xref: /openbmc/qemu/hw/s390x/css.c (revision 49d755d0)
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     if (!cds->do_skip) {
834         ret = address_space_rw(&address_space_memory, cds->cda,
835                                MEMTXATTRS_UNSPECIFIED, buff, len, op);
836     } else {
837         ret = MEMTX_OK;
838     }
839     if (ret != MEMTX_OK) {
840         cds->flags |= CDS_F_STREAM_BROKEN;
841         return -EINVAL;
842     }
843 incr:
844     cds->at_byte += len;
845     cds->cda += len;
846     return 0;
847 }
848 
849 /* returns values between 1 and bsz, where bsz is a power of 2 */
850 static inline uint16_t ida_continuous_left(hwaddr cda, uint64_t bsz)
851 {
852     return bsz - (cda & (bsz - 1));
853 }
854 
855 static inline uint64_t ccw_ida_block_size(uint8_t flags)
856 {
857     if ((flags & CDS_F_C64) && !(flags & CDS_F_I2K)) {
858         return 1ULL << 12;
859     }
860     return 1ULL << 11;
861 }
862 
863 static inline int ida_read_next_idaw(CcwDataStream *cds)
864 {
865     union {uint64_t fmt2; uint32_t fmt1; } idaw;
866     int ret;
867     hwaddr idaw_addr;
868     bool idaw_fmt2 = cds->flags & CDS_F_C64;
869     bool ccw_fmt1 = cds->flags & CDS_F_FMT;
870 
871     if (idaw_fmt2) {
872         idaw_addr = cds->cda_orig + sizeof(idaw.fmt2) * cds->at_idaw;
873         if (idaw_addr & 0x07 || !cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
874             return -EINVAL; /* channel program check */
875         }
876         ret = address_space_rw(&address_space_memory, idaw_addr,
877                                MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt2,
878                                sizeof(idaw.fmt2), false);
879         cds->cda = be64_to_cpu(idaw.fmt2);
880     } else {
881         idaw_addr = cds->cda_orig + sizeof(idaw.fmt1) * cds->at_idaw;
882         if (idaw_addr & 0x03 || !cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
883             return -EINVAL; /* channel program check */
884         }
885         ret = address_space_rw(&address_space_memory, idaw_addr,
886                                MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt1,
887                                sizeof(idaw.fmt1), false);
888         cds->cda = be64_to_cpu(idaw.fmt1);
889         if (cds->cda & 0x80000000) {
890             return -EINVAL; /* channel program check */
891         }
892     }
893     ++(cds->at_idaw);
894     if (ret != MEMTX_OK) {
895         /* assume inaccessible address */
896         return -EINVAL; /* channel program check */
897     }
898     return 0;
899 }
900 
901 static int ccw_dstream_rw_ida(CcwDataStream *cds, void *buff, int len,
902                               CcwDataStreamOp op)
903 {
904     uint64_t bsz = ccw_ida_block_size(cds->flags);
905     int ret = 0;
906     uint16_t cont_left, iter_len;
907 
908     ret = cds_check_len(cds, len);
909     if (ret <= 0) {
910         return ret;
911     }
912     if (!cds->at_idaw) {
913         /* read first idaw */
914         ret = ida_read_next_idaw(cds);
915         if (ret) {
916             goto err;
917         }
918         cont_left = ida_continuous_left(cds->cda, bsz);
919     } else {
920         cont_left = ida_continuous_left(cds->cda, bsz);
921         if (cont_left == bsz) {
922             ret = ida_read_next_idaw(cds);
923             if (ret) {
924                 goto err;
925             }
926             if (cds->cda & (bsz - 1)) {
927                 ret = -EINVAL; /* channel program check */
928                 goto err;
929             }
930         }
931     }
932     do {
933         iter_len = MIN(len, cont_left);
934         if (op != CDS_OP_A) {
935             if (!cds->do_skip) {
936                 ret = address_space_rw(&address_space_memory, cds->cda,
937                                        MEMTXATTRS_UNSPECIFIED, buff, iter_len,
938                                        op);
939             } else {
940                 ret = MEMTX_OK;
941             }
942             if (ret != MEMTX_OK) {
943                 /* assume inaccessible address */
944                 ret = -EINVAL; /* channel program check */
945                 goto err;
946             }
947         }
948         cds->at_byte += iter_len;
949         cds->cda += iter_len;
950         len -= iter_len;
951         if (!len) {
952             break;
953         }
954         ret = ida_read_next_idaw(cds);
955         if (ret) {
956             goto err;
957         }
958         cont_left = bsz;
959     } while (true);
960     return ret;
961 err:
962     cds->flags |= CDS_F_STREAM_BROKEN;
963     return ret;
964 }
965 
966 void ccw_dstream_init(CcwDataStream *cds, CCW1 const *ccw, ORB const *orb)
967 {
968     /*
969      * We don't support MIDA (an optional facility) yet and we
970      * catch this earlier. Just for expressing the precondition.
971      */
972     g_assert(!(orb->ctrl1 & ORB_CTRL1_MASK_MIDAW));
973     cds->flags = (orb->ctrl0 & ORB_CTRL0_MASK_I2K ? CDS_F_I2K : 0) |
974                  (orb->ctrl0 & ORB_CTRL0_MASK_C64 ? CDS_F_C64 : 0) |
975                  (orb->ctrl0 & ORB_CTRL0_MASK_FMT ? CDS_F_FMT : 0) |
976                  (ccw->flags & CCW_FLAG_IDA ? CDS_F_IDA : 0);
977 
978     cds->count = ccw->count;
979     cds->cda_orig = ccw->cda;
980     /* skip is only effective for read, read backwards, or sense commands */
981     cds->do_skip = (ccw->flags & CCW_FLAG_SKIP) &&
982         ((ccw->cmd_code & 0x0f) == CCW_CMD_BASIC_SENSE ||
983          (ccw->cmd_code & 0x03) == 0x02 /* read */ ||
984          (ccw->cmd_code & 0x0f) == 0x0c /* read backwards */);
985     ccw_dstream_rewind(cds);
986     if (!(cds->flags & CDS_F_IDA)) {
987         cds->op_handler = ccw_dstream_rw_noflags;
988     } else {
989         cds->op_handler = ccw_dstream_rw_ida;
990     }
991 }
992 
993 static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
994                              bool suspend_allowed)
995 {
996     int ret;
997     bool check_len;
998     int len;
999     CCW1 ccw;
1000 
1001     if (!ccw_addr) {
1002         return -EINVAL; /* channel-program check */
1003     }
1004     /* Check doubleword aligned and 31 or 24 (fmt 0) bit addressable. */
1005     if (ccw_addr & (sch->ccw_fmt_1 ? 0x80000007 : 0xff000007)) {
1006         return -EINVAL;
1007     }
1008 
1009     /* Translate everything to format-1 ccws - the information is the same. */
1010     ccw = copy_ccw_from_guest(ccw_addr, sch->ccw_fmt_1);
1011 
1012     /* Check for invalid command codes. */
1013     if ((ccw.cmd_code & 0x0f) == 0) {
1014         return -EINVAL;
1015     }
1016     if (((ccw.cmd_code & 0x0f) == CCW_CMD_TIC) &&
1017         ((ccw.cmd_code & 0xf0) != 0)) {
1018         return -EINVAL;
1019     }
1020     if (!sch->ccw_fmt_1 && (ccw.count == 0) &&
1021         (ccw.cmd_code != CCW_CMD_TIC)) {
1022         return -EINVAL;
1023     }
1024 
1025     /* We don't support MIDA. */
1026     if (ccw.flags & CCW_FLAG_MIDA) {
1027         return -EINVAL;
1028     }
1029 
1030     if (ccw.flags & CCW_FLAG_SUSPEND) {
1031         return suspend_allowed ? -EINPROGRESS : -EINVAL;
1032     }
1033 
1034     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
1035 
1036     if (!ccw.cda) {
1037         if (sch->ccw_no_data_cnt == 255) {
1038             return -EINVAL;
1039         }
1040         sch->ccw_no_data_cnt++;
1041     }
1042 
1043     /* Look at the command. */
1044     ccw_dstream_init(&sch->cds, &ccw, &(sch->orb));
1045     switch (ccw.cmd_code) {
1046     case CCW_CMD_NOOP:
1047         /* Nothing to do. */
1048         ret = 0;
1049         break;
1050     case CCW_CMD_BASIC_SENSE:
1051         if (check_len) {
1052             if (ccw.count != sizeof(sch->sense_data)) {
1053                 ret = -EINVAL;
1054                 break;
1055             }
1056         }
1057         len = MIN(ccw.count, sizeof(sch->sense_data));
1058         ccw_dstream_write_buf(&sch->cds, sch->sense_data, len);
1059         sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
1060         memset(sch->sense_data, 0, sizeof(sch->sense_data));
1061         ret = 0;
1062         break;
1063     case CCW_CMD_SENSE_ID:
1064     {
1065         /* According to SA22-7204-01, Sense-ID can store up to 256 bytes */
1066         uint8_t sense_id[256];
1067 
1068         copy_sense_id_to_guest(sense_id, &sch->id);
1069         /* Sense ID information is device specific. */
1070         if (check_len) {
1071             if (ccw.count != sizeof(sense_id)) {
1072                 ret = -EINVAL;
1073                 break;
1074             }
1075         }
1076         len = MIN(ccw.count, sizeof(sense_id));
1077         /*
1078          * Only indicate 0xff in the first sense byte if we actually
1079          * have enough place to store at least bytes 0-3.
