1,
62     .fields = (VMStateField[]) {
63         VMSTATE_UINT8(in_use, ChpInfo),
64         VMSTATE_UINT8(type, ChpInfo),
65         VMSTATE_UINT8(is_virtual, ChpInfo),
66         VMSTATE_END_OF_LIST()
67     }
68 };
69 
70 typedef struct SubchSet {
71     SubchDev *sch[MAX_SCHID + 1];
72     unsigned long schids_used[BITS_TO_LONGS(MAX_SCHID + 1)];
73     unsigned long devnos_used[BITS_TO_LONGS(MAX_SCHID + 1)];
74 } SubchSet;
75 
76 static const VMStateDescription vmstate_scsw = {
77     .name = "s390_scsw",
78     .version_id = 1,
79     .minimum_version_id = 1,
80     .fields = (VMStateField[]) {
81         VMSTATE_UINT16(flags, SCSW),
82         VMSTATE_UINT16(ctrl, SCSW),
83         VMSTATE_UINT32(cpa, SCSW),
84         VMSTATE_UINT8(dstat, SCSW),
85         VMSTATE_UINT8(cstat, SCSW),
86         VMSTATE_UINT16(count, SCSW),
87         VMSTATE_END_OF_LIST()
88     }
89 };
90 
91 static const VMStateDescription vmstate_pmcw = {
92     .name = "s390_pmcw",
93     .version_id = 1,
94     .minimum_version_id = 1,
95     .fields = (VMStateField[]) {
96         VMSTATE_UINT32(intparm, PMCW),
97         VMSTATE_UINT16(flags, PMCW),
98         VMSTATE_UINT16(devno, PMCW),
99         VMSTATE_UINT8(lpm, PMCW),
100         VMSTATE_UINT8(pnom, PMCW),
101         VMSTATE_UINT8(lpum, PMCW),
102         VMSTATE_UINT8(pim, PMCW),
103         VMSTATE_UINT16(mbi, PMCW),
104         VMSTATE_UINT8(pom, PMCW),
105         VMSTATE_UINT8(pam, PMCW),
106         VMSTATE_UINT8_ARRAY(chpid, PMCW, 8),
107         VMSTATE_UINT32(chars, PMCW),
108         VMSTATE_END_OF_LIST()
109     }
110 };
111 
112 static const VMStateDescription vmstate_schib = {
113     .name = "s390_schib",
114     .version_id = 1,
115     .minimum_version_id = 1,
116     .fields = (VMStateField[]) {
117         VMSTATE_STRUCT(pmcw, SCHIB, 0, vmstate_pmcw, PMCW),
118         VMSTATE_STRUCT(scsw, SCHIB, 0, vmstate_scsw, SCSW),
119         VMSTATE_UINT64(mba, SCHIB),
120         VMSTATE_UINT8_ARRAY(mda, SCHIB, 4),
121         VMSTATE_END_OF_LIST()
122     }
123 };
124 
125 
126 static const VMStateDescription vmstate_ccw1 = {
127     .name = "s390_ccw1",
128     .version_id = 1,
129     .minimum_version_id = 1,
130     .fields = (VMStateField[]) {
131         VMSTATE_UINT8(cmd_code, CCW1),
132         VMSTATE_UINT8(flags, CCW1),
133         VMSTATE_UINT16(count, CCW1),
134         VMSTATE_UINT32(cda, CCW1),
135         VMSTATE_END_OF_LIST()
136     }
137 };
138 
139 static const VMStateDescription vmstate_ciw = {
140     .name = "s390_ciw",
141     .version_id = 1,
142     .minimum_version_id = 1,
143     .fields = (VMStateField[]) {
144         VMSTATE_UINT8(type, CIW),
145         VMSTATE_UINT8(command, CIW),
146         VMSTATE_UINT16(count, CIW),
147         VMSTATE_END_OF_LIST()
148     }
149 };
150 
151 static const VMStateDescription vmstate_sense_id = {
152     .name = "s390_sense_id",
153     .version_id = 1,
154     .minimum_version_id = 1,
155     .fields = (VMStateField[]) {
156         VMSTATE_UINT8(reserved, SenseId),
157         VMSTATE_UINT16(cu_type, SenseId),
158         VMSTATE_UINT8(cu_model, SenseId),
159         VMSTATE_UINT16(dev_type, SenseId),
160         VMSTATE_UINT8(dev_model, SenseId),
161         VMSTATE_UINT8(unused, SenseId),
162         VMSTATE_STRUCT_ARRAY(ciw, SenseId, MAX_CIWS, 0, vmstate_ciw, CIW),
163         VMSTATE_END_OF_LIST()
164     }
165 };
166 
167 static const VMStateDescription vmstate_orb = {
168     .name = "s390_orb",
169     .version_id = 1,
170     .minimum_version_id = 1,
171     .fields = (VMStateField[]) {
172         VMSTATE_UINT32(intparm, ORB),
173         VMSTATE_UINT16(ctrl0, ORB),
174         VMSTATE_UINT8(lpm, ORB),
175         VMSTATE_UINT8(ctrl1, ORB),
176         VMSTATE_UINT32(cpa, ORB),
177         VMSTATE_END_OF_LIST()
178     }
179 };
180 
181 static bool vmstate_schdev_orb_needed(void *opaque)
182 {
183     return css_migration_enabled();
184 }
185 
186 static const VMStateDescription vmstate_schdev_orb = {
187     .name = "s390_subch_dev/orb",
188     .version_id = 1,
189     .minimum_version_id = 1,
190     .needed = vmstate_schdev_orb_needed,
191     .fields = (VMStateField[]) {
192         VMSTATE_STRUCT(orb, SubchDev, 1, vmstate_orb, ORB),
193         VMSTATE_END_OF_LIST()
194     }
195 };
196 
197 static int subch_dev_post_load(void *opaque, int version_id);
198 static int subch_dev_pre_save(void *opaque);
199 
200 const char err_hint_devno[] = "Devno mismatch, tried to load wrong section!"
201     " Likely reason: some sequences of plug and unplug  can break"
202     " migration for machine versions prior to  2.7 (known design flaw).";
203 
204 const VMStateDescription vmstate_subch_dev = {
205     .name = "s390_subch_dev",
206     .version_id = 1,
207     .minimum_version_id = 1,
208     .post_load = subch_dev_post_load,
209     .pre_save = subch_dev_pre_save,
210     .fields = (VMStateField[]) {
211         VMSTATE_UINT8_EQUAL(cssid, SubchDev, "Bug!"),
212         VMSTATE_UINT8_EQUAL(ssid, SubchDev, "Bug!"),
213         VMSTATE_UINT16(migrated_schid, SubchDev),
214         VMSTATE_UINT16_EQUAL(devno, SubchDev, err_hint_devno),
215         VMSTATE_BOOL(thinint_active, SubchDev),
216         VMSTATE_STRUCT(curr_status, SubchDev, 0, vmstate_schib, SCHIB),
217         VMSTATE_UINT8_ARRAY(sense_data, SubchDev, 32),
218         VMSTATE_UINT64(channel_prog, SubchDev),
219         VMSTATE_STRUCT(last_cmd, SubchDev, 0, vmstate_ccw1, CCW1),
220         VMSTATE_BOOL(last_cmd_valid, SubchDev),
221         VMSTATE_STRUCT(id, SubchDev, 0, vmstate_sense_id, SenseId),
222         VMSTATE_BOOL(ccw_fmt_1, SubchDev),
223         VMSTATE_UINT8(ccw_no_data_cnt, SubchDev),
224         VMSTATE_END_OF_LIST()
225     },
226     .subsections = (const VMStateDescription * []) {
227         &vmstate_schdev_orb,
228         NULL
229     }
230 };
231 
232 typedef struct IndAddrPtrTmp {
233     IndAddr **parent;
234     uint64_t addr;
235     int32_t len;
236 } IndAddrPtrTmp;
237 
238 static int post_load_ind_addr(void *opaque, int version_id)
239 {
240     IndAddrPtrTmp *ptmp = opaque;
241     IndAddr **ind_addr = ptmp->parent;
242 
243     if (ptmp->len != 0) {
244         *ind_addr = get_indicator(ptmp->addr, ptmp->len);
245     } else {
246         *ind_addr = NULL;
247     }
248     return 0;
249 }
250 
251 static int pre_save_ind_addr(void *opaque)
252 {
253     IndAddrPtrTmp *ptmp = opaque;
254     IndAddr *ind_addr = *(ptmp->parent);
255 
256     if (ind_addr != NULL) {
257         ptmp->len = ind_addr->len;
258         ptmp->addr = ind_addr->addr;
259     } else {
260         ptmp->len = 0;
261         ptmp->addr = 0L;
262     }
263 
264     return 0;
265 }
266 
267 const VMStateDescription vmstate_ind_addr_tmp = {
268     .name = "s390_ind_addr_tmp",
269     .pre_save = pre_save_ind_addr,
270     .post_load = post_load_ind_addr,
271 
272     .fields = (VMStateField[]) {
273         VMSTATE_INT32(len, IndAddrPtrTmp),
274         VMSTATE_UINT64(addr, IndAddrPtrTmp),
275         VMSTATE_END_OF_LIST()
276     }
277 };
278 
279 const VMStateDescription vmstate_ind_addr = {
280     .name = "s390_ind_addr_tmp",
281     .fields = (VMStateField[]) {
282         VMSTATE_WITH_TMP(IndAddr*, IndAddrPtrTmp, vmstate_ind_addr_tmp),
283         VMSTATE_END_OF_LIST()
284     }
285 };
286 
287 typedef struct CssImage {
288     SubchSet *sch_set[MAX_SSID + 1];
289     ChpInfo chpids[MAX_CHPID + 1];
290 } CssImage;
291 
292 static const VMStateDescription vmstate_css_img = {
293     .name = "s390_css_img",
294     .version_id = 1,
295     .minimum_version_id = 1,
296     .fields = (VMStateField[]) {
297         /* Subchannel sets have no relevant state. */
298         VMSTATE_STRUCT_ARRAY(chpids, CssImage, MAX_CHPID + 1, 0,
299                              vmstate_chp_info, ChpInfo),
300         VMSTATE_END_OF_LIST()
301     }
302 
303 };
304 
305 typedef struct IoAdapter {
306     uint32_t id;
307     uint8_t type;
308     uint8_t isc;
309     uint8_t flags;
310 } IoAdapter;
311 
312 typedef struct ChannelSubSys {
313     QTAILQ_HEAD(, CrwContainer) pending_crws;
314     bool sei_pending;
315     bool do_crw_mchk;
316     bool crws_lost;
317     uint8_t max_cssid;
318     uint8_t max_ssid;
319     bool chnmon_active;
320     uint64_t chnmon_area;
321     CssImage *css[MAX_CSSID + 1];
322     uint8_t default_cssid;
323     /* don't migrate, see css_register_io_adapters */
324     IoAdapter *io_adapters[CSS_IO_ADAPTER_TYPE_NUMS][MAX_ISC + 1];
325     /* don't migrate, see get_indicator and IndAddrPtrTmp */
326     QTAILQ_HEAD(, IndAddr) indicator_addresses;
327 } ChannelSubSys;
328 
329 static const VMStateDescription vmstate_css = {
330     .name = "s390_css",
331     .version_id = 1,
332     .minimum_version_id = 1,
333     .fields = (VMStateField[]) {
334         VMSTATE_QTAILQ_V(pending_crws, ChannelSubSys, 1, vmstate_crw_container,
335                          CrwContainer, sibling),
336         VMSTATE_BOOL(sei_pending, ChannelSubSys),
337         VMSTATE_BOOL(do_crw_mchk, ChannelSubSys),
338         VMSTATE_BOOL(crws_lost, ChannelSubSys),
339         /* These were kind of migrated by virtio */
340         VMSTATE_UINT8(max_cssid, ChannelSubSys),
341         VMSTATE_UINT8(max_ssid, ChannelSubSys),
342         VMSTATE_BOOL(chnmon_active, ChannelSubSys),
343         VMSTATE_UINT64(chnmon_area, ChannelSubSys),
344         VMSTATE_ARRAY_OF_POINTER_TO_STRUCT(css, ChannelSubSys, MAX_CSSID + 1,
345                 0, vmstate_css_img, CssImage),
346         VMSTATE_UINT8(default_cssid, ChannelSubSys),
347         VMSTATE_END_OF_LIST()
348     }
349 };
350 
351 static ChannelSubSys channel_subsys = {
352     .pending_crws = QTAILQ_HEAD_INITIALIZER(channel_subsys.pending_crws),
353     .do_crw_mchk = true,
354     .sei_pending = false,
355     .do_crw_mchk = true,
356     .crws_lost = false,
357     .chnmon_active = false,
358     .indicator_addresses =
359         QTAILQ_HEAD_INITIALIZER(channel_subsys.indicator_addresses),
360 };
361 
362 static int subch_dev_pre_save(void *opaque)
363 {
364     SubchDev *s = opaque;
365 
366     /* Prepare remote_schid for save */
367     s->migrated_schid = s->schid;
368 
369     return 0;
370 }
371 
372 static int subch_dev_post_load(void *opaque, int version_id)
373 {
374 
375     SubchDev *s = opaque;
376 
377     /* Re-assign the subchannel to remote_schid if necessary */
378     if (s->migrated_schid != s->schid) {
379         if (css_find_subch(true, s->cssid, s->ssid, s->schid) == s) {
380             /*
381              * Cleanup the slot before moving to s->migrated_schid provided
382              * it still belongs to us, i.e. it was not changed by previous
383              * invocation of this function.