1080          */
1081         if (len >= 4) {
1082             sense_id[0] = 0xff;
1083         } else {
1084             sense_id[0] = 0;
1085         }
1086         ccw_dstream_write_buf(&sch->cds, sense_id, len);
1087         sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
1088         ret = 0;
1089         break;
1090     }
1091     case CCW_CMD_TIC:
1092         if (sch->last_cmd_valid && (sch->last_cmd.cmd_code == CCW_CMD_TIC)) {
1093             ret = -EINVAL;
1094             break;
1095         }
1096         if (ccw.flags || ccw.count) {
1097             /* We have already sanitized these if converted from fmt 0. */
1098             ret = -EINVAL;
1099             break;
1100         }
1101         sch->channel_prog = ccw.cda;
1102         ret = -EAGAIN;
1103         break;
1104     default:
1105         if (sch->ccw_cb) {
1106             /* Handle device specific commands. */
1107             ret = sch->ccw_cb(sch, ccw);
1108         } else {
1109             ret = -ENOSYS;
1110         }
1111         break;
1112     }
1113     sch->last_cmd = ccw;
1114     sch->last_cmd_valid = true;
1115     if (ret == 0) {
1116         if (ccw.flags & CCW_FLAG_CC) {
1117             sch->channel_prog += 8;
1118             ret = -EAGAIN;
1119         }
1120     }
1121 
1122     return ret;
1123 }
1124 
1125 static void sch_handle_start_func_virtual(SubchDev *sch)
1126 {
1127     SCHIB *schib = &sch->curr_status;
1128     int path;
1129     int ret;
1130     bool suspend_allowed;
1131 
1132     /* Path management: In our simple css, we always choose the only path. */
1133     path = 0x80;
1134 
1135     if (!(schib->scsw.ctrl & SCSW_ACTL_SUSP)) {
1136         /* Start Function triggered via ssch, i.e. we have an ORB */
1137         ORB *orb = &sch->orb;
1138         schib->scsw.cstat = 0;
1139         schib->scsw.dstat = 0;
1140         /* Look at the orb and try to execute the channel program. */
1141         schib->pmcw.intparm = orb->intparm;
1142         if (!(orb->lpm & path)) {
1143             /* Generate a deferred cc 3 condition. */
1144             schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
1145             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1146             schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
1147             return;
1148         }
1149         sch->ccw_fmt_1 = !!(orb->ctrl0 & ORB_CTRL0_MASK_FMT);
1150         schib->scsw.flags |= (sch->ccw_fmt_1) ? SCSW_FLAGS_MASK_FMT : 0;
1151         sch->ccw_no_data_cnt = 0;
1152         suspend_allowed = !!(orb->ctrl0 & ORB_CTRL0_MASK_SPND);
1153     } else {
1154         /* Start Function resumed via rsch */
1155         schib->scsw.ctrl &= ~(SCSW_ACTL_SUSP | SCSW_ACTL_RESUME_PEND);
1156         /* The channel program had been suspended before. */
1157         suspend_allowed = true;
1158     }
1159     sch->last_cmd_valid = false;
1160     do {
1161         ret = css_interpret_ccw(sch, sch->channel_prog, suspend_allowed);
1162         switch (ret) {
1163         case -EAGAIN:
1164             /* ccw chain, continue processing */
1165             break;
1166         case 0:
1167             /* success */
1168             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1169             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1170             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
1171                     SCSW_STCTL_STATUS_PEND;
1172             schib->scsw.dstat = SCSW_DSTAT_CHANNEL_END | SCSW_DSTAT_DEVICE_END;
1173             schib->scsw.cpa = sch->channel_prog + 8;
1174             break;
1175         case -EIO:
1176             /* I/O errors, status depends on specific devices */
1177             break;
1178         case -ENOSYS:
1179             /* unsupported command, generate unit check (command reject) */
1180             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1181             schib->scsw.dstat = SCSW_DSTAT_UNIT_CHECK;
1182             /* Set sense bit 0 in ecw0. */
1183             sch->sense_data[0] = 0x80;
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         case -EINPROGRESS:
1190             /* channel program has been suspended */
1191             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1192             schib->scsw.ctrl |= SCSW_ACTL_SUSP;
1193             break;
1194         default:
1195             /* error, generate channel program check */
1196             schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
1197             schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
1198             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1199             schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
1200                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
1201             schib->scsw.cpa = sch->channel_prog + 8;
1202             break;
1203         }
1204     } while (ret == -EAGAIN);
1205 
1206 }
1207 
1208 static IOInstEnding sch_handle_start_func_passthrough(SubchDev *sch)
1209 {
1210     SCHIB *schib = &sch->curr_status;
1211     ORB *orb = &sch->orb;
1212     if (!(schib->scsw.ctrl & SCSW_ACTL_SUSP)) {
1213         assert(orb != NULL);
1214         schib->pmcw.intparm = orb->intparm;
1215     }
1216     return s390_ccw_cmd_request(sch);
1217 }
1218 
1219 /*
1220  * On real machines, this would run asynchronously to the main vcpus.
1221  * We might want to make some parts of the ssch handling (interpreting
1222  * read/writes) asynchronous later on if we start supporting more than
1223  * our current very simple devices.
1224  */
1225 IOInstEnding do_subchannel_work_virtual(SubchDev *sch)
1226 {
1227     SCHIB *schib = &sch->curr_status;
1228 
1229     if (schib->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {
1230         sch_handle_clear_func(sch);
1231     } else if (schib->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {
1232         sch_handle_halt_func(sch);
1233     } else if (schib->scsw.ctrl & SCSW_FCTL_START_FUNC) {
1234         /* Triggered by both ssch and rsch. */
1235         sch_handle_start_func_virtual(sch);
1236     }
1237     css_inject_io_interrupt(sch);
1238     /* inst must succeed if this func is called */
1239     return IOINST_CC_EXPECTED;
1240 }
1241 
1242 IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
1243 {
1244     SCHIB *schib = &sch->curr_status;
1245 
1246     if (schib->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {
1247         /* TODO: Clear handling */
1248         sch_handle_clear_func(sch);
1249     } else if (schib->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {
1250         /* TODO: Halt handling */
1251         sch_handle_halt_func(sch);
1252     } else if (schib->scsw.ctrl & SCSW_FCTL_START_FUNC) {
1253         return sch_handle_start_func_passthrough(sch);
1254     }
1255     return IOINST_CC_EXPECTED;
1256 }
1257 
1258 static IOInstEnding do_subchannel_work(SubchDev *sch)
1259 {
1260     if (!sch->do_subchannel_work) {
1261         return IOINST_CC_STATUS_PRESENT;
1262     }
1263     g_assert(sch->curr_status.scsw.ctrl & SCSW_CTRL_MASK_FCTL);
1264     return sch->do_subchannel_work(sch);
1265 }
1266 
1267 static void copy_pmcw_to_guest(PMCW *dest, const PMCW *src)
1268 {
1269     int i;
1270 
1271     dest->intparm = cpu_to_be32(src->intparm);
1272     dest->flags = cpu_to_be16(src->flags);
1273     dest->devno = cpu_to_be16(src->devno);
1274     dest->lpm = src->lpm;
1275     dest->pnom = src->pnom;
1276     dest->lpum = src->lpum;
1277     dest->pim = src->pim;
1278     dest->mbi = cpu_to_be16(src->mbi);
1279     dest->pom = src->pom;
1280     dest->pam = src->pam;
1281     for (i = 0; i < ARRAY_SIZE(dest->chpid); i++) {
1282         dest->chpid[i] = src->chpid[i];
1283     }
1284     dest->chars = cpu_to_be32(src->chars);
1285 }
1286 
1287 void copy_scsw_to_guest(SCSW *dest, const SCSW *src)
1288 {
1289     dest->flags = cpu_to_be16(src->flags);
1290     dest->ctrl = cpu_to_be16(src->ctrl);
1291     dest->cpa = cpu_to_be32(src->cpa);
1292     dest->dstat = src->dstat;
1293     dest->cstat = src->cstat;
1294     dest->count = cpu_to_be16(src->count);
1295 }
1296 
1297 static void copy_schib_to_guest(SCHIB *dest, const SCHIB *src)
1298 {
1299     int i;
1300     /*
1301      * We copy the PMCW and SCSW in and out of local variables to
1302      * avoid taking the address of members of a packed struct.
1303      */
1304     PMCW src_pmcw, dest_pmcw;
1305     SCSW src_scsw, dest_scsw;
1306 
1307     src_pmcw = src->pmcw;
1308     copy_pmcw_to_guest(&dest_pmcw, &src_pmcw);
1309     dest->pmcw = dest_pmcw;
1310     src_scsw = src->scsw;
1311     copy_scsw_to_guest(&dest_scsw, &src_scsw);
1312     dest->scsw = dest_scsw;
1313     dest->mba = cpu_to_be64(src->mba);
1314     for (i = 0; i < ARRAY_SIZE(dest->mda); i++) {
1315         dest->mda[i] = src->mda[i];
1316     }
1317 }
1318 
1319 int css_do_stsch(SubchDev *sch, SCHIB *schib)
1320 {
1321     /* Use current status. */
1322     copy_schib_to_guest(schib, &sch->curr_status);
1323     return 0;
1324 }
1325 
1326 static void copy_pmcw_from_guest(PMCW *dest, const PMCW *src)
1327 {
1328     int i;
1329 
1330     dest->intparm = be32_to_cpu(src->intparm);
1331     dest->flags = be16_to_cpu(src->flags);
1332     dest->devno = be16_to_cpu(src->devno);
1333     dest->lpm = src->lpm;
1334     dest->pnom = src->pnom;
1335     dest->lpum = src->lpum;
1336     dest->pim = src->pim;
1337     dest->mbi = be16_to_cpu(src->mbi);
1338     dest->pom = src->pom;
1339     dest->pam = src->pam;
1340     for (i = 0; i < ARRAY_SIZE(dest->chpid); i++) {
1341         dest->chpid[i] = src->chpid[i];
1342     }
1343     dest->chars = be32_to_cpu(src->chars);
1344 }
1345 
1346 static void copy_scsw_from_guest(SCSW *dest, const SCSW *src)
1347 {
1348     dest->flags = be16_to_cpu(src->flags);
1349     dest->ctrl = be16_to_cpu(src->ctrl);
1350     dest->cpa = be32_to_cpu(src->cpa);
1351     dest->dstat = src->dstat;
1352     dest->cstat = src->cstat;
1353     dest->count = be16_to_cpu(src->count);
1354 }
1355 
1356 static void copy_schib_from_guest(SCHIB *dest, const SCHIB *src)
1357 {
1358     int i;
1359     /*
1360      * We copy the PMCW and SCSW in and out of local variables to
1361      * avoid taking the address of members of a packed struct.
1362      */
1363     PMCW src_pmcw, dest_pmcw;
1364     SCSW src_scsw, dest_scsw;
1365 
1366     src_pmcw = src->pmcw;
1367     copy_pmcw_from_guest(&dest_pmcw, &src_pmcw);
1368     dest->pmcw = dest_pmcw;
1369     src_scsw = src->scsw;
1370     copy_scsw_from_guest(&dest_scsw, &src_scsw);
1371     dest->scsw = dest_scsw;
1372     dest->mba = be64_to_cpu(src->mba);
1373     for (i = 0; i < ARRAY_SIZE(dest->mda); i++) {
1374         dest->mda[i] = src->mda[i];
1375     }
1376 }
1377 
1378 IOInstEnding css_do_msch(SubchDev *sch, const SCHIB *orig_schib)
1379 {
1380     SCHIB *schib = &sch->curr_status;
1381     uint16_t oldflags;
1382     SCHIB schib_copy;
1383 
1384     if (!(schib->pmcw.flags & PMCW_FLAGS_MASK_DNV)) {
1385         return IOINST_CC_EXPECTED;
1386     }
1387 
1388     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1389         return IOINST_CC_STATUS_PRESENT;
1390     }
1391 
1392     if (schib->scsw.ctrl &
1393         (SCSW_FCTL_START_FUNC|SCSW_FCTL_HALT_FUNC|SCSW_FCTL_CLEAR_FUNC)) {
1394         return IOINST_CC_BUSY;
1395     }
1396 
1397     copy_schib_from_guest(&schib_copy, orig_schib);
1398     /* Only update the program-modifiable fields. */
1399     schib->pmcw.intparm = schib_copy.pmcw.intparm;
1400     oldflags = schib->pmcw.flags;
1401     schib->pmcw.flags &= ~(PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
1402                   PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
1403                   PMCW_FLAGS_MASK_MP);
1404     schib->pmcw.flags |= schib_copy.pmcw.flags &
1405             (PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
1406              PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
1407              PMCW_FLAGS_MASK_MP);
1408     schib->pmcw.lpm = schib_copy.pmcw.lpm;
1409     schib->pmcw.mbi = schib_copy.pmcw.mbi;
1410     schib->pmcw.pom = schib_copy.pmcw.pom;
1411     schib->pmcw.chars &= ~(PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_CSENSE);
1412     schib->pmcw.chars |= schib_copy.pmcw.chars &
1413             (PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_CSENSE);
1414     schib->mba = schib_copy.mba;
1415 
1416     /* Has the channel been disabled? */
1417     if (sch->disable_cb && (oldflags & PMCW_FLAGS_MASK_ENA) != 0
1418         && (schib->pmcw.flags & PMCW_FLAGS_MASK_ENA) == 0) {
1419         sch->disable_cb(sch);
1420     }
1421     return IOINST_CC_EXPECTED;
1422 }
1423 
1424 IOInstEnding css_do_xsch(SubchDev *sch)
1425 {
1426     SCHIB *schib = &sch->curr_status;
1427 
1428     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1429         return IOINST_CC_NOT_OPERATIONAL;
1430     }
1431 
1432     if (schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) {
1433         return IOINST_CC_STATUS_PRESENT;
1434     }
1435 
1436     if (!(schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) ||
1437         ((schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) != SCSW_FCTL_START_FUNC) ||
1438         (!(schib->scsw.ctrl &
1439            (SCSW_ACTL_RESUME_PEND | SCSW_ACTL_START_PEND | SCSW_ACTL_SUSP))) ||
1440         (schib->scsw.ctrl & SCSW_ACTL_SUBCH_ACTIVE)) {
1441         return IOINST_CC_BUSY;
1442     }
1443 
1444     /* Cancel the current operation. */
1445     schib->scsw.ctrl &= ~(SCSW_FCTL_START_FUNC |
1446                  SCSW_ACTL_RESUME_PEND |
1447                  SCSW_ACTL_START_PEND |
1448                  SCSW_ACTL_SUSP);
1449     sch->channel_prog = 0x0;
1450     sch->last_cmd_valid = false;
1451     schib->scsw.dstat = 0;
1452     schib->scsw.cstat = 0;
1453     return IOINST_CC_EXPECTED;
1454 }
1455 
1456 IOInstEnding css_do_csch(SubchDev *sch)
1457 {
1458     SCHIB *schib = &sch->curr_status;
1459 
1460     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1461         return IOINST_CC_NOT_OPERATIONAL;
1462     }
1463 
1464     /* Trigger the clear function. */
1465     schib->scsw.ctrl &= ~(SCSW_CTRL_MASK_FCTL | SCSW_CTRL_MASK_ACTL);
1466     schib->scsw.ctrl |= SCSW_FCTL_CLEAR_FUNC | SCSW_ACTL_CLEAR_PEND;
1467 
1468     return do_subchannel_work(sch);
1469 }
1470 
1471 IOInstEnding css_do_hsch(SubchDev *sch)
1472 {
1473     SCHIB *schib = &sch->curr_status;
1474 
1475     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1476         return IOINST_CC_NOT_OPERATIONAL;
1477     }
1478 
1479     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) == SCSW_STCTL_STATUS_PEND) ||
1480         (schib->scsw.ctrl & (SCSW_STCTL_PRIMARY |
1481                     SCSW_STCTL_SECONDARY |
1482                     SCSW_STCTL_ALERT))) {
1483         return IOINST_CC_STATUS_PRESENT;
1484     }
1485 
1486     if (schib->scsw.ctrl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
1487         return IOINST_CC_BUSY;
1488     }
1489 
1490     /* Trigger the halt function. */
1491     schib->scsw.ctrl |= SCSW_FCTL_HALT_FUNC;