384              */
385             css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, NULL);
386         }
387         /* It's OK to re-assign without a prior de-assign. */
388         s->schid = s->migrated_schid;
389         css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, s);
390     }
391 
392     if (css_migration_enabled()) {
393         /* No compat voodoo to do ;) */
394         return 0;
395     }
396     /*
397      * Hack alert. If we don't migrate the channel subsystem status
398      * we still need to find out if the guest enabled mss/mcss-e.
399      * If the subchannel is enabled, it certainly was able to access it,
400      * so adjust the max_ssid/max_cssid values for relevant ssid/cssid
401      * values. This is not watertight, but better than nothing.
402      */
403     if (s->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA) {
404         if (s->ssid) {
405             channel_subsys.max_ssid = MAX_SSID;
406         }
407         if (s->cssid != channel_subsys.default_cssid) {
408             channel_subsys.max_cssid = MAX_CSSID;
409         }
410     }
411     return 0;
412 }
413 
414 void css_register_vmstate(void)
415 {
416     vmstate_register(NULL, 0, &vmstate_css, &channel_subsys);
417 }
418 
419 IndAddr *get_indicator(hwaddr ind_addr, int len)
420 {
421     IndAddr *indicator;
422 
423     QTAILQ_FOREACH(indicator, &channel_subsys.indicator_addresses, sibling) {
424         if (indicator->addr == ind_addr) {
425             indicator->refcnt++;
426             return indicator;
427         }
428     }
429     indicator = g_new0(IndAddr, 1);
430     indicator->addr = ind_addr;
431     indicator->len = len;
432     indicator->refcnt = 1;
433     QTAILQ_INSERT_TAIL(&channel_subsys.indicator_addresses,
434                        indicator, sibling);
435     return indicator;
436 }
437 
438 static int s390_io_adapter_map(AdapterInfo *adapter, uint64_t map_addr,
439                                bool do_map)
440 {
441     S390FLICState *fs = s390_get_flic();
442     S390FLICStateClass *fsc = s390_get_flic_class(fs);
443 
444     return fsc->io_adapter_map(fs, adapter->adapter_id, map_addr, do_map);
445 }
446 
447 void release_indicator(AdapterInfo *adapter, IndAddr *indicator)
448 {
449     assert(indicator->refcnt > 0);
450     indicator->refcnt--;
451     if (indicator->refcnt > 0) {
452         return;
453     }
454     QTAILQ_REMOVE(&channel_subsys.indicator_addresses, indicator, sibling);
455     if (indicator->map) {
456         s390_io_adapter_map(adapter, indicator->map, false);
457     }
458     g_free(indicator);
459 }
460 
461 int map_indicator(AdapterInfo *adapter, IndAddr *indicator)
462 {
463     int ret;
464 
465     if (indicator->map) {
466         return 0; /* already mapped is not an error */
467     }
468     indicator->map = indicator->addr;
469     ret = s390_io_adapter_map(adapter, indicator->map, true);
470     if ((ret != 0) && (ret != -ENOSYS)) {
471         goto out_err;
472     }
473     return 0;
474 
475 out_err:
476     indicator->map = 0;
477     return ret;
478 }
479 
480 int css_create_css_image(uint8_t cssid, bool default_image)
481 {
482     trace_css_new_image(cssid, default_image ? "(default)" : "");
483     /* 255 is reserved */
484     if (cssid == 255) {
485         return -EINVAL;
486     }
487     if (channel_subsys.css[cssid]) {
488         return -EBUSY;
489     }
490     channel_subsys.css[cssid] = g_new0(CssImage, 1);
491     if (default_image) {
492         channel_subsys.default_cssid = cssid;
493     }
494     return 0;
495 }
496 
497 uint32_t css_get_adapter_id(CssIoAdapterType type, uint8_t isc)
498 {
499     if (type >= CSS_IO_ADAPTER_TYPE_NUMS || isc > MAX_ISC ||
500         !channel_subsys.io_adapters[type][isc]) {
501         return -1;
502     }
503 
504     return channel_subsys.io_adapters[type][isc]->id;
505 }
506 
507 /**
508  * css_register_io_adapters: Register I/O adapters per ISC during init
509  *
510  * @swap: an indication if byte swap is needed.
511  * @maskable: an indication if the adapter is subject to the mask operation.
512  * @flags: further characteristics of the adapter.
513  *         e.g. suppressible, an indication if the adapter is subject to AIS.
514  * @errp: location to store error information.
515  */
516 void css_register_io_adapters(CssIoAdapterType type, bool swap, bool maskable,
517                               uint8_t flags, Error **errp)
518 {
519     uint32_t id;
520     int ret, isc;
521     IoAdapter *adapter;
522     S390FLICState *fs = s390_get_flic();
523     S390FLICStateClass *fsc = s390_get_flic_class(fs);
524 
525     /*
526      * Disallow multiple registrations for the same device type.
527      * Report an error if registering for an already registered type.
528      */
529     if (channel_subsys.io_adapters[type][0]) {
530         error_setg(errp, "Adapters for type %d already registered", type);
531     }
532 
533     for (isc = 0; isc <= MAX_ISC; isc++) {
534         id = (type << 3) | isc;
535         ret = fsc->register_io_adapter(fs, id, isc, swap, maskable, flags);
536         if (ret == 0) {
537             adapter = g_new0(IoAdapter, 1);
538             adapter->id = id;
539             adapter->isc = isc;
540             adapter->type = type;
541             adapter->flags = flags;
542             channel_subsys.io_adapters[type][isc] = adapter;
543         } else {
544             error_setg_errno(errp, -ret, "Unexpected error %d when "
545                              "registering adapter %d", ret, id);
546             break;
547         }
548     }
549 
550     /*
551      * No need to free registered adapters in kvm: kvm will clean up
552      * when the machine goes away.
553      */
554     if (ret) {
555         for (isc--; isc >= 0; isc--) {
556             g_free(channel_subsys.io_adapters[type][isc]);
557             channel_subsys.io_adapters[type][isc] = NULL;
558         }
559     }
560 
561 }
562 
563 static void css_clear_io_interrupt(uint16_t subchannel_id,
564                                    uint16_t subchannel_nr)
565 {
566     Error *err = NULL;
567     static bool no_clear_irq;
568     S390FLICState *fs = s390_get_flic();
569     S390FLICStateClass *fsc = s390_get_flic_class(fs);
570     int r;
571 
572     if (unlikely(no_clear_irq)) {
573         return;
574     }
575     r = fsc->clear_io_irq(fs, subchannel_id, subchannel_nr);
576     switch (r) {
577     case 0:
578         break;
579     case -ENOSYS:
580         no_clear_irq = true;
581         /*
582         * Ignore unavailability, as the user can't do anything
583         * about it anyway.
584         */
585         break;
586     default:
587         error_setg_errno(&err, -r, "unexpected error condition");
588         error_propagate(&error_abort, err);
589     }
590 }
591 
592 static inline uint16_t css_do_build_subchannel_id(uint8_t cssid, uint8_t ssid)
593 {
594     if (channel_subsys.max_cssid > 0) {
595         return (cssid << 8) | (1 << 3) | (ssid << 1) | 1;
596     }
597     return (ssid << 1) | 1;
598 }
599 
600 uint16_t css_build_subchannel_id(SubchDev *sch)
601 {
602     return css_do_build_subchannel_id(sch->cssid, sch->ssid);
603 }
604 
605 void css_inject_io_interrupt(SubchDev *sch)
606 {
607     uint8_t isc = (sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ISC) >> 11;
608 
609     trace_css_io_interrupt(sch->cssid, sch->ssid, sch->schid,
610                            sch->curr_status.pmcw.intparm, isc, "");
611     s390_io_interrupt(css_build_subchannel_id(sch),
612                       sch->schid,
613                       sch->curr_status.pmcw.intparm,
614                       isc << 27);
615 }
616 
617 void css_conditional_io_interrupt(SubchDev *sch)
618 {
619     /*
620      * If the subchannel is not enabled, it is not made status pending
621      * (see PoP p. 16-17, "Status Control").
622      */
623     if (!(sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA)) {
624         return;
625     }
626 
627     /*
628      * If the subchannel is not currently status pending, make it pending
629      * with alert status.
630      */
631     if (!(sch->curr_status.scsw.ctrl & SCSW_STCTL_STATUS_PEND)) {
632         uint8_t isc = (sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ISC) >> 11;
633 
634         trace_css_io_interrupt(sch->cssid, sch->ssid, sch->schid,
635                                sch->curr_status.pmcw.intparm, isc,
636                                "(unsolicited)");
637         sch->curr_status.scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
638         sch->curr_status.scsw.ctrl |=
639             SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
640         /* Inject an I/O interrupt. */
641         s390_io_interrupt(css_build_subchannel_id(sch),
642                           sch->schid,
643                           sch->curr_status.pmcw.intparm,
644                           isc << 27);
645     }
646 }
647 
648 int css_do_sic(CPUS390XState *env, uint8_t isc, uint16_t mode)
649 {
650     S390FLICState *fs = s390_get_flic();
651     S390FLICStateClass *fsc = s390_get_flic_class(fs);
652     int r;
653 
654     if (env->psw.mask & PSW_MASK_PSTATE) {
655         r = -PGM_PRIVILEGED;
656         goto out;
657     }
658 
659     trace_css_do_sic(mode, isc);
660     switch (mode) {
661     case SIC_IRQ_MODE_ALL:
662     case SIC_IRQ_MODE_SINGLE:
663         break;
664     default:
665         r = -PGM_OPERAND;
666         goto out;
667     }
668 
669     r = fsc->modify_ais_mode(fs, isc, mode) ? -PGM_OPERATION : 0;
670 out:
671     return r;
672 }
673 
674 void css_adapter_interrupt(CssIoAdapterType type, uint8_t isc)
675 {
676     S390FLICState *fs = s390_get_flic();
677     S390FLICStateClass *fsc = s390_get_flic_class(fs);
678     uint32_t io_int_word = (isc << 27) | IO_INT_WORD_AI;
679     IoAdapter *adapter = channel_subsys.io_adapters[type][isc];
680 
681     if (!adapter) {
682         return;
683     }
684 
685     trace_css_adapter_interrupt(isc);
686     if (fs->ais_supported) {
687         if (fsc->inject_airq(fs, type, isc, adapter->flags)) {
688             error_report("Failed to inject airq with AIS supported");
689             exit(1);
690         }
691     } else {
692         s390_io_interrupt(0, 0, 0, io_int_word);
693     }
694 }
695 
696 static void sch_handle_clear_func(SubchDev *sch)
697 {
698     SCHIB *schib = &sch->curr_status;
699     int path;
700 
701     /* Path management: In our simple css, we always choose the only path. */
702     path = 0x80;
703 
704     /* Reset values prior to 'issuing the clear signal'. */
705     schib->pmcw.lpum = 0;
706     schib->pmcw.pom = 0xff;
707     schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
708 
709     /* We always 'attempt to issue the clear signal', and we always succeed. */
710     sch->channel_prog = 0x0;
711     sch->last_cmd_valid = false;
712     schib->scsw.ctrl &= ~SCSW_ACTL_CLEAR_PEND;
713     schib->scsw.ctrl |= SCSW_STCTL_STATUS_PEND;
714 
715     schib->scsw.dstat = 0;
716     schib->scsw.cstat = 0;
717     schib->pmcw.lpum = path;
718 
719 }
720 
721 static void sch_handle_halt_func(SubchDev *sch)
722 {
723     SCHIB *schib = &sch->curr_status;
724     hwaddr curr_ccw = sch->channel_prog;
725     int path;
726 
727     /* Path management: In our simple css, we always choose the only path. */
728     path = 0x80;
729 
730     /* We always 'attempt to issue the halt signal', and we always succeed. */
731     sch->channel_prog = 0x0;
732     sch->last_cmd_valid = false;
733     schib->scsw.ctrl &= ~SCSW_ACTL_HALT_PEND;
734     schib->scsw.ctrl |= SCSW_STCTL_STATUS_PEND;
735 
736     if ((schib->scsw.ctrl & (SCSW_ACTL_SUBCH_ACTIVE |
737                              SCSW_ACTL_DEVICE_ACTIVE)) ||
738         !((schib->scsw.ctrl & SCSW_ACTL_START_PEND) ||
739           (schib->scsw.ctrl & SCSW_ACTL_SUSP))) {
740         schib->scsw.dstat = SCSW_DSTAT_DEVICE_END;
741     }
742     if ((schib->scsw.ctrl & (SCSW_ACTL_SUBCH_ACTIVE |
743                              SCSW_ACTL_DEVICE_ACTIVE)) ||
744         (schib->scsw.ctrl & SCSW_ACTL_SUSP)) {
745         schib->scsw.cpa = curr_ccw + 8;
746     }
747     schib->scsw.cstat = 0;
748     schib->pmcw.lpum = path;
749 
750 }
751 
752 /*
753  * As the SenseId struct cannot be packed (would cause unaligned accesses), we
754  * have to copy the individual fields to an unstructured area using the correct
755  * layout (see SA22-7204-01 "Common I/O-Device Commands").
756  */
757 static void copy_sense_id_to_guest(uint8_t *dest, SenseId *src)
758 {
759     int i;
760 
761     dest[0] = src->reserved;
762     stw_be_p(dest + 1, src->cu_type);
763     dest[3] = src->cu_model;
764     stw_be_p(dest + 4, src->dev_type);
765     dest[6] = src->dev_model;
766     dest[7] = src->unused;
767     for (i = 0; i < ARRAY_SIZE(src->ciw); i++) {
768         dest[8 + i * 4] = src->ciw[i].type;
769         dest[9 + i * 4] = src->ciw[i].command;
770         stw_be_p(dest + 10 + i * 4, src->ciw[i].count);
771     }
772 }
773 
774 static CCW1 copy_ccw_from_guest(hwaddr addr, bool fmt1)
775 {
776     CCW0 tmp0;
777     CCW1 tmp1;
778     CCW1 ret;
779 
780     if (fmt1) {
781         cpu_physical_memory_read(addr, &tmp1, sizeof(tmp1));
782         ret.cmd_code = tmp1.cmd_code;
783         ret.flags = tmp1.flags;
784         ret.count = be16_to_cpu(tmp1.count);
785         ret.cda = be32_to_cpu(tmp1.cda);
786     } else {
787         cpu_physical_memory_read(addr, &tmp0, sizeof(tmp0));
788         if ((tmp0.cmd_code & 0x0f) == CCW_CMD_TIC) {
789             ret.cmd_code = CCW_CMD_TIC;
790             ret.flags = 0;
791             ret.count = 0;
792         } else {
793             ret.cmd_code = tmp0.cmd_code;
794             ret.flags = tmp0.flags;
795             ret.count = be16_to_cpu(tmp0.count);
796         }
797         ret.cda = be16_to_cpu(tmp0.cda1) | (tmp0.cda0 << 16);
798     }
799     return ret;
800 }
801 /**
802  * If out of bounds marks the stream broken. If broken returns -EINVAL,
803  * otherwise the requested length (may be zero)
804  */
805 static inline int cds_check_len(CcwDataStream *cds, int len)
806 {
807     if (cds->at_byte + len > cds->count) {
808         cds->flags |= CDS_F_STREAM_BROKEN;
809     }
810     return cds->flags & CDS_F_STREAM_BROKEN ? -EINVAL : len;
811 }
812 
813 static inline bool cds_ccw_addrs_ok(hwaddr addr, int len, bool ccw_fmt1)
814 {
815     return (addr + len) < (ccw_fmt1 ? (1UL << 31) : (1UL << 24));
816 }
817 
818 static int ccw_dstream_rw_noflags(CcwDataStream *cds, void *buff, int len,
819                                   CcwDataStreamOp op)
820 {
821     int ret;
822 
823     ret = cds_check_len(cds, len);
824     if (ret <= 0) {
825         return ret;
826     }
827     if (!cds_ccw_addrs_ok(cds->cda, len, cds->flags & CDS_F_FMT)) {
828         return -EINVAL; /* channel program check */
829     }
830     if (op == CDS_OP_A) {
831         goto incr;
832     }
833     ret = address_space_rw(&address_space_memory, cds->cda,
834                            MEMTXATTRS_UNSPECIFIED, buff, len, op);
835     if (ret != MEMTX_OK) {
836         cds->flags |= CDS_F_STREAM_BROKEN;
837         return -EINVAL;
838     }
839 incr:
840     cds->at_byte += len;
841     cds->cda += len;
842     return 0;
843 }
844 
845 /* returns values between 1 and bsz, where bsz is a power of 2 */
846 static inline uint16_t ida_continuous_left(hwaddr cda, uint64_t bsz)
847 {
848     return bsz - (cda & (bsz - 1));
849 }
850 
851 static inline uint64_t ccw_ida_block_size(uint8_t flags)
852 {
853     if ((flags & CDS_F_C64) && !(flags & CDS_F_I2K)) {
854         return 1ULL << 12;
855     }
856     return 1ULL << 11;
857 }
858 
859 static inline int ida_read_next_idaw(CcwDataStream *cds)
860 {
861     union {uint64_t fmt2; uint32_t fmt1; } idaw;
862     int ret;
863     hwaddr idaw_addr;
864     bool idaw_fmt2 = cds->flags & CDS_F_C64;
865     bool ccw_fmt1 = cds->flags & CDS_F_FMT;
866 
867     if (idaw_fmt2) {
868         idaw_addr = cds->cda_orig + sizeof(idaw.fmt2) * cds->at_idaw;
869         if (idaw_addr & 0x07 || !cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
870             return -EINVAL; /* channel program check */
871         }
872         ret = address_space_rw(&address_space_memory, idaw_addr,
873                                MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt2,
874                                sizeof(idaw.fmt2), false);
875         cds->cda = be64_to_cpu(idaw.fmt2);
876     } else {
877         idaw_addr = cds->cda_orig + sizeof(idaw.fmt1) * cds->at_idaw;
878         if (idaw_addr & 0x03 || !cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
879             return -EINVAL; /* channel program check */
880         }
881         ret = address_space_rw(&address_space_memory, idaw_addr,
882                                MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt1,
883                                sizeof(idaw.fmt1), false);
884         cds->cda = be64_to_cpu(idaw.fmt1);
885         if (cds->cda & 0x80000000) {
886             return -EINVAL; /* channel program check */
887         }
888     }
889     ++(cds->at_idaw);
890     if (ret != MEMTX_OK) {
891         /* assume inaccessible address */
892         return -EINVAL; /* channel program check */
893     }
894     return 0;
895 }
896 
897 static int ccw_dstream_rw_ida(CcwDataStream *cds, void *buff, int len,
898                               CcwDataStreamOp op)
899 {
900     uint64_t bsz = ccw_ida_block_size(cds->flags);
901     int ret = 0;
902     uint16_t cont_left, iter_len;
903 
904     ret = cds_check_len(cds, len);
905     if (ret <= 0) {
906         return ret;
907     }
908     if (!cds->at_idaw) {
909         /* read first idaw */
910         ret = ida_read_next_idaw(cds);
911         if (ret) {
912             goto err;
913         }
914         cont_left = ida_continuous_left(cds->cda, bsz);
915     } else {
916         cont_left = ida_continuous_left(cds->cda, bsz);
917         if (cont_left == bsz) {
918             ret = ida_read_next_idaw(cds);
919             if (ret) {
920                 goto err;
921             }
922             if (cds->cda & (bsz - 1)) {
923                 ret = -EINVAL; /* channel program check */
924                 goto err;
925             }
926         }
927     }
928     do {
929         iter_len = MIN(len, cont_left);
930         if (op != CDS_OP_A) {
931             ret = address_space_rw(&address_space_memory, cds->cda,
932                                    MEMTXATTRS_UNSPECIFIED, buff, iter_len, op);
933             if (ret != MEMTX_OK) {
934                 /* assume inaccessible address */
935                 ret = -EINVAL; /* channel program check */
936                 goto err;
937             }
938         }
939         cds->at_byte += iter_len;
940         cds->cda += iter_len;
941         len -= iter_len;
942         if (!len) {
943             break;
944         }
945         ret = ida_read_next_idaw(cds);
946         if (ret) {
947             goto err;
948         }
949         cont_left = bsz;
950     } while (true);
951     return ret;
952 err:
953     cds->flags |= CDS_F_STREAM_BROKEN;
954     return ret;
955 }
956 
957 void ccw_dstream_init(CcwDataStream *cds, CCW1 const *ccw, ORB const *orb)
958 {
959     /*
960      * We don't support MIDA (an optional facility) yet and we
961      * catch this earlier. Just for expressing the precondition.