1492     schib->scsw.ctrl &= ~SCSW_FCTL_START_FUNC;
1493     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_ACTL) ==
1494          (SCSW_ACTL_SUBCH_ACTIVE | SCSW_ACTL_DEVICE_ACTIVE)) &&
1495         ((schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL) ==
1496          SCSW_STCTL_INTERMEDIATE)) {
1497         schib->scsw.ctrl &= ~SCSW_STCTL_STATUS_PEND;
1498     }
1499     schib->scsw.ctrl |= SCSW_ACTL_HALT_PEND;
1500 
1501     return do_subchannel_work(sch);
1502 }
1503 
1504 static void css_update_chnmon(SubchDev *sch)
1505 {
1506     if (!(sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_MME)) {
1507         /* Not active. */
1508         return;
1509     }
1510     /* The counter is conveniently located at the beginning of the struct. */
1511     if (sch->curr_status.pmcw.chars & PMCW_CHARS_MASK_MBFC) {
1512         /* Format 1, per-subchannel area. */
1513         uint32_t count;
1514 
1515         count = address_space_ldl(&address_space_memory,
1516                                   sch->curr_status.mba,
1517                                   MEMTXATTRS_UNSPECIFIED,
1518                                   NULL);
1519         count++;
1520         address_space_stl(&address_space_memory, sch->curr_status.mba, count,
1521                           MEMTXATTRS_UNSPECIFIED, NULL);
1522     } else {
1523         /* Format 0, global area. */
1524         uint32_t offset;
1525         uint16_t count;
1526 
1527         offset = sch->curr_status.pmcw.mbi << 5;
1528         count = address_space_lduw(&address_space_memory,
1529                                    channel_subsys.chnmon_area + offset,
1530                                    MEMTXATTRS_UNSPECIFIED,
1531                                    NULL);
1532         count++;
1533         address_space_stw(&address_space_memory,
1534                           channel_subsys.chnmon_area + offset, count,
1535                           MEMTXATTRS_UNSPECIFIED, NULL);
1536     }
1537 }
1538 
1539 IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb)
1540 {
1541     SCHIB *schib = &sch->curr_status;
1542 
1543     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1544         return IOINST_CC_NOT_OPERATIONAL;
1545     }
1546 
1547     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1548         return IOINST_CC_STATUS_PRESENT;
1549     }
1550 
1551     if (schib->scsw.ctrl & (SCSW_FCTL_START_FUNC |
1552                    SCSW_FCTL_HALT_FUNC |
1553                    SCSW_FCTL_CLEAR_FUNC)) {
1554         return IOINST_CC_BUSY;
1555     }
1556 
1557     /* If monitoring is active, update counter. */
1558     if (channel_subsys.chnmon_active) {
1559         css_update_chnmon(sch);
1560     }
1561     sch->orb = *orb;
1562     sch->channel_prog = orb->cpa;
1563     /* Trigger the start function. */
1564     schib->scsw.ctrl |= (SCSW_FCTL_START_FUNC | SCSW_ACTL_START_PEND);
1565     schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1566 
1567     return do_subchannel_work(sch);
1568 }
1569 
1570 static void copy_irb_to_guest(IRB *dest, const IRB *src, const PMCW *pmcw,
1571                               int *irb_len)
1572 {
1573     int i;
1574     uint16_t stctl = src->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1575     uint16_t actl = src->scsw.ctrl & SCSW_CTRL_MASK_ACTL;
1576 
1577     copy_scsw_to_guest(&dest->scsw, &src->scsw);
1578 
1579     for (i = 0; i < ARRAY_SIZE(dest->esw); i++) {
1580         dest->esw[i] = cpu_to_be32(src->esw[i]);
1581     }
1582     for (i = 0; i < ARRAY_SIZE(dest->ecw); i++) {
1583         dest->ecw[i] = cpu_to_be32(src->ecw[i]);
1584     }
1585     *irb_len = sizeof(*dest) - sizeof(dest->emw);
1586 
1587     /* extended measurements enabled? */
1588     if ((src->scsw.flags & SCSW_FLAGS_MASK_ESWF) ||
1589         !(pmcw->flags & PMCW_FLAGS_MASK_TF) ||
1590         !(pmcw->chars & PMCW_CHARS_MASK_XMWME)) {
1591         return;
1592     }
1593     /* extended measurements pending? */
1594     if (!(stctl & SCSW_STCTL_STATUS_PEND)) {
1595         return;
1596     }
1597     if ((stctl & SCSW_STCTL_PRIMARY) ||
1598         (stctl == SCSW_STCTL_SECONDARY) ||
1599         ((stctl & SCSW_STCTL_INTERMEDIATE) && (actl & SCSW_ACTL_SUSP))) {
1600         for (i = 0; i < ARRAY_SIZE(dest->emw); i++) {
1601             dest->emw[i] = cpu_to_be32(src->emw[i]);
1602         }
1603     }
1604     *irb_len = sizeof(*dest);
1605 }
1606 
1607 int css_do_tsch_get_irb(SubchDev *sch, IRB *target_irb, int *irb_len)
1608 {
1609     SCHIB *schib = &sch->curr_status;
1610     PMCW p;
1611     uint16_t stctl;
1612     IRB irb;
1613 
1614     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1615         return 3;
1616     }
1617 
1618     stctl = schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1619 
1620     /* Prepare the irb for the guest. */
1621     memset(&irb, 0, sizeof(IRB));
1622 
1623     /* Copy scsw from current status. */
1624     irb.scsw = schib->scsw;
1625     if (stctl & SCSW_STCTL_STATUS_PEND) {
1626         if (schib->scsw.cstat & (SCSW_CSTAT_DATA_CHECK |
1627                         SCSW_CSTAT_CHN_CTRL_CHK |
1628                         SCSW_CSTAT_INTF_CTRL_CHK)) {
1629             irb.scsw.flags |= SCSW_FLAGS_MASK_ESWF;
1630             irb.esw[0] = 0x04804000;
1631         } else {
1632             irb.esw[0] = 0x00800000;
1633         }
1634         /* If a unit check is pending, copy sense data. */
1635         if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
1636             (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
1637             int i;
1638 
1639             irb.scsw.flags |= SCSW_FLAGS_MASK_ESWF | SCSW_FLAGS_MASK_ECTL;
1640             /* Attention: sense_data is already BE! */
1641             memcpy(irb.ecw, sch->sense_data, sizeof(sch->sense_data));
1642             for (i = 0; i < ARRAY_SIZE(irb.ecw); i++) {
1643                 irb.ecw[i] = be32_to_cpu(irb.ecw[i]);
1644             }
1645             irb.esw[1] = 0x01000000 | (sizeof(sch->sense_data) << 8);
1646         }
1647     }
1648     /* Store the irb to the guest. */
1649     p = schib->pmcw;
1650     copy_irb_to_guest(target_irb, &irb, &p, irb_len);
1651 
1652     return ((stctl & SCSW_STCTL_STATUS_PEND) == 0);
1653 }
1654 
1655 void css_do_tsch_update_subch(SubchDev *sch)
1656 {
1657     SCHIB *schib = &sch->curr_status;
1658     uint16_t stctl;
1659     uint16_t fctl;
1660     uint16_t actl;
1661 
1662     stctl = schib->scsw.ctrl & SCSW_CTRL_MASK_STCTL;
1663     fctl = schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL;
1664     actl = schib->scsw.ctrl & SCSW_CTRL_MASK_ACTL;
1665 
1666     /* Clear conditions on subchannel, if applicable. */
1667     if (stctl & SCSW_STCTL_STATUS_PEND) {
1668         schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
1669         if ((stctl != (SCSW_STCTL_INTERMEDIATE | SCSW_STCTL_STATUS_PEND)) ||
1670             ((fctl & SCSW_FCTL_HALT_FUNC) &&
1671              (actl & SCSW_ACTL_SUSP))) {
1672             schib->scsw.ctrl &= ~SCSW_CTRL_MASK_FCTL;
1673         }
1674         if (stctl != (SCSW_STCTL_INTERMEDIATE | SCSW_STCTL_STATUS_PEND)) {
1675             schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1676             schib->scsw.ctrl &= ~(SCSW_ACTL_RESUME_PEND |
1677                          SCSW_ACTL_START_PEND |
1678                          SCSW_ACTL_HALT_PEND |
1679                          SCSW_ACTL_CLEAR_PEND |
1680                          SCSW_ACTL_SUSP);
1681         } else {
1682             if ((actl & SCSW_ACTL_SUSP) &&
1683                 (fctl & SCSW_FCTL_START_FUNC)) {
1684                 schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO;
1685                 if (fctl & SCSW_FCTL_HALT_FUNC) {
1686                     schib->scsw.ctrl &= ~(SCSW_ACTL_RESUME_PEND |
1687                                  SCSW_ACTL_START_PEND |
1688                                  SCSW_ACTL_HALT_PEND |
1689                                  SCSW_ACTL_CLEAR_PEND |
1690                                  SCSW_ACTL_SUSP);
1691                 } else {
1692                     schib->scsw.ctrl &= ~SCSW_ACTL_RESUME_PEND;
1693                 }
1694             }
1695         }
1696         /* Clear pending sense data. */
1697         if (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE) {
1698             memset(sch->sense_data, 0 , sizeof(sch->sense_data));
1699         }
1700     }
1701 }
1702 
1703 static void copy_crw_to_guest(CRW *dest, const CRW *src)
1704 {
1705     dest->flags = cpu_to_be16(src->flags);
1706     dest->rsid = cpu_to_be16(src->rsid);
1707 }
1708 
1709 int css_do_stcrw(CRW *crw)
1710 {
1711     CrwContainer *crw_cont;
1712     int ret;
1713 
1714     crw_cont = QTAILQ_FIRST(&channel_subsys.pending_crws);
1715     if (crw_cont) {
1716         QTAILQ_REMOVE(&channel_subsys.pending_crws, crw_cont, sibling);
1717         copy_crw_to_guest(crw, &crw_cont->crw);
1718         g_free(crw_cont);
1719         ret = 0;
1720     } else {
1721         /* List was empty, turn crw machine checks on again. */
1722         memset(crw, 0, sizeof(*crw));
1723         channel_subsys.do_crw_mchk = true;
1724         ret = 1;
1725     }
1726 
1727     return ret;
1728 }
1729 
1730 static void copy_crw_from_guest(CRW *dest, const CRW *src)
1731 {
1732     dest->flags = be16_to_cpu(src->flags);
1733     dest->rsid = be16_to_cpu(src->rsid);
1734 }
1735 
1736 void css_undo_stcrw(CRW *crw)
1737 {
1738     CrwContainer *crw_cont;
1739 
1740     crw_cont = g_try_new0(CrwContainer, 1);
1741     if (!crw_cont) {
1742         channel_subsys.crws_lost = true;
1743         return;
1744     }
1745     copy_crw_from_guest(&crw_cont->crw, crw);
1746 
1747     QTAILQ_INSERT_HEAD(&channel_subsys.pending_crws, crw_cont, sibling);
1748 }
1749 
1750 int css_collect_chp_desc(int m, uint8_t cssid, uint8_t f_chpid, uint8_t l_chpid,
1751                          int rfmt, void *buf)
1752 {
1753     int i, desc_size;
1754     uint32_t words[8];
1755     uint32_t chpid_type_word;
1756     CssImage *css;
1757 
1758     if (!m && !cssid) {
1759         css = channel_subsys.css[channel_subsys.default_cssid];
1760     } else {
1761         css = channel_subsys.css[cssid];
1762     }
1763     if (!css) {
1764         return 0;
1765     }
1766     desc_size = 0;
1767     for (i = f_chpid; i <= l_chpid; i++) {
1768         if (css->chpids[i].in_use) {
1769             chpid_type_word = 0x80000000 | (css->chpids[i].type << 8) | i;
1770             if (rfmt == 0) {
1771                 words[0] = cpu_to_be32(chpid_type_word);
1772                 words[1] = 0;
1773                 memcpy(buf + desc_size, words, 8);
1774                 desc_size += 8;
1775             } else if (rfmt == 1) {
1776                 words[0] = cpu_to_be32(chpid_type_word);
1777                 words[1] = 0;
1778                 words[2] = 0;
1779                 words[3] = 0;
1780                 words[4] = 0;
1781                 words[5] = 0;
1782                 words[6] = 0;
1783                 words[7] = 0;
1784                 memcpy(buf + desc_size, words, 32);
1785                 desc_size += 32;
1786             }
1787         }
1788     }
1789     return desc_size;
1790 }
1791 
1792 void css_do_schm(uint8_t mbk, int update, int dct, uint64_t mbo)
1793 {
1794     /* dct is currently ignored (not really meaningful for our devices) */
1795     /* TODO: Don't ignore mbk. */
1796     if (update && !channel_subsys.chnmon_active) {
1797         /* Enable measuring. */
1798         channel_subsys.chnmon_area = mbo;
1799         channel_subsys.chnmon_active = true;
1800     }
1801     if (!update && channel_subsys.chnmon_active) {
1802         /* Disable measuring. */
1803         channel_subsys.chnmon_area = 0;
1804         channel_subsys.chnmon_active = false;
1805     }
1806 }
1807 
1808 IOInstEnding css_do_rsch(SubchDev *sch)
1809 {
1810     SCHIB *schib = &sch->curr_status;
1811 
1812     if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
1813         return IOINST_CC_NOT_OPERATIONAL;
1814     }
1815 
1816     if (schib->scsw.ctrl & SCSW_STCTL_STATUS_PEND) {
1817         return IOINST_CC_STATUS_PRESENT;
1818     }
1819 
1820     if (((schib->scsw.ctrl & SCSW_CTRL_MASK_FCTL) != SCSW_FCTL_START_FUNC) ||
1821         (schib->scsw.ctrl & SCSW_ACTL_RESUME_PEND) ||
1822         (!(schib->scsw.ctrl & SCSW_ACTL_SUSP))) {
1823         return IOINST_CC_BUSY;
1824     }
1825 
1826     /* If monitoring is active, update counter. */
1827     if (channel_subsys.chnmon_active) {
1828         css_update_chnmon(sch);
1829     }
1830 
1831     schib->scsw.ctrl |= SCSW_ACTL_RESUME_PEND;
1832     return do_subchannel_work(sch);
1833 }
1834 
1835 int css_do_rchp(uint8_t cssid, uint8_t chpid)
1836 {
1837     uint8_t real_cssid;
1838 
1839     if (cssid > channel_subsys.max_cssid) {
1840         return -EINVAL;
1841     }
1842     if (channel_subsys.max_cssid == 0) {
1843         real_cssid = channel_subsys.default_cssid;
1844     } else {
1845         real_cssid = cssid;
1846     }
1847     if (!channel_subsys.css[real_cssid]) {
1848         return -EINVAL;
1849     }
1850 
1851     if (!channel_subsys.css[real_cssid]->chpids[chpid].in_use) {
1852         return -ENODEV;
1853     }
1854 
1855     if (!channel_subsys.css[real_cssid]->chpids[chpid].is_virtual) {
1856         fprintf(stderr,
1857                 "rchp unsupported for non-virtual chpid %x.%02x!\n",
1858                 real_cssid, chpid);
1859         return -ENODEV;