962      */
963     g_assert(!(orb->ctrl1 & ORB_CTRL1_MASK_MIDAW));
964     cds->flags = (orb->ctrl0 & ORB_CTRL0_MASK_I2K ? CDS_F_I2K : 0) |
965                  (orb->ctrl0 & ORB_CTRL0_MASK_C64 ? CDS_F_C64 : 0) |
966                  (orb->ctrl0 & ORB_CTRL0_MASK_FMT ? CDS_F_FMT : 0) |
967                  (ccw->flags & CCW_FLAG_IDA ? CDS_F_IDA : 0);
968 
969     cds->count = ccw->count;
970     cds->cda_orig = ccw->cda;
971     ccw_dstream_rewind(cds);
972     if (!(cds->flags & CDS_F_IDA)) {
973         cds->op_handler = ccw_dstream_rw_noflags;
974     } else {
975         cds->op_handler = ccw_dstream_rw_ida;
976     }
977 }
978 
979 static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
980                              bool suspend_allowed)
981 {
982     int ret;
983     bool check_len;
984     int len;
985     CCW1 ccw;
986 
987     if (!ccw_addr) {
988         return -EINVAL; /* channel-program check */
989     }
990     /* Check doubleword aligned and 31 or 24 (fmt 0) bit addressable. */
991     if (ccw_addr & (sch->ccw_fmt_1 ? 0x80000007 : 0xff000007)) {
992         return -EINVAL;
993     }
994 
995     /* Translate everything to format-1 ccws - the information is the same. */
996     ccw = copy_ccw_from_guest(ccw_addr, sch->ccw_fmt_1);
997 
998     /* Check for invalid command codes. */
999     if ((ccw.cmd_code & 0x0f) == 0) {
1000         return -EINVAL;
1001     }
1002     if (((ccw.cmd_code & 0x0f) == CCW_CMD_TIC) &&
1003         ((ccw.cmd_code & 0xf0) != 0)) {
1004         return -EINVAL;
1005     }
1006     if (!sch->ccw_fmt_1 && (ccw.count == 0) &&
1007         (ccw.cmd_code != CCW_CMD_TIC)) {
1008         return -EINVAL;
1009     }
1010 
1011     /* We don't support MIDA. */
1012     if (ccw.flags & CCW_FLAG_MIDA) {
1013         return -EINVAL;
1014     }
1015 
1016     if (ccw.flags & CCW_FLAG_SUSPEND) {
1017         return suspend_allowed ? -EINPROGRESS : -EINVAL;
1018     }
1019 
1020     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
1021 
1022     if (!ccw.cda) {
1023         if (sch->ccw_no_data_cnt == 255) {
1024             return -EINVAL;
1025         }
1026         sch->ccw_no_data_cnt++;
1027     }
1028 
1029     /* Look at the command. */
1030     ccw_dstream_init(&sch->cds, &ccw, &(sch->orb));
1031     switch (ccw.cmd_code) {
1032     case CCW_CMD_NOOP:
1033         /* Nothing to do. */
1034         ret = 0;
1035         break;
1036     case CCW_CMD_BASIC_SENSE:
1037         if (check_len) {
1038             if (ccw.count != sizeof(sch->sense_data)) {
1039                 ret = -EINVAL;
1040                 break;
1041             }
1042         }
1043         len = MIN(ccw.count, sizeof(sch->sense_data));
1044         ccw_dstream_write_buf(&sch->cds, sch->sense_data, len);
1045         sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
1046         memset(sch->sense_data, 0, sizeof(sch->sense_data));
1047         ret = 0;
1048         break;
1049     case CCW_CMD_SENSE_ID:
1050     {
1051         /* According to SA22-7204-01, Sense-ID can store up to 256 bytes */
1052         uint8_t sense_id[256];
1053 
1054         copy_sense_id_to_guest(sense_id, &sch->id);
1055         /* Sense ID information is device specific. */
1056         if (check_len) {
1057             if (ccw.count != sizeof(sense_id)) {
1058                 ret = -EINVAL;
1059                 break;
1060             }
1061         }
1062         len = MIN(ccw.count, sizeof(sense_id));
1063         /*
1064          * Only indicate 0xff in the first sense byte if we actually
1065          * have enough place to store at least bytes 0-3.
1066          */
1067         if (len >= 4) {
1068             sense_id[0] = 0xff;
1069         } else {
1070             sense_id[0] = 0;
1071         }
1072         ccw_dstream_write_buf(&sch->cds, sense_id, len);
1073         sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
1074         ret = 0;
1075         break;
1076     }
1077     case CCW_CMD_TIC:
1078         if (sch->last_cmd_valid && (sch->last_cmd.cmd_code == CCW_CMD_TIC)) {
1079             ret = -EINVAL;
1080             break;
1081         }
1082         if (ccw.flags || ccw.count) {
1083             /* We have already sanitized these if converted from fmt 0. */
1084             ret = -EINVAL;
1085             break;
1086         }
1087         sch->channel_prog = ccw.cda;
1088         ret = -EAGAIN;
1089         break;
1090     default:
1091         if (sch->ccw_cb) {
1092             /* Handle device specific commands. */
1093             ret = sch->ccw_cb(sch, ccw);
1094         } else {
1095             ret = -ENOSYS;
1096         }
1097         break;
1098     }
1099     sch->last_cmd = ccw;
1100     sch->last_cmd_valid = true;
1101     if (ret == 0) {
1102         if (ccw.flags & CCW_FLAG_CC) {
1103             sch->channel_prog += 8;
1104             ret = -EAGAIN;
1105         }
1106     }
1107 
1108     return ret;
1109 }
1110 
1111 static void sch_handle_start_func_virtual(SubchDev *sch)
1112 {
1113     SCHIB *schib = &sch->curr_status;
1114     int path;
1115     int ret;
1116     bool suspend_allowed;
1117 
1118     /* Path management: In our simple css, we always choose the only path. */
1119     path = 0x80;
1120 
1121     if (!(schib->scsw.ctrl & SCSW_ACTL_SUSP)) {
1122         /* Start Function triggered via ssch, i.e. we have an ORB */
1123         ORB *orb = &sch->orb;
1124         schib->scsw.cstat = 0;
1125         schib->scsw.dstat = 0;
1126         /* Look at the orb and try to execute the channel program. */
1127         schib->pmcw.intparm = orb->intparm;
1128         if (!(orb->lpm & path)) {
1129             /* Generate a deferred cc 3 condition. */
1130             schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
1131             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1132             schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
1133             return;
1134         }
1135         sch->ccw_fmt_1 = !!(orb->ctrl0 & ORB_CTRL0_MASK_FMT);
1136         schib->scsw.flags |= (sch->ccw_fmt_1) ? SCSW_FLAGS_MASK_FMT : 0;
1137         sch->ccw_no_data_cnt = 0;
1138         suspend_allowed = !!(orb->ctrl0 & ORB_CTRL0_MASK_SPND);
1139     } else {
1140         /* Start Function resumed via rsch */
1141         schib->scsw.ctrl &= ~(SCSW_ACTL_SUSP | SCSW_ACTL_RESUME_PEND);
1142         /* The channel program had been suspended before. */
1143         suspend_allowed = true;
1144     }
1145     sch->last_cmd_valid = false;
1146     do {
1147         ret = css_interpret_ccw(sch, sch->channel_prog, suspend_allowed);
1148         switch (ret) {
1149         case -EAGAIN:
1150             /* ccw chain, continue processing */
1151             break;
1152         case 0:
1153             /* success */
1154             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1155             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1156             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
1157                     SCSW_STCTL_STATUS_PEND;
1158             schib->scsw.dstat = SCSW_DSTAT_CHANNEL_END | SCSW_DSTAT_DEVICE_END;
1159             schib->scsw.cpa = sch->channel_prog + 8;
1160             break;
1161         case -EIO:
1162             /* I/O errors, status depends on specific devices */
1163             break;
1164         case -ENOSYS:
1165             /* unsupported command, generate unit check (command reject) */
1166             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1167             schib->scsw.dstat = SCSW_DSTAT_UNIT_CHECK;
1168             /* Set sense bit 0 in ecw0. */
1169             sch->sense_data[0] = 0x80;
1170             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1171             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
1172                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
1173             schib->scsw.cpa = sch->channel_prog + 8;
1174             break;
1175         case -EINPROGRESS:
1176             /* channel program has been suspended */
1177             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1178             schib->scsw.ctrl |= SCSW_ACTL_SUSP;
1179             break;
1180         default:
1181             /* error, generate channel program check */
1182             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1183             schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
1184             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1185             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
1186                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
1187             schib->scsw.cpa = sch->channel_prog + 8;
1188             break;
1189         }
1190     } while (ret == -EAGAIN);
1191 
1192 }
1193 
1194 static IOInstEnding sch_handle_start_func_passthrough(SubchDev *sch)
1195 {
1196     SCHIB *schib = &sch->curr_status;
1197     ORB *orb = &sch->orb;
1198     if (!(schib->scsw.ctrl & SCSW_ACTL_SUSP)) {
1199         assert(orb != NULL);
1200         schib->pmcw.intparm = orb->intparm;
1201     }
1202     return s390_ccw_cmd_request(sch);
1203 }
1204 
1205 /*
1206  * On real machines, this would run asynchronously to the main vcpus.
1207  * We might want to make some parts of the ssch handling (interpreting
1208  * read/writes) asynchronous later on if we start supporting more than
1209  * our current very simple devices.
1210  */
1211 IOInstEnding do_subchannel_work_virtual(SubchDev *sch)
1212 {
1213     SCHIB *schib = &sch->curr_status;
1214 
1215     if (schib->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {
1216         sch_handle_clear_func(sch);
1217     } else if (schib->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {
1218         sch_handle_halt_func(sch);
1219     } else if (schib->scsw.ctrl & SCSW_FCTL_START_FUNC) {
1220         /* Triggered by both ssch and rsch. */
1221         sch_handle_start_func_virtual(sch);
1222     }
1223     css_inject_io_interrupt(sch);
1224     /* inst must succeed if this func is called */
1225     return IOINST_CC_EXPECTED;
1226 }
1227 
1228 IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
1229 {
1230     SCHIB *schib = &sch->curr_status;
1231 
1232     if (schib->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {
1233         /* TODO: Clear handling */
1234         sch_handle_clear_func(sch);
1235     } else if (schib->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {
1236         /* TODO: Halt handling */
1237         sch_handle_halt_func(sch);
1238     } else if (schib->scsw.ctrl & SCSW_FCTL_START_FUNC) {
1239         return sch_handle_start_func_passthrough(sch);
1240     }
1241     return IOINST_CC_EXPECTED;
1242 }
1243 
1244 static IOInstEnding do_subchannel_work(SubchDev *sch)
1245 {
1246     if (!sch->do_subchannel_work) {
1247         return IOINST_CC_STATUS_PRESENT;
1248     }
1249     g_assert(sch->curr_status.scsw.ctrl & SCSW_CTRL_MASK_FCTL);
1250     return sch->do_subchannel_work(sch);
1251 }
1252 
1253 static void copy_pmcw_to_guest(PMCW *dest, const PMCW *src)
1254 {
1255     int i;
1256 
1257     dest->intparm = cpu_to_be32(src->intparm);
1258     dest->flags = cpu_to_be16(src->flags);
1259     dest->devno = cpu_to_be16(src->devno);
1260     dest->lpm = src->lpm;
1261     dest->pnom = src->pnom;
1262     dest->lpum = src->lpum;
1263     dest->pim = src->pim;
1264     dest->mbi = cpu_to_be16(src->mbi);
1265     dest->pom = src->pom;
1266     dest->pam = src->pam;
1267     for (i = 0; i < ARRAY_SIZE(dest->chpid); i++) {
1268         dest->chpid[i] = src->chpid[i];
1269     }
1270     dest->chars = cpu_to_be32(src->chars);
1271 }
1272 
1273 void copy_scsw_to_guest(SCSW *dest, const SCSW *src)
1274 {
1275     dest->flags = cpu_to_be16(src->flags);
1276     dest->ctrl = cpu_to_be16(src->ctrl);
1277     dest->cpa = cpu_to_be32(src->cpa);
1278     dest->dstat = src->dstat;
1279     dest->cstat = src->cstat;
1280     dest->count = cpu_to_be16(src->count);
1281 }
1282 
1283 static void copy_schib_to_guest(SCHIB *dest, const SCHIB *src)
1284 {
1285     int i;
1286     /*
1287      * We copy the PMCW and SCSW in and out of local variables to
1288      * avoid taking the address of members of a packed struct.
1289      */
1290     PMCW src_pmcw, dest_pmcw;
1291     SCSW src_scsw, dest_scsw;
1292 
1293     src_pmcw = src->pmcw;
1294     copy_pmcw_to_guest(&dest_pmcw, &src_pmcw);
1295     dest->pmcw = dest_pmcw;
1296     src_scsw = src->scsw;
1297     copy_scsw_to_guest(&dest_scsw, &src_scsw);
1298     dest->scsw = dest_scsw;
1299     dest->mba = cpu_to_be64(src->mba);
1300     for (i = 0; i < ARRAY_SIZE(dest->mda); i++) {
1301         dest->mda[i] = src->mda[i];
1302     }
1303 }
1304 
1305 int css_do_stsch(SubchDev *sch, SCHIB *schib)
1306 {
1307     /* Use current status. */
1308     copy_schib_to_guest(schib, &sch->curr_status);
1309     return 0;
1310 }
1311 
1312 static void copy_pmcw_from_guest(PMCW *dest, const PMCW *src)
1313 {
1314     int i;
1315 
1316     dest->intparm = be32_to_cpu(src->intparm);
1317     dest->flags = be16_to_cpu(src->flags);
1318     dest->devno = be16_to_cpu(src->devno);
1319     dest->lpm = src->lpm;
1320     dest->pnom = src->pnom;
1321     dest->lpum = src->lpum;
1322     dest->pim = src->pim;
1323     dest->mbi = be16_to_cpu(src->mbi);
1324     dest->pom = src->pom;
1325     dest->pam = src->pam;
1326     for (i = 0; i < ARRAY_SIZE(dest->chpid); i++) {
1327         dest->chpid[i] = src->chpid[i];
1328     }
1329     dest->chars = be32_to_cpu(src->chars);
1330 }
1331 
1332 static void copy_scsw_from_guest(SCSW *dest, const SCSW *src)
1333 {
1334     dest->flags = be16_to_cpu(src->flags);
1335     dest->ctrl = be16_to_cpu(src->ctrl);
1336     dest->cpa = be32_to_cpu(src->cpa);
1337     dest->dstat = src->dstat;
1338     dest->cstat = src->cstat;
1339     dest->count = be16_to_cpu(src->count);
1340 }
1341 
1342 static void copy_schib_from_guest(SCHIB *dest, const SCHIB *src)
1343 {
1344     int i;
1345     /*
1346      * We copy the PMCW and SCSW in and out of local variables to
1347      * avoid taking the address of members of a packed struct.