1860     }
1861 
1862     /* We don't really use a channel path, so we're done here. */
1863     css_queue_crw(CRW_RSC_CHP, CRW_ERC_INIT, 1,
1864                   channel_subsys.max_cssid > 0 ? 1 : 0, chpid);
1865     if (channel_subsys.max_cssid > 0) {
1866         css_queue_crw(CRW_RSC_CHP, CRW_ERC_INIT, 1, 0, real_cssid << 8);
1867     }
1868     return 0;
1869 }
1870 
1871 bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid)
1872 {
1873     SubchSet *set;
1874     uint8_t real_cssid;
1875 
1876     real_cssid = (!m && (cssid == 0)) ? channel_subsys.default_cssid : cssid;
1877     if (ssid > MAX_SSID ||
1878         !channel_subsys.css[real_cssid] ||
1879         !channel_subsys.css[real_cssid]->sch_set[ssid]) {
1880         return true;
1881     }
1882     set = channel_subsys.css[real_cssid]->sch_set[ssid];
1883     return schid > find_last_bit(set->schids_used,
1884                                  (MAX_SCHID + 1) / sizeof(unsigned long));
1885 }
1886 
1887 unsigned int css_find_free_chpid(uint8_t cssid)
1888 {
1889     CssImage *css = channel_subsys.css[cssid];
1890     unsigned int chpid;
1891 
1892     if (!css) {
1893         return MAX_CHPID + 1;
1894     }
1895 
1896     for (chpid = 0; chpid <= MAX_CHPID; chpid++) {
1897         /* skip reserved chpid */
1898         if (chpid == VIRTIO_CCW_CHPID) {
1899             continue;
1900         }
1901         if (!css->chpids[chpid].in_use) {
1902             return chpid;
1903         }
1904     }
1905     return MAX_CHPID + 1;
1906 }
1907 
1908 static int css_add_chpid(uint8_t cssid, uint8_t chpid, uint8_t type,
1909                          bool is_virt)
1910 {
1911     CssImage *css;
1912 
1913     trace_css_chpid_add(cssid, chpid, type);
1914     css = channel_subsys.css[cssid];
1915     if (!css) {
1916         return -EINVAL;
1917     }
1918     if (css->chpids[chpid].in_use) {
1919         return -EEXIST;
1920     }
1921     css->chpids[chpid].in_use = 1;
1922     css->chpids[chpid].type = type;
1923     css->chpids[chpid].is_virtual = is_virt;
1924 
1925     css_generate_chp_crws(cssid, chpid);
1926 
1927     return 0;
1928 }
1929 
1930 void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type)
1931 {
1932     SCHIB *schib = &sch->curr_status;
1933     int i;
1934     CssImage *css = channel_subsys.css[sch->cssid];
1935 
1936     assert(css != NULL);
1937     memset(&schib->pmcw, 0, sizeof(PMCW));
1938     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
1939     schib->pmcw.devno = sch->devno;
1940     /* single path */
1941     schib->pmcw.pim = 0x80;
1942     schib->pmcw.pom = 0xff;
1943     schib->pmcw.pam = 0x80;
1944     schib->pmcw.chpid[0] = chpid;
1945     if (!css->chpids[chpid].in_use) {
1946         css_add_chpid(sch->cssid, chpid, type, true);
1947     }
1948 
1949     memset(&schib->scsw, 0, sizeof(SCSW));
1950     schib->mba = 0;
1951     for (i = 0; i < ARRAY_SIZE(schib->mda); i++) {
1952         schib->mda[i] = 0;
1953     }
1954 }
1955 
1956 SubchDev *css_find_subch(uint8_t m, uint8_t cssid, uint8_t ssid, uint16_t schid)
1957 {
1958     uint8_t real_cssid;
1959 
1960     real_cssid = (!m && (cssid == 0)) ? channel_subsys.default_cssid : cssid;
1961 
1962     if (!channel_subsys.css[real_cssid]) {
1963         return NULL;
1964     }
1965 
1966     if (!channel_subsys.css[real_cssid]->sch_set[ssid]) {
1967         return NULL;
1968     }
1969 
1970     return channel_subsys.css[real_cssid]->sch_set[ssid]->sch[schid];
1971 }
1972 
1973 /**
1974  * Return free device number in subchannel set.
1975  *
1976  * Return index of the first free device number in the subchannel set
1977  * identified by @p cssid and @p ssid, beginning the search at @p
1978  * start and wrapping around at MAX_DEVNO. Return a value exceeding
1979  * MAX_SCHID if there are no free device numbers in the subchannel
1980  * set.
1981  */
1982 static uint32_t css_find_free_devno(uint8_t cssid, uint8_t ssid,
1983                                     uint16_t start)
1984 {
1985     uint32_t round;
1986 
1987     for (round = 0; round <= MAX_DEVNO; round++) {
1988         uint16_t devno = (start + round) % MAX_DEVNO;
1989 
1990         if (!css_devno_used(cssid, ssid, devno)) {
1991             return devno;
1992         }
1993     }
1994     return MAX_DEVNO + 1;
1995 }
1996 
1997 /**
1998  * Return first free subchannel (id) in subchannel set.
1999  *
2000  * Return index of the first free subchannel in the subchannel set
2001  * identified by @p cssid and @p ssid, if there is any. Return a value
2002  * exceeding MAX_SCHID if there are no free subchannels in the
2003  * subchannel set.
2004  */
2005 static uint32_t css_find_free_subch(uint8_t cssid, uint8_t ssid)
2006 {
2007     uint32_t schid;
2008 
2009     for (schid = 0; schid <= MAX_SCHID; schid++) {
2010         if (!css_find_subch(1, cssid, ssid, schid)) {
2011             return schid;
2012         }
2013     }
2014     return MAX_SCHID + 1;
2015 }
2016 
2017 /**
2018  * Return first free subchannel (id) in subchannel set for a device number
2019  *
2020  * Verify the device number @p devno is not used yet in the subchannel
2021  * set identified by @p cssid and @p ssid. Set @p schid to the index
2022  * of the first free subchannel in the subchannel set, if there is
2023  * any. Return true if everything succeeded and false otherwise.
2024  */
2025 static bool css_find_free_subch_for_devno(uint8_t cssid, uint8_t ssid,
2026                                           uint16_t devno, uint16_t *schid,
2027                                           Error **errp)
2028 {
2029     uint32_t free_schid;
2030 
2031     assert(schid);
2032     if (css_devno_used(cssid, ssid, devno)) {
2033         error_setg(errp, "Device %x.%x.%04x already exists",
2034                    cssid, ssid, devno);
2035         return false;
2036     }
2037     free_schid = css_find_free_subch(cssid, ssid);
2038     if (free_schid > MAX_SCHID) {
2039         error_setg(errp, "No free subchannel found for %x.%x.%04x",
2040                    cssid, ssid, devno);
2041         return false;
2042     }
2043     *schid = free_schid;
2044     return true;
2045 }
2046 
2047 /**
2048  * Return first free subchannel (id) and device number
2049  *
2050  * Locate the first free subchannel and first free device number in
2051  * any of the subchannel sets of the channel subsystem identified by
2052  * @p cssid. Return false if no free subchannel / device number could
2053  * be found. Otherwise set @p ssid, @p devno and @p schid to identify
2054  * the available subchannel and device number and return true.
2055  *
2056  * May modify @p ssid, @p devno and / or @p schid even if no free
2057  * subchannel / device number could be found.
2058  */
2059 static bool css_find_free_subch_and_devno(uint8_t cssid, uint8_t *ssid,
2060                                           uint16_t *devno, uint16_t *schid,
2061                                           Error **errp)
2062 {
2063     uint32_t free_schid, free_devno;
2064 
2065     assert(ssid && devno && schid);
2066     for (*ssid = 0; *ssid <= MAX_SSID; (*ssid)++) {
2067         free_schid = css_find_free_subch(cssid, *ssid);
2068         if (free_schid > MAX_SCHID) {
2069             continue;
2070         }
2071         free_devno = css_find_free_devno(cssid, *ssid, free_schid);
2072         if (free_devno > MAX_DEVNO) {
2073             continue;
2074         }
2075         *schid = free_schid;
2076         *devno = free_devno;
2077         return true;
2078     }
2079     error_setg(errp, "Virtual channel subsystem is full!");
2080     return false;
2081 }
2082 
2083 bool css_subch_visible(SubchDev *sch)
2084 {
2085     if (sch->ssid > channel_subsys.max_ssid) {
2086         return false;
2087     }
2088 
2089     if (sch->cssid != channel_subsys.default_cssid) {
2090         return (channel_subsys.max_cssid > 0);
2091     }
2092 
2093     return true;
2094 }
2095 
2096 bool css_present(uint8_t cssid)
2097 {
2098     return (channel_subsys.css[cssid] != NULL);
2099 }
2100 
2101 bool css_devno_used(uint8_t cssid, uint8_t ssid, uint16_t devno)
2102 {
2103     if (!channel_subsys.css[cssid]) {
2104         return false;
2105     }
2106     if (!channel_subsys.css[cssid]->sch_set[ssid]) {
2107         return false;
2108     }
2109 
2110     return !!test_bit(devno,
2111                       channel_subsys.css[cssid]->sch_set[ssid]->devnos_used);
2112 }
2113 
2114 void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,
2115                       uint16_t devno, SubchDev *sch)
2116 {
2117     CssImage *css;
2118     SubchSet *s_set;
2119 
2120     trace_css_assign_subch(sch ? "assign" : "deassign", cssid, ssid, schid,
2121                            devno);
2122     if (!channel_subsys.css[cssid]) {
2123         fprintf(stderr,
2124                 "Suspicious call to %s (%x.%x.%04x) for non-existing css!\n",
2125                 __func__, cssid, ssid, schid);
2126         return;
2127     }
2128     css = channel_subsys.css[cssid];
2129 
2130     if (!css->sch_set[ssid]) {
2131         css->sch_set[ssid] = g_new0(SubchSet, 1);
2132     }
2133     s_set = css->sch_set[ssid];
2134 
2135     s_set->sch[schid] = sch;
2136     if (sch) {
2137         set_bit(schid, s_set->schids_used);
2138         set_bit(devno, s_set->devnos_used);
2139     } else {
2140         clear_bit(schid, s_set->schids_used);
2141         clear_bit(devno, s_set->devnos_used);
2142     }
2143 }
2144 
2145 void css_queue_crw(uint8_t rsc, uint8_t erc, int solicited,
2146                    int chain, uint16_t rsid)
2147 {
2148     CrwContainer *crw_cont;
2149 
2150     trace_css_crw(rsc, erc, rsid, chain ? "(chained)" : "");
2151     /* TODO: Maybe use a static crw pool? */
2152     crw_cont = g_try_new0(CrwContainer, 1);
2153     if (!crw_cont) {
2154         channel_subsys.crws_lost = true;
2155         return;
2156     }
2157     crw_cont->crw.flags = (rsc << 8) | erc;
2158     if (solicited) {
2159         crw_cont->crw.flags |= CRW_FLAGS_MASK_S;
2160     }
2161     if (chain) {
2162         crw_cont->crw.flags |= CRW_FLAGS_MASK_C;
2163     }
2164     crw_cont->crw.rsid = rsid;
2165     if (channel_subsys.crws_lost) {
2166         crw_cont->crw.flags |= CRW_FLAGS_MASK_R;
2167         channel_subsys.crws_lost = false;
2168     }
2169 
2170     QTAILQ_INSERT_TAIL(&channel_subsys.pending_crws, crw_cont, sibling);
2171 
2172     if (channel_subsys.do_crw_mchk) {
2173         channel_subsys.do_crw_mchk = false;
2174         /* Inject crw pending machine check. */
2175         s390_crw_mchk();
2176     }
2177 }
2178 
2179 void css_generate_sch_crws(uint8_t cssid, uint8_t ssid, uint16_t schid,
2180                            int hotplugged, int add)
2181 {
2182     uint8_t guest_cssid;
2183     bool chain_crw;
2184 
2185     if (add && !hotplugged) {
2186         return;
2187     }
2188     if (channel_subsys.max_cssid == 0) {
2189         /* Default cssid shows up as 0. */
2190         guest_cssid = (cssid == channel_subsys.default_cssid) ? 0 : cssid;
2191     } else {
2192         /* Show real cssid to the guest. */
2193         guest_cssid = cssid;
2194     }
2195     /*
2196      * Only notify for higher subchannel sets/channel subsystems if the
2197      * guest has enabled it.
2198      */
2199     if ((ssid > channel_subsys.max_ssid) ||
2200         (guest_cssid > channel_subsys.max_cssid) ||
2201         ((channel_subsys.max_cssid == 0) &&
2202          (cssid != channel_subsys.default_cssid))) {
2203         return;
2204     }
2205     chain_crw = (channel_subsys.max_ssid > 0) ||
2206             (channel_subsys.max_cssid > 0);
2207     css_queue_crw(CRW_RSC_SUBCH, CRW_ERC_IPI, 0, chain_crw ? 1 : 0, schid);
2208     if (chain_crw) {
2209         css_queue_crw(CRW_RSC_SUBCH, CRW_ERC_IPI, 0, 0,
2210                       (guest_cssid << 8) | (ssid << 4));
2211     }
2212     /* RW_ERC_IPI --> clear pending interrupts */
2213     css_clear_io_interrupt(css_do_build_subchannel_id(cssid, ssid), schid);
2214 }
2215 
2216 void css_generate_chp_crws(uint8_t cssid, uint8_t chpid)
2217 {
2218     /* TODO */
2219 }
2220 
2221 void css_generate_css_crws(uint8_t cssid)
2222 {
2223     if (!channel_subsys.sei_pending) {
2224         css_queue_crw(CRW_RSC_CSS, CRW_ERC_EVENT, 0, 0, cssid);
2225     }
2226     channel_subsys.sei_pending = true;
2227 }
2228 
2229 void css_clear_sei_pending(void)
2230 {
2231     channel_subsys.sei_pending = false;
2232 }
2233 
2234 int css_enable_mcsse(void)
2235 {
2236     trace_css_enable_facility("mcsse");
2237     channel_subsys.max_cssid = MAX_CSSID;
2238     return 0;
2239 }
2240 
2241 int css_enable_mss(void)
2242 {
2243     trace_css_enable_facility("mss");
2244     channel_subsys.max_ssid = MAX_SSID;
2245     return 0;
2246 }
2247 
2248 void css_reset_sch(SubchDev *sch)
2249 {
2250     SCHIB *schib = &sch->curr_status;
2251 
2252     if ((schib->pmcw.flags & PMCW_FLAGS_MASK_ENA) != 0 && sch->disable_cb) {
2253         sch->disable_cb(sch);
2254     }
2255 
2256     schib->pmcw.intparm = 0;
2257     schib->pmcw.flags &= ~(PMCW_FLAGS_MASK_ISC | PMCW_FLAGS_MASK_ENA |
2258                   PMCW_FLAGS_MASK_LM | PMCW_FLAGS_MASK_MME |
2259                   PMCW_FLAGS_MASK_MP | PMCW_FLAGS_MASK_TF);
2260     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
2261     schib->pmcw.devno = sch->devno;
2262     schib->pmcw.pim = 0x80;
2263     schib->pmcw.lpm = schib->pmcw.pim;
2264     schib->pmcw.pnom = 0;
2265     schib->pmcw.lpum = 0;
2266     schib->pmcw.mbi = 0;
2267     schib->pmcw.pom = 0xff;
2268     schib->pmcw.pam = 0x80;
2269     schib->pmcw.chars &= ~(PMCW_CHARS_MASK_MBFC | PMCW_CHARS_MASK_XMWME |
2270                   PMCW_CHARS_MASK_CSENSE);
2271 
2272     memset(&schib->scsw, 0, sizeof(schib->scsw));