1348      */
1349     PMCW src_pmcw, dest_pmcw;
1350     SCSW src_scsw, dest_scsw;
1351 
1352     src_pmcw = src->pmcw;
1353     copy_pmcw_from_guest(&dest_pmcw, &src_pmcw);
1354     dest->pmcw = dest_pmcw;
1355     src_scsw = src->scsw;
1356     copy_scsw_from_guest(&dest_scsw, &src_scsw);
1357     dest->scsw = dest_scsw;
1358     dest->mba = be64_to_cpu(src->mba);
1359     for (i = 0; i < ARRAY_SIZE(dest->mda); i++) {
1360         dest->mda[i] = src->mda[i];
1361     }
1362 }
1363 
1364 IOInstEnding css_do_msch(SubchDev *sch, const SCHIB *orig_schib)
1365 {
1366     SCHIB *schib = &sch->curr_status;
1367     uint16_t oldflags;
1368     SCHIB schib_copy;
1369 
1370     if (!(schib->pmcw.flags & PMCW_FLAGS_MASK_DNV)) {
1371         return IOINST_CC_EXPECTED;
1372     }
1373 
1374     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1375         return IOINST_CC_STATUS_PRESENT;
1376     }
1377 
1378     if (schib->scsw.ctrl &
1379         (SCSW_FCTL_START_FUNC|SCSW_FCTL_HALT_FUNC|SCSW_FCTL_CLEAR_FUNC)) {
1380         return IOINST_CC_BUSY;
1381     }
1382 
1383     copy_schib_from_guest(&schib_copy, orig_schib);
1384     /* Only update the program-modifiable fields. */
1385     schib->pmcw.intparm = schib_copy.pmcw.intparm;
1386     oldflags = schib->pmcw.flags;
1387     schib->pmcw.flags &= ~(PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
1388                   PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
1389                   PMCW_FLAGS_MASK_MP);
1390     schib->pmcw.flags |= schib_copy.pmcw.flags &
1391             (PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
1392              PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
1393              PMCW_FLAGS_MASK_MP);
1394     schib->pmcw.lpm = schib_copy.pmcw.lpm;
1395     schib->pmcw.mbi = schib_copy.pmcw.mbi;
1396     schib->pmcw.pom = schib_copy.pmcw.pom;
1397     schib->pmcw.chars &= ~(PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_CSENSE);
1398     schib->pmcw.chars |= schib_copy.pmcw.chars &
1399             (PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_CSENSE);
1400     schib->mba = schib_copy.mba;
1401 
1402     /* Has the channel been disabled? */
1403     if (sch->disable_cb && (oldflags & PMCW_FLAGS_MASK_ENA) != 0
1404         && (schib->pmcw.flags & PMCW_FLAGS_MASK_ENA) == 0) {
1405         sch->disable_cb(sch);
1406     }
1407     return IOINST_CC_EXPECTED;
1408 }
1409 
1410 IOInstEnding css_do_xsch(SubchDev *sch)
1411 {
1412     SCHIB *schib = &sch->curr_status;
1413 
1414     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1415         return IOINST_CC_NOT_OPERATIONAL;
1416     }
1417 
1418     if (schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) {
1419         return IOINST_CC_STATUS_PRESENT;
1420     }
1421 
1422     if (!(schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) ||
1423         ((schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) != SCSW_FCTL_START_FUNC) ||
1424         (!(schib->scsw.ctrl &
1425            (SCSW_ACTL_RESUME_PEND | SCSW_ACTL_START_PEND | SCSW_ACTL_SUSP))) ||
1426         (schib->scsw.ctrl & SCSW_ACTL_SUBCH_ACTIVE)) {
1427         return IOINST_CC_BUSY;
1428     }
1429 
1430     /* Cancel the current operation. */
1431     schib->scsw.ctrl &= ~(SCSW_FCTL_START_FUNC |
1432                  SCSW_ACTL_RESUME_PEND |
1433                  SCSW_ACTL_START_PEND |
1434                  SCSW_ACTL_SUSP);
1435     sch->channel_prog = 0x0;
1436     sch->last_cmd_valid = false;
1437     schib->scsw.dstat = 0;
1438     schib->scsw.cstat = 0;
1439     return IOINST_CC_EXPECTED;
1440 }
1441 
1442 IOInstEnding css_do_csch(SubchDev *sch)
1443 {
1444     SCHIB *schib = &sch->curr_status;
1445 
1446     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1447         return IOINST_CC_NOT_OPERATIONAL;
1448     }
1449 
1450     /* Trigger the clear function. */
1451     schib->scsw.ctrl &= ~(SCSW_CTRL_MASK_FCTL | SCSW_CTRL_MASK_ACTL);
1452     schib->scsw.ctrl |= SCSW_FCTL_CLEAR_FUNC | SCSW_ACTL_CLEAR_PEND;
1453 
1454     return do_subchannel_work(sch);
1455 }
1456 
1457 IOInstEnding css_do_hsch(SubchDev *sch)
1458 {
1459     SCHIB *schib = &sch->curr_status;
1460 
1461     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1462         return IOINST_CC_NOT_OPERATIONAL;
1463     }
1464 
1465     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) == SCSW_STCTL_STATUS_PEND) ||
1466         (schib->scsw.ctrl & (SCSW_STCTL_PRIMARY |
1467                     SCSW_STCTL_SECONDARY |
1468                     SCSW_STCTL_ALERT))) {
1469         return IOINST_CC_STATUS_PRESENT;
1470     }
1471 
1472     if (schib->scsw.ctrl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
1473         return IOINST_CC_BUSY;
1474     }
1475 
1476     /* Trigger the halt function. */
1477     schib->scsw.ctrl |= SCSW_FCTL_HALT_FUNC;
1478     schib->scsw.ctrl &= ~SCSW_FCTL_START_FUNC;
1479     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_ACTL) ==
1480          (SCSW_ACTL_SUBCH_ACTIVE | SCSW_ACTL_DEVICE_ACTIVE)) &&
1481         ((schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) ==
1482          SCSW_STCTL_INTERMEDIATE)) {
1483         schib->scsw.ctrl &= ~SCSW_STCTL_STATUS_PEND;
1484     }
1485     schib->scsw.ctrl |= SCSW_ACTL_HALT_PEND;
1486 
1487     return do_subchannel_work(sch);
1488 }
1489 
1490 static void css_update_chnmon(SubchDev *sch)
1491 {
1492     if (!(sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_MME)) {
1493         /* Not active. */
1494         return;
1495     }
1496     /* The counter is conveniently located at the beginning of the struct. */
1497     if (sch->curr_status.pmcw.chars & PMCW_CHARS_MASK_MBFC) {
1498         /* Format 1, per-subchannel area. */
1499         uint32_t count;
1500 
1501         count = address_space_ldl(&address_space_memory,
1502                                   sch->curr_status.mba,
1503                                   MEMTXATTRS_UNSPECIFIED,
1504                                   NULL);
1505         count++;
1506         address_space_stl(&address_space_memory, sch->curr_status.mba, count,
1507                           MEMTXATTRS_UNSPECIFIED, NULL);
1508     } else {
1509         /* Format 0, global area. */
1510         uint32_t offset;
1511         uint16_t count;
1512 
1513         offset = sch->curr_status.pmcw.mbi << 5;
1514         count = address_space_lduw(&address_space_memory,
1515                                    channel_subsys.chnmon_area + offset,
1516                                    MEMTXATTRS_UNSPECIFIED,
1517                                    NULL);
1518         count++;
1519         address_space_stw(&address_space_memory,
1520                           channel_subsys.chnmon_area + offset, count,
1521                           MEMTXATTRS_UNSPECIFIED, NULL);
1522     }
1523 }
1524 
1525 IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb)
1526 {
1527     SCHIB *schib = &sch->curr_status;
1528 
1529     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1530         return IOINST_CC_NOT_OPERATIONAL;
1531     }
1532 
1533     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1534         return IOINST_CC_STATUS_PRESENT;
1535     }
1536 
1537     if (schib->scsw.ctrl & (SCSW_FCTL_START_FUNC |
1538                    SCSW_FCTL_HALT_FUNC |
1539                    SCSW_FCTL_CLEAR_FUNC)) {
1540         return IOINST_CC_BUSY;
1541     }
1542 
1543     /* If monitoring is active, update counter. */
1544     if (channel_subsys.chnmon_active) {
1545         css_update_chnmon(sch);
1546     }
1547     sch->orb = *orb;
1548     sch->channel_prog = orb->cpa;
1549     /* Trigger the start function. */
1550     schib->scsw.ctrl |= (SCSW_FCTL_START_FUNC | SCSW_ACTL_START_PEND);
1551     schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1552 
1553     return do_subchannel_work(sch);
1554 }
1555 
1556 static void copy_irb_to_guest(IRB *dest, const IRB *src, const PMCW *pmcw,
1557                               int *irb_len)
1558 {
1559     int i;
1560     uint16_t stctl = src->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1561     uint16_t actl = src->scsw.ctrl & SCSW_CTRL_MASK_ACTL;
1562 
1563     copy_scsw_to_guest(&dest->scsw, &src->scsw);
1564 
1565     for (i = 0; i < ARRAY_SIZE(dest->esw); i++) {
1566         dest->esw[i] = cpu_to_be32(src->esw[i]);
1567     }
1568     for (i = 0; i < ARRAY_SIZE(dest->ecw); i++) {
1569         dest->ecw[i] = cpu_to_be32(src->ecw[i]);
1570     }
1571     *irb_len = sizeof(*dest) - sizeof(dest->emw);
1572 
1573     /* extended measurements enabled? */
1574     if ((src->scsw.flags & SCSW_FLAGS_MASK_ESWF) ||
1575         !(pmcw->flags & PMCW_FLAGS_MASK_TF) ||
1576         !(pmcw->chars & PMCW_CHARS_MASK_XMWME)) {
1577         return;
1578     }
1579     /* extended measurements pending? */
1580     if (!(stctl & SCSW_STCTL_STATUS_PEND)) {
1581         return;
1582     }
1583     if ((stctl & SCSW_STCTL_PRIMARY) ||
1584         (stctl == SCSW_STCTL_SECONDARY) ||
1585         ((stctl & SCSW_STCTL_INTERMEDIATE) && (actl & SCSW_ACTL_SUSP))) {
1586         for (i = 0; i < ARRAY_SIZE(dest->emw); i++) {
1587             dest->emw[i] = cpu_to_be32(src->emw[i]);
1588         }
1589     }
1590     *irb_len = sizeof(*dest);
1591 }
1592 
1593 int css_do_tsch_get_irb(SubchDev *sch, IRB *target_irb, int *irb_len)
1594 {
1595     SCHIB *schib = &sch->curr_status;
1596     PMCW p;
1597     uint16_t stctl;
1598     IRB irb;
1599 
1600     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1601         return 3;
1602     }
1603 
1604     stctl = schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1605 
1606     /* Prepare the irb for the guest. */
1607     memset(&irb, 0, sizeof(IRB));
1608 
1609     /* Copy scsw from current status. */
1610     irb.scsw = schib->scsw;
1611     if (stctl & SCSW_STCTL_STATUS_PEND) {
1612         if (schib->scsw.cstat & (SCSW_CSTAT_DATA_CHECK |
1613                         SCSW_CSTAT_CHN_CTRL_CHK |
1614                         SCSW_CSTAT_INTF_CTRL_CHK)) {
1615             irb.scsw.flags |= SCSW_FLAGS_MASK_ESWF;
1616             irb.esw[0] = 0x04804000;
1617         } else {
1618             irb.esw[0] = 0x00800000;
1619         }
1620         /* If a unit check is pending, copy sense data. */
1621         if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
1622             (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
1623             int i;
1624 
1625             irb.scsw.flags |= SCSW_FLAGS_MASK_ESWF | SCSW_FLAGS_MASK_ECTL;
1626             /* Attention: sense_data is already BE! */
1627             memcpy(irb.ecw, sch->sense_data, sizeof(sch->sense_data));
1628             for (i = 0; i < ARRAY_SIZE(irb.ecw); i++) {
1629                 irb.ecw[i] = be32_to_cpu(irb.ecw[i]);
1630             }
1631             irb.esw[1] = 0x01000000 | (sizeof(sch->sense_data) << 8);
1632         }
1633     }
1634     /* Store the irb to the guest. */
1635     p = schib->pmcw;
1636     copy_irb_to_guest(target_irb, &irb, &p, irb_len);
1637 
1638     return ((stctl & SCSW_STCTL_STATUS_PEND) == 0);
1639 }
1640 
1641 void css_do_tsch_update_subch(SubchDev *sch)
1642 {
1643     SCHIB *schib = &sch->curr_status;
1644     uint16_t stctl;
1645     uint16_t fctl;
1646     uint16_t actl;
1647 
1648     stctl = schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1649     fctl = schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL;
1650     actl = schib->scsw.ctrl & SCSW_CTRL_MASK_ACTL;
1651 
1652     /* Clear conditions on subchannel, if applicable. */
1653     if (stctl & SCSW_STCTL_STATUS_PEND) {
1654         schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1655         if ((stctl != (SCSW_STCTL_INTERMEDIATE | SCSW_STCTL_STATUS_PEND)) ||
1656             ((fctl & SCSW_FCTL_HALT_FUNC) &&
1657              (actl & SCSW_ACTL_SUSP))) {
1658             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_FCTL;
1659         }
1660         if (stctl != (SCSW_STCTL_INTERMEDIATE | SCSW_STCTL_STATUS_PEND)) {
1661             schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1662             schib->scsw.ctrl &= ~(SCSW_ACTL_RESUME_PEND |
1663                          SCSW_ACTL_START_PEND |
1664                          SCSW_ACTL_HALT_PEND |
1665                          SCSW_ACTL_CLEAR_PEND |
1666                          SCSW_ACTL_SUSP);
1667         } else {
1668             if ((actl & SCSW_ACTL_SUSP) &&
1669                 (fctl & SCSW_FCTL_START_FUNC)) {
1670                 schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1671                 if (fctl & SCSW_FCTL_HALT_FUNC) {
1672                     schib->scsw.ctrl &= ~(SCSW_ACTL_RESUME_PEND |
1673                                  SCSW_ACTL_START_PEND |
1674                                  SCSW_ACTL_HALT_PEND |
1675                                  SCSW_ACTL_CLEAR_PEND |
1676                                  SCSW_ACTL_SUSP);
1677                 } else {
1678                     schib->scsw.ctrl &= ~SCSW_ACTL_RESUME_PEND;
1679                 }
1680             }
1681         }
1682         /* Clear pending sense data. */
1683         if (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE) {
1684             memset(sch->sense_data, 0 , sizeof(sch->sense_data));
1685         }
1686     }
1687 }
1688 
1689 static void copy_crw_to_guest(CRW *dest, const CRW *src)
1690 {
1691     dest->flags = cpu_to_be16(src->flags);
1692     dest->rsid = cpu_to_be16(src->rsid);
1693 }
1694 
1695 int css_do_stcrw(CRW *crw)
1696 {
1697     CrwContainer *crw_cont;
1698     int ret;
1699 
1700     crw_cont = QTAILQ_FIRST(&channel_subsys.pending_crws);
1701     if (crw_cont) {
1702         QTAILQ_REMOVE(&channel_subsys.pending_crws, crw_cont, sibling);
1703         copy_crw_to_guest(crw, &crw_cont->crw);
1704         g_free(crw_cont);
1705         ret = 0;
1706     } else {
1707         /* List was empty, turn crw machine checks on again. */
1708         memset(crw, 0, sizeof(*crw));
1709         channel_subsys.do_crw_mchk = true;
1710         ret = 1;
1711     }
1712 
1713     return ret;
1714 }
1715 
1716 static void copy_crw_from_guest(CRW *dest, const CRW *src)
1717 {
1718     dest->flags = be16_to_cpu(src->flags);
1719     dest->rsid = be16_to_cpu(src->rsid);
1720 }
1721 
1722 void css_undo_stcrw(CRW *crw)
1723 {
1724     CrwContainer *crw_cont;
1725 
1726     crw_cont = g_try_new0(CrwContainer, 1);
1727     if (!crw_cont) {
1728         channel_subsys.crws_lost = true;
1729         return;
1730     }
1731     copy_crw_from_guest(&crw_cont->crw, crw);
1732 
1733     QTAILQ_INSERT_HEAD(&channel_subsys.pending_crws, crw_cont, sibling);
1734 }
1735 
1736 int css_collect_chp_desc(int m, uint8_t cssid, uint8_t f_chpid, uint8_t l_chpid,
1737                          int rfmt, void *buf)
1738 {
1739     int i, desc_size;
1740     uint32_t words[8];
1741     uint32_t chpid_type_word;
1742     CssImage *css;
1743 
1744     if (!m && !cssid) {
1745         css = channel_subsys.css[channel_subsys.default_cssid];
1746     } else {
1747         css = channel_subsys.css[cssid];
1748     }
1749     if (!css) {
1750         return 0;
1751     }
1752     desc_size = 0;
1753     for (i = f_chpid; i <= l_chpid; i++) {
1754         if (css->chpids[i].in_use) {
1755             chpid_type_word = 0x80000000 | (css->chpids[i].type << 8) | i;
1756             if (rfmt == 0) {
1757                 words[0] = cpu_to_be32(chpid_type_word);
1758                 words[1] = 0;
1759                 memcpy(buf + desc_size, words, 8);
1760                 desc_size += 8;
1761             } else if (rfmt == 1) {
1762                 words[0] = cpu_to_be32(chpid_type_word);
1763                 words[1] = 0;
1764                 words[2] = 0;
1765                 words[3] = 0;
1766                 words[4] = 0;
1767                 words[5] = 0;
1768                 words[6] = 0;
1769                 words[7] = 0;
1770                 memcpy(buf + desc_size, words, 32);
1771                 desc_size += 32;
1772             }
1773         }
1774     }
1775     return desc_size;
1776 }
1777 
1778 void css_do_schm(uint8_t mbk, int update, int dct, uint64_t mbo)
1779 {
1780     /* dct is currently ignored (not really meaningful for our devices) */
1781     /* TODO: Don't ignore mbk. */
1782     if (update && !channel_subsys.chnmon_active) {
1783         /* Enable measuring. */
1784         channel_subsys.chnmon_area = mbo;
1785         channel_subsys.chnmon_active = true;
1786     }
1787     if (!update && channel_subsys.chnmon_active) {
1788         /* Disable measuring. */
1789         channel_subsys.chnmon_area = 0;
1790         channel_subsys.chnmon_active = false;
1791     }
1792 }
1793 
1794 IOInstEnding css_do_rsch(SubchDev *sch)
1795 {
1796     SCHIB *schib = &sch->curr_status;
1797 
1798     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1799         return IOINST_CC_NOT_OPERATIONAL;
1800     }
1801 
1802     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1803         return IOINST_CC_STATUS_PRESENT;
1804     }
1805 
1806     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) != SCSW_FCTL_START_FUNC) ||
1807         (schib->scsw.ctrl & SCSW_ACTL_RESUME_PEND) ||
1808         (!(schib->scsw.ctrl & SCSW_ACTL_SUSP))) {
1809         return IOINST_CC_BUSY;
1810     }
1811 
1812     /* If monitoring is active, update counter. */
1813     if (channel_subsys.chnmon_active) {
1814         css_update_chnmon(sch);
1815     }
1816 
1817     schib->scsw.ctrl |= SCSW_ACTL_RESUME_PEND;
1818     return do_subchannel_work(sch);
1819 }
1820 
1821 int css_do_rchp(uint8_t cssid, uint8_t chpid)
1822 {
1823     uint8_t real_cssid;
1824 
1825     if (cssid > channel_subsys.max_cssid) {
1826         return -EINVAL;
1827     }
1828     if (channel_subsys.max_cssid == 0) {
1829         real_cssid = channel_subsys.default_cssid;
1830     } else {
1831         real_cssid = cssid;
1832     }
1833     if (!channel_subsys.css[real_cssid]) {
1834         return -EINVAL;
1835     }
1836 
1837     if (!channel_subsys.css[real_cssid]->chpids[chpid].in_use) {
1838         return -ENODEV;
1839     }
1840 
1841     if (!channel_subsys.css[real_cssid]->chpids[chpid].is_virtual) {
1842         fprintf(stderr,
1843                 "rchp unsupported for non-virtual chpid %x.%02x!\n",
1844                 real_cssid, chpid);
1845         return -ENODEV;
1846     }
1847 
1848     /* We don't really use a channel path, so we're done here. */
1849     css_queue_crw(CRW_RSC_CHP, CRW_ERC_INIT, 1,
1850                   channel_subsys.max_cssid > 0 ? 1 : 0, chpid);
1851     if (channel_subsys.max_cssid > 0) {
1852         css_queue_crw(CRW_RSC_CHP, CRW_ERC_INIT, 1, 0, real_cssid << 8);
1853     }
1854     return 0;
1855 }
1856 
1857 bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid)
1858 {
1859     SubchSet *set;
1860     uint8_t real_cssid;
1861 
1862     real_cssid = (!m && (cssid == 0)) ? channel_subsys.default_cssid : cssid;
1863     if (ssid > MAX_SSID ||
1864         !channel_subsys.css[real_cssid] ||
1865         !channel_subsys.css[real_cssid]->sch_set[ssid]) {
1866         return true;
1867     }
1868     set = channel_subsys.css[real_cssid]->sch_set[ssid];
1869     return schid > find_last_bit(set->schids_used,
1870                                  (MAX_SCHID + 1) / sizeof(unsigned long));
1871 }
1872 
1873 unsigned int css_find_free_chpid(uint8_t cssid)
1874 {
1875     CssImage *css = channel_subsys.css[cssid];
1876     unsigned int chpid;
1877 
1878     if (!css) {
1879         return MAX_CHPID + 1;
1880     }
1881 
1882     for (chpid = 0; chpid <= MAX_CHPID; chpid++) {
1883         /* skip reserved chpid */
1884         if (chpid == VIRTIO_CCW_CHPID) {
1885             continue;
1886         }
1887         if (!css->chpids[chpid].in_use) {
1888             return chpid;
1889         }
1890     }
1891     return MAX_CHPID + 1;
1892 }
1893 
1894 static int css_add_chpid(uint8_t cssid, uint8_t chpid, uint8_t type,
1895                          bool is_virt)
1896 {
1897     CssImage *css;
1898 
1899     trace_css_chpid_add(cssid, chpid, type);
1900     css = channel_subsys.css[cssid];
1901     if (!css) {
1902         return -EINVAL;
1903     }
1904     if (css->chpids[chpid].in_use) {
1905         return -EEXIST;
1906     }
1907     css->chpids[chpid].in_use = 1;
1908     css->chpids[chpid].type = type;
1909     css->chpids[chpid].is_virtual = is_virt;
1910 
1911     css_generate_chp_crws(cssid, chpid);
1912 
1913     return 0;
1914 }
1915 
1916 void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type)
1917 {
1918     SCHIB *schib = &sch->curr_status;
1919     int i;
1920     CssImage *css = channel_subsys.css[sch->cssid];
1921 
1922     assert(css != NULL);
1923     memset(&schib->pmcw, 0, sizeof(PMCW));
1924     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
1925     schib->pmcw.devno = sch->devno;
1926     /* single path */
1927     schib->pmcw.pim = 0x80;
1928     schib->pmcw.pom = 0xff;
1929     schib->pmcw.pam = 0x80;
1930     schib->pmcw.chpid[0] = chpid;
1931     if (!css->chpids[chpid].in_use) {
1932         css_add_chpid(sch->cssid, chpid, type, true);
1933     }
1934 
1935     memset(&schib->scsw, 0, sizeof(SCSW));
1936     schib->mba = 0;
1937     for (i = 0; i < ARRAY_SIZE(schib->mda); i++) {
1938         schib->mda[i] = 0;
1939     }
1940 }
1941 
1942 SubchDev *css_find_subch(uint8_t m, uint8_t cssid, uint8_t ssid, uint16_t schid)
1943 {
1944     uint8_t real_cssid;
1945 
1946     real_cssid = (!m && (cssid == 0)) ? channel_subsys.default_cssid : cssid;
1947 
1948     if (!channel_subsys.css[real_cssid]) {
1949         return NULL;
1950     }
1951 
1952     if (!channel_subsys.css[real_cssid]->sch_set[ssid]) {
1953         return NULL;
1954     }
1955 
1956     return channel_subsys.css[real_cssid]->sch_set[ssid]->sch[schid];
1957 }
1958 
1959 /**
1960  * Return free device number in subchannel set.
1961  *
1962  * Return index of the first free device number in the subchannel set
1963  * identified by @p cssid and @p ssid, beginning the search at @p
1964  * start and wrapping around at MAX_DEVNO. Return a value exceeding
1965  * MAX_SCHID if there are no free device numbers in the subchannel
1966  * set.
1967  */
1968 static uint32_t css_find_free_devno(uint8_t cssid, uint8_t ssid,
1969                                     uint16_t start)
1970 {
1971     uint32_t round;
1972 
1973     for (round = 0; round <= MAX_DEVNO; round++) {
1974         uint16_t devno = (start + round) % MAX_DEVNO;
1975 
1976         if (!css_devno_used(cssid, ssid, devno)) {
1977             return devno;
1978         }
1979     }
1980     return MAX_DEVNO + 1;
1981 }
1982 
1983 /**
1984  * Return first free subchannel (id) in subchannel set.
1985  *
1986  * Return index of the first free subchannel in the subchannel set
1987  * identified by @p cssid and @p ssid, if there is any. Return a value
1988  * exceeding MAX_SCHID if there are no free subchannels in the
1989  * subchannel set.
1990  */
1991 static uint32_t css_find_free_subch(uint8_t cssid, uint8_t ssid)
1992 {
1993     uint32_t schid;
1994 
1995     for (schid = 0; schid <= MAX_SCHID; schid++) {
1996         if (!css_find_subch(1, cssid, ssid, schid)) {
1997             return schid;
1998         }
1999     }
2000     return MAX_SCHID + 1;
2001 }
2002 
2003 /**
2004  * Return first free subchannel (id) in subchannel set for a device number
2005  *
2006  * Verify the device number @p devno is not used yet in the subchannel
2007  * set identified by @p cssid and @p ssid. Set @p schid to the index
2008  * of the first free subchannel in the subchannel set, if there is
2009  * any. Return true if everything succeeded and false otherwise.
2010  */
2011 static bool css_find_free_subch_for_devno(uint8_t cssid, uint8_t ssid,
2012                                           uint16_t devno, uint16_t *schid,
2013                                           Error **errp)
2014 {
2015     uint32_t free_schid;
2016 
2017     assert(schid);
2018     if (css_devno_used(cssid, ssid, devno)) {
2019         error_setg(errp, "Device %x.%x.%04x already exists",
2020                    cssid, ssid, devno);
2021         return false;
2022     }
2023     free_schid = css_find_free_subch(cssid, ssid);
2024     if (free_schid > MAX_SCHID) {
2025         error_setg(errp, "No free subchannel found for %x.%x.%04x",
2026                    cssid, ssid, devno);
2027         return false;
2028     }
2029     *schid = free_schid;
2030     return true;
2031 }
2032 
2033 /**
2034  * Return first free subchannel (id) and device number
2035  *
2036  * Locate the first free subchannel and first free device number in
2037  * any of the subchannel sets of the channel subsystem identified by
2038  * @p cssid. Return false if no free subchannel / device number could
2039  * be found. Otherwise set @p ssid, @p devno and @p schid to identify
2040  * the available subchannel and device number and return true.
2041  *
2042  * May modify @p ssid, @p devno and / or @p schid even if no free
2043  * subchannel / device number could be found.
2044  */
2045 static bool css_find_free_subch_and_devno(uint8_t cssid, uint8_t *ssid,
2046                                           uint16_t *devno, uint16_t *schid,
2047                                           Error **errp)
2048 {
2049     uint32_t free_schid, free_devno;
2050 
2051     assert(ssid && devno && schid);
2052     for (*ssid = 0; *ssid <= MAX_SSID; (*ssid)++) {
2053         free_schid = css_find_free_subch(cssid, *ssid);
2054         if (free_schid > MAX_SCHID) {
2055             continue;
2056         }
2057         free_devno = css_find_free_devno(cssid, *ssid, free_schid);
2058         if (free_devno > MAX_DEVNO) {
2059             continue;
2060         }
2061         *schid = free_schid;
2062         *devno = free_devno;
2063         return true;
2064     }
2065     error_setg(errp, "Virtual channel subsystem is full!");
2066     return false;
2067 }
2068 
2069 bool css_subch_visible(SubchDev *sch)
2070 {
2071     if (sch->ssid > channel_subsys.max_ssid) {
2072         return false;
2073     }
2074 
2075     if (sch->cssid != channel_subsys.default_cssid) {
2076         return (channel_subsys.max_cssid > 0);
2077     }
2078 
2079     return true;
2080 }
2081 
2082 bool css_present(uint8_t cssid)
2083 {
2084     return (channel_subsys.css[cssid] != NULL);
2085 }
2086 
2087 bool css_devno_used(uint8_t cssid, uint8_t ssid, uint16_t devno)
2088 {
2089     if (!channel_subsys.css[cssid]) {
2090         return false;
2091     }
2092     if (!channel_subsys.css[cssid]->sch_set[ssid]) {
2093         return false;
2094     }
2095 
2096     return !!test_bit(devno,
2097                       channel_subsys.css[cssid]->sch_set[ssid]->devnos_used);
2098 }
2099 
2100 void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,
2101                       uint16_t devno, SubchDev *sch)
2102 {
2103     CssImage *css;
2104     SubchSet *s_set;
2105 
2106     trace_css_assign_subch(sch ? "assign" : "deassign", cssid, ssid, schid,
2107                            devno);
2108     if (!channel_subsys.css[cssid]) {
2109         fprintf(stderr,
2110                 "Suspicious call to %s (%x.%x.%04x) for non-existing css!\n",
2111                 __func__, cssid, ssid, schid);
2112         return;
2113     }
2114     css = channel_subsys.css[cssid];
2115 
2116     if (!css->sch_set[ssid]) {
2117         css->sch_set[ssid] = g_new0(SubchSet, 1);
2118     }
2119     s_set = css->sch_set[ssid];
2120 
2121     s_set->sch[schid] = sch;
2122     if (sch) {
2123         set_bit(schid, s_set->schids_used);
2124         set_bit(devno, s_set->devnos_used);
2125     } else {
2126         clear_bit(schid, s_set->schids_used);
2127         clear_bit(devno, s_set->devnos_used);
2128     }
2129 }
2130 
2131 void css_queue_crw(uint8_t rsc, uint8_t erc, int solicited,
2132                    int chain, uint16_t rsid)
2133 {
2134     CrwContainer *crw_cont;
2135 
2136     trace_css_crw(rsc, erc, rsid, chain ? "(chained)" : "");
2137     /* TODO: Maybe use a static crw pool? */
2138     crw_cont = g_try_new0(CrwContainer, 1);
2139     if (!crw_cont) {
2140         channel_subsys.crws_lost = true;
2141         return;
2142     }
2143     crw_cont->crw.flags = (rsc << 8) | erc;
2144     if (solicited) {
2145         crw_cont->crw.flags |= CRW_FLAGS_MASK_S;
2146     }
2147     if (chain) {
2148         crw_cont->crw.flags |= CRW_FLAGS_MASK_C;
2149     }
2150     crw_cont->crw.rsid = rsid;
2151     if (channel_subsys.crws_lost) {
2152         crw_cont->crw.flags |= CRW_FLAGS_MASK_R;
2153         channel_subsys.crws_lost = false;
2154     }
2155 
2156     QTAILQ_INSERT_TAIL(&channel_subsys.pending_crws, crw_cont, sibling);
2157 
2158     if (channel_subsys.do_crw_mchk) {
2159         channel_subsys.do_crw_mchk = false;
2160         /* Inject crw pending machine check. */
2161         s390_crw_mchk();
2162     }
2163 }
2164 
2165 void css_generate_sch_crws(uint8_t cssid, uint8_t ssid, uint16_t schid,
2166                            int hotplugged, int add)
2167 {
2168     uint8_t guest_cssid;
2169     bool chain_crw;
2170 
2171     if (add && !hotplugged) {
2172         return;
2173     }
2174     if (channel_subsys.max_cssid == 0) {
2175         /* Default cssid shows up as 0. */
2176         guest_cssid = (cssid == channel_subsys.default_cssid) ? 0 : cssid;
2177     } else {
2178         /* Show real cssid to the guest. */
2179         guest_cssid = cssid;
2180     }
2181     /*
2182      * Only notify for higher subchannel sets/channel subsystems if the
2183      * guest has enabled it.
2184      */
2185     if ((ssid > channel_subsys.max_ssid) ||
2186         (guest_cssid > channel_subsys.max_cssid) ||
2187         ((channel_subsys.max_cssid == 0) &&
2188          (cssid != channel_subsys.default_cssid))) {
2189         return;
2190     }
2191     chain_crw = (channel_subsys.max_ssid > 0) ||
2192             (channel_subsys.max_cssid > 0);
2193     css_queue_crw(CRW_RSC_SUBCH, CRW_ERC_IPI, 0, chain_crw ? 1 : 0, schid);
2194     if (chain_crw) {
2195         css_queue_crw(CRW_RSC_SUBCH, CRW_ERC_IPI, 0, 0,
2196                       (guest_cssid << 8) | (ssid << 4));
2197     }
2198     /* RW_ERC_IPI --> clear pending interrupts */
2199     css_clear_io_interrupt(css_do_build_subchannel_id(cssid, ssid), schid);
2200 }
2201 
2202 void css_generate_chp_crws(uint8_t cssid, uint8_t chpid)
2203 {
2204     /* TODO */
2205 }
2206 
2207 void css_generate_css_crws(uint8_t cssid)
2208 {
2209     if (!channel_subsys.sei_pending) {
2210         css_queue_crw(CRW_RSC_CSS, CRW_ERC_EVENT, 0, 0, cssid);
2211     }
2212     channel_subsys.sei_pending = true;
2213 }
2214 
2215 void css_clear_sei_pending(void)
2216 {
2217     channel_subsys.sei_pending = false;
2218 }
2219 
2220 int css_enable_mcsse(void)
2221 {
2222     trace_css_enable_facility("mcsse");
2223     channel_subsys.max_cssid = MAX_CSSID;
2224     return 0;
2225 }
2226 
2227 int css_enable_mss(void)
2228 {
2229     trace_css_enable_facility("mss");
2230     channel_subsys.max_ssid = MAX_SSID;
2231     return 0;
2232 }
2233 
2234 void css_reset_sch(SubchDev *sch)
2235 {
2236     SCHIB *schib = &sch->curr_status;
2237 
2238     if ((schib->pmcw.flags & PMCW_FLAGS_MASK_ENA) != 0 && sch->disable_cb) {
2239         sch->disable_cb(sch);
2240     }
2241 
2242     schib->pmcw.intparm = 0;
2243     schib->pmcw.flags &= ~(PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
2244                   PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
2245                   PMCW_FLAGS_MASK_MP | PMCW_FLAGS_MASK_TF);
2246     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
2247     schib->pmcw.devno = sch->devno;
2248     schib->pmcw.pim = 0x80;
2249     schib->pmcw.lpm = schib->pmcw.pim;
2250     schib->pmcw.pnom = 0;
2251     schib->pmcw.lpum = 0;
2252     schib->pmcw.mbi = 0;
2253     schib->pmcw.pom = 0xff;
2254     schib->pmcw.pam = 0x80;
2255     schib->pmcw.chars &= ~(PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_XMWME |
2256                   PMCW_CHARS_MASK_CSENSE);
2257 
2258     memset(&schib->scsw, 0, sizeof(schib->scsw));
2259     schib->mba = 0;
2260 
2261     sch->channel_prog = 0x0;
2262     sch->last_cmd_valid = false;
2263     sch->thinint_active = false;
2264 }
2265 
2266 void css_reset(void)
2267 {
2268     CrwContainer *crw_cont;
2269 
2270     /* Clean up monitoring. */
2271     channel_subsys.chnmon_active = false;
2272     channel_subsys.chnmon_area = 0;
2273 
2274     /* Clear pending CRWs. */
2275     while ((crw_cont = QTAILQ_FIRST(&channel_subsys.pending_crws))) {
2276         QTAILQ_REMOVE(&channel_subsys.pending_crws, crw_cont, sibling);
2277         g_free(crw_cont);
2278     }
2279     channel_subsys.sei_pending = false;
2280     channel_subsys.do_crw_mchk = true;
2281     channel_subsys.crws_lost = false;
2282 
2283     /* Reset maximum ids. */
2284     channel_subsys.max_cssid = 0;
2285     channel_subsys.max_ssid = 0;
2286 }
2287 
2288 static void get_css_devid(Object *obj, Visitor *v, const char *name,
2289                           void *opaque, Error **errp)
2290 {
2291     DeviceState *dev = DEVICE(obj);
2292     Property *prop = opaque;
2293     CssDevId *dev_id = qdev_get_prop_ptr(dev, prop);
2294     char buffer[] = "xx.x.xxxx";
2295     char *p = buffer;
2296     int r;
2297 
2298     if (dev_id->valid) {
2299 
2300         r = snprintf(buffer, sizeof(buffer), "%02x.%1x.%04x", dev_id->cssid,
2301                      dev_id->ssid, dev_id->devid);
2302         assert(r == sizeof(buffer) - 1);
2303 
2304         /* drop leading zero */
2305         if (dev_id->cssid <= 0xf) {
2306             p++;
2307         }
2308     } else {
2309         snprintf(buffer, sizeof(buffer), "<unset>");
2310     }
2311 
2312     visit_type_str(v, name, &p, errp);
2313 }
2314 
2315 /*
2316  * parse <cssid>.<ssid>.<devid> and assert valid range for cssid/ssid
2317  */
2318 static void set_css_devid(Object *obj, Visitor *v, const char *name,
2319                           void *opaque, Error **errp)
2320 {
2321     DeviceState *dev = DEVICE(obj);
2322     Property *prop = opaque;
2323     CssDevId *dev_id = qdev_get_prop_ptr(dev, prop);
2324     Error *local_err = NULL;
2325     char *str;
2326     int num, n1, n2;
2327     unsigned int cssid, ssid, devid;
2328 
2329     if (dev->realized) {
2330         qdev_prop_set_after_realize(dev, name, errp);
2331         return;
2332     }
2333 
2334     visit_type_str(v, name, &str, &local_err);
2335     if (local_err) {
2336         error_propagate(errp, local_err);
2337         return;
2338     }
2339 
2340     num = sscanf(str, "%2x.%1x%n.%4x%n", &cssid, &ssid, &n1, &devid, &n2);
2341     if (num != 3 || (n2 - n1) != 5 || strlen(str) != n2) {
2342         error_set_from_qdev_prop_error(errp, EINVAL, dev, prop, str);
2343         goto out;
2344     }
2345     if ((cssid > MAX_CSSID) || (ssid > MAX_SSID)) {
2346         error_setg(errp, "Invalid cssid or ssid: cssid %x, ssid %x",
2347                    cssid, ssid);
2348         goto out;
2349     }
2350 
2351     dev_id->cssid = cssid;
2352     dev_id->ssid = ssid;
2353     dev_id->devid = devid;
2354     dev_id->valid = true;
2355 
2356 out:
2357     g_free(str);
2358 }
2359 
2360 const PropertyInfo css_devid_propinfo = {
2361     .name = "str",
2362     .description = "Identifier of an I/O device in the channel "
2363                    "subsystem, example: fe.1.23ab",
2364     .get = get_css_devid,
2365     .set = set_css_devid,
2366 };
2367 
2368 const PropertyInfo css_devid_ro_propinfo = {
2369     .name = "str",
2370     .description = "Read-only identifier of an I/O device in the channel "
2371                    "subsystem, example: fe.1.23ab",
2372     .get = get_css_devid,
2373 };
2374 
2375 SubchDev *css_create_sch(CssDevId bus_id, Error **errp)
2376 {
2377     uint16_t schid = 0;
2378     SubchDev *sch;
2379 
2380     if (bus_id.valid) {
2381         if (!channel_subsys.css[bus_id.cssid]) {
2382             css_create_css_image(bus_id.cssid, false);
2383         }
2384 
2385         if (!css_find_free_subch_for_devno(bus_id.cssid, bus_id.ssid,
2386                                            bus_id.devid, &schid, errp)) {
2387             return NULL;
2388         }
2389     } else {
2390         for (bus_id.cssid = channel_subsys.default_cssid;;) {
2391             if (!channel_subsys.css[bus_id.cssid]) {
2392                 css_create_css_image(bus_id.cssid, false);
2393             }
2394 
2395             if   (css_find_free_subch_and_devno(bus_id.cssid, &bus_id.ssid,
2396                                                 &bus_id.devid, &schid,
2397                                                 NULL)) {
2398                 break;
2399             }
2400             bus_id.cssid = (bus_id.cssid + 1) % MAX_CSSID;
2401             if (bus_id.cssid == channel_subsys.default_cssid) {
2402                 error_setg(errp, "Virtual channel subsystem is full!");
2403                 return NULL;
2404             }
2405         }
2406     }
2407 
2408     sch = g_new0(SubchDev, 1);
2409     sch->cssid = bus_id.cssid;
2410     sch->ssid = bus_id.ssid;
2411     sch->devno = bus_id.devid;
2412     sch->schid = schid;
2413     css_subch_assign(sch->cssid, sch->ssid, schid, sch->devno, sch);
2414     return sch;
2415 }
2416 
2417 static int css_sch_get_chpids(SubchDev *sch, CssDevId *dev_id)
2418 {
2419     char *fid_path;
2420     FILE *fd;
2421     uint32_t chpid[8];
2422     int i;
2423     SCHIB *schib = &sch->curr_status;
2424 
2425     fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/chpids",
2426                                dev_id->cssid, dev_id->ssid, dev_id->devid);
2427     fd = fopen(fid_path, "r");
2428     if (fd == NULL) {
2429         error_report("%s: open %s failed", __func__, fid_path);
2430         g_free(fid_path);
2431         return -EINVAL;
2432     }
2433 
2434     if (fscanf(fd, "%x %x %x %x %x %x %x %x",
2435         &chpid[0], &chpid[1], &chpid[2], &chpid[3],
2436         &chpid[4], &chpid[5], &chpid[6], &chpid[7]) != 8) {
2437         fclose(fd);
2438         g_free(fid_path);
2439         return -EINVAL;
2440     }
2441 
2442     for (i = 0; i < ARRAY_SIZE(schib->pmcw.chpid); i++) {
2443         schib->pmcw.chpid[i] = chpid[i];
2444     }
2445 
2446     fclose(fd);
2447     g_free(fid_path);
2448 
2449     return 0;
2450 }
2451 
2452 static int css_sch_get_path_masks(SubchDev *sch, CssDevId *dev_id)
2453 {
2454     char *fid_path;
2455     FILE *fd;
2456     uint32_t pim, pam, pom;
2457     SCHIB *schib = &sch->curr_status;
2458 
2459     fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/pimpampom",
2460                                dev_id->cssid, dev_id->ssid, dev_id->devid);
2461     fd = fopen(fid_path, "r");
2462     if (fd == NULL) {
2463         error_report("%s: open %s failed", __func__, fid_path);
2464         g_free(fid_path);
2465         return -EINVAL;
2466     }
2467 
2468     if (fscanf(fd, "%x %x %x", &pim, &pam, &pom) != 3) {
2469         fclose(fd);
2470         g_free(fid_path);
2471         return -EINVAL;
2472     }
2473 
2474     schib->pmcw.pim = pim;
2475     schib->pmcw.pam = pam;
2476     schib->pmcw.pom = pom;
2477     fclose(fd);
2478     g_free(fid_path);
2479 
2480     return 0;
2481 }
2482 
2483 static int css_sch_get_chpid_type(uint8_t chpid, uint32_t *type,
2484                                   CssDevId *dev_id)
2485 {
2486     char *fid_path;
2487     FILE *fd;
2488 
2489     fid_path = g_strdup_printf("/sys/devices/css%x/chp0.%02x/type",
2490                                dev_id->cssid, chpid);
2491     fd = fopen(fid_path, "r");
2492     if (fd == NULL) {
2493         error_report("%s: open %s failed", __func__, fid_path);
2494         g_free(fid_path);
2495         return -EINVAL;
2496     }
2497 
2498     if (fscanf(fd, "%x", type) != 1) {
2499         fclose(fd);
2500         g_free(fid_path);
2501         return -EINVAL;
2502     }
2503 
2504     fclose(fd);
2505     g_free(fid_path);
2506 
2507     return 0;
2508 }
2509 
2510 /*
2511  * We currently retrieve the real device information from sysfs to build the
2512  * guest subchannel information block without considering the migration feature.
2513  * We need to revisit this problem when we want to add migration support.
2514  */
2515 int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id)
2516 {
2517     CssImage *css = channel_subsys.css[sch->cssid];
2518     SCHIB *schib = &sch->curr_status;
2519     uint32_t type;
2520     int i, ret;
2521 
2522     assert(css != NULL);
2523     memset(&schib->pmcw, 0, sizeof(PMCW));
2524     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
2525     /* We are dealing with I/O subchannels only. */
2526     schib->pmcw.devno = sch->devno;
2527 
2528     /* Grab path mask from sysfs. */
2529     ret = css_sch_get_path_masks(sch, dev_id);
2530     if (ret) {
2531         return ret;
2532     }
2533 
2534     /* Grab chpids from sysfs. */
2535     ret = css_sch_get_chpids(sch, dev_id);
2536     if (ret) {
2537         return ret;
2538     }
2539 
2540    /* Build chpid type. */
2541     for (i = 0; i < ARRAY_SIZE(schib->pmcw.chpid); i++) {
2542         if (schib->pmcw.chpid[i] && !css->chpids[schib->pmcw.chpid[i]].in_use) {
2543             ret = css_sch_get_chpid_type(schib->pmcw.chpid[i], &type, dev_id);
2544             if (ret) {
2545                 return ret;
2546             }
2547             css_add_chpid(sch->cssid, schib->pmcw.chpid[i], type, false);
2548         }
2549     }
2550 
2551     memset(&schib->scsw, 0, sizeof(SCSW));
2552     schib->mba = 0;
2553     for (i = 0; i < ARRAY_SIZE(schib->mda); i++) {
2554         schib->mda[i] = 0;
2555     }
2556 
2557     return 0;
2558 }
2559