2273     schib->mba = 0;
2274 
2275     sch->channel_prog = 0x0;
2276     sch->last_cmd_valid = false;
2277     sch->thinint_active = false;
2278 }
2279 
2280 void css_reset(void)
2281 {
2282     CrwContainer *crw_cont;
2283 
2284     /* Clean up monitoring. */
2285     channel_subsys.chnmon_active = false;
2286     channel_subsys.chnmon_area = 0;
2287 
2288     /* Clear pending CRWs. */
2289     while ((crw_cont = QTAILQ_FIRST(&channel_subsys.pending_crws))) {
2290         QTAILQ_REMOVE(&channel_subsys.pending_crws, crw_cont, sibling);
2291         g_free(crw_cont);
2292     }
2293     channel_subsys.sei_pending = false;
2294     channel_subsys.do_crw_mchk = true;
2295     channel_subsys.crws_lost = false;
2296 
2297     /* Reset maximum ids. */
2298     channel_subsys.max_cssid = 0;
2299     channel_subsys.max_ssid = 0;
2300 }
2301 
2302 static void get_css_devid(Object *obj, Visitor *v, const char *name,
2303                           void *opaque, Error **errp)
2304 {
2305     DeviceState *dev = DEVICE(obj);
2306     Property *prop = opaque;
2307     CssDevId *dev_id = qdev_get_prop_ptr(dev, prop);
2308     char buffer[] = "xx.x.xxxx";
2309     char *p = buffer;
2310     int r;
2311 
2312     if (dev_id->valid) {
2313 
2314         r = snprintf(buffer, sizeof(buffer), "%02x.%1x.%04x", dev_id->cssid,
2315                      dev_id->ssid, dev_id->devid);
2316         assert(r == sizeof(buffer) - 1);
2317 
2318         /* drop leading zero */
2319         if (dev_id->cssid <= 0xf) {
2320             p++;
2321         }
2322     } else {
2323         snprintf(buffer, sizeof(buffer), "<unset>");
2324     }
2325 
2326     visit_type_str(v, name, &p, errp);
2327 }
2328 
2329 /*
2330  * parse <cssid>.<ssid>.<devid> and assert valid range for cssid/ssid
2331  */
2332 static void set_css_devid(Object *obj, Visitor *v, const char *name,
2333                           void *opaque, Error **errp)
2334 {
2335     DeviceState *dev = DEVICE(obj);
2336     Property *prop = opaque;
2337     CssDevId *dev_id = qdev_get_prop_ptr(dev, prop);
2338     Error *local_err = NULL;
2339     char *str;
2340     int num, n1, n2;
2341     unsigned int cssid, ssid, devid;
2342 
2343     if (dev->realized) {
2344         qdev_prop_set_after_realize(dev, name, errp);
2345         return;
2346     }
2347 
2348     visit_type_str(v, name, &str, &local_err);
2349     if (local_err) {
2350         error_propagate(errp, local_err);
2351         return;
2352     }
2353 
2354     num = sscanf(str, "%2x.%1x%n.%4x%n", &cssid, &ssid, &n1, &devid, &n2);
2355     if (num != 3 || (n2 - n1) != 5 || strlen(str) != n2) {
2356         error_set_from_qdev_prop_error(errp, EINVAL, dev, prop, str);
2357         goto out;
2358     }
2359     if ((cssid > MAX_CSSID) || (ssid > MAX_SSID)) {
2360         error_setg(errp, "Invalid cssid or ssid: cssid %x, ssid %x",
2361                    cssid, ssid);
2362         goto out;
2363     }
2364 
2365     dev_id->cssid = cssid;
2366     dev_id->ssid = ssid;
2367     dev_id->devid = devid;
2368     dev_id->valid = true;
2369 
2370 out:
2371     g_free(str);
2372 }
2373 
2374 const PropertyInfo css_devid_propinfo = {
2375     .name = "str",
2376     .description = "Identifier of an I/O device in the channel "
2377                    "subsystem, example: fe.1.23ab",
2378     .get = get_css_devid,
2379     .set = set_css_devid,
2380 };
2381 
2382 const PropertyInfo css_devid_ro_propinfo = {
2383     .name = "str",
2384     .description = "Read-only identifier of an I/O device in the channel "
2385                    "subsystem, example: fe.1.23ab",
2386     .get = get_css_devid,
2387 };
2388 
2389 SubchDev *css_create_sch(CssDevId bus_id, Error **errp)
2390 {
2391     uint16_t schid = 0;
2392     SubchDev *sch;
2393 
2394     if (bus_id.valid) {
2395         if (!channel_subsys.css[bus_id.cssid]) {
2396             css_create_css_image(bus_id.cssid, false);
2397         }
2398 
2399         if (!css_find_free_subch_for_devno(bus_id.cssid, bus_id.ssid,
2400                                            bus_id.devid, &schid, errp)) {
2401             return NULL;
2402         }
2403     } else {
2404         for (bus_id.cssid = channel_subsys.default_cssid;;) {
2405             if (!channel_subsys.css[bus_id.cssid]) {
2406                 css_create_css_image(bus_id.cssid, false);
2407             }
2408 
2409             if   (css_find_free_subch_and_devno(bus_id.cssid, &bus_id.ssid,
2410                                                 &bus_id.devid, &schid,
2411                                                 NULL)) {
2412                 break;
2413             }
2414             bus_id.cssid = (bus_id.cssid + 1) % MAX_CSSID;
2415             if (bus_id.cssid == channel_subsys.default_cssid) {
2416                 error_setg(errp, "Virtual channel subsystem is full!");
2417                 return NULL;
2418             }
2419         }
2420     }
2421 
2422     sch = g_new0(SubchDev, 1);
2423     sch->cssid = bus_id.cssid;
2424     sch->ssid = bus_id.ssid;
2425     sch->devno = bus_id.devid;
2426     sch->schid = schid;
2427     css_subch_assign(sch->cssid, sch->ssid, schid, sch->devno, sch);
2428     return sch;
2429 }
2430 
2431 static int css_sch_get_chpids(SubchDev *sch, CssDevId *dev_id)
2432 {
2433     char *fid_path;
2434     FILE *fd;
2435     uint32_t chpid[8];
2436     int i;
2437     SCHIB *schib = &sch->curr_status;
2438 
2439     fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/chpids",
2440                                dev_id->cssid, dev_id->ssid, dev_id->devid);
2441     fd = fopen(fid_path, "r");
2442     if (fd == NULL) {
2443         error_report("%s: open %s failed", __func__, fid_path);
2444         g_free(fid_path);
2445         return -EINVAL;
2446     }
2447 
2448     if (fscanf(fd, "%x %x %x %x %x %x %x %x",
2449         &chpid[0], &chpid[1], &chpid[2], &chpid[3],
2450         &chpid[4], &chpid[5], &chpid[6], &chpid[7]) != 8) {
2451         fclose(fd);
2452         g_free(fid_path);
2453         return -EINVAL;
2454     }
2455 
2456     for (i = 0; i < ARRAY_SIZE(schib->pmcw.chpid); i++) {
2457         schib->pmcw.chpid[i] = chpid[i];
2458     }
2459 
2460     fclose(fd);
2461     g_free(fid_path);
2462 
2463     return 0;
2464 }
2465 
2466 static int css_sch_get_path_masks(SubchDev *sch, CssDevId *dev_id)
2467 {
2468     char *fid_path;
2469     FILE *fd;
2470     uint32_t pim, pam, pom;
2471     SCHIB *schib = &sch->curr_status;
2472 
2473     fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/pimpampom",
2474                                dev_id->cssid, dev_id->ssid, dev_id->devid);
2475     fd = fopen(fid_path, "r");
2476     if (fd == NULL) {
2477         error_report("%s: open %s failed", __func__, fid_path);
2478         g_free(fid_path);
2479         return -EINVAL;
2480     }
2481 
2482     if (fscanf(fd, "%x %x %x", &pim, &pam, &pom) != 3) {
2483         fclose(fd);
2484         g_free(fid_path);
2485         return -EINVAL;
2486     }
2487 
2488     schib->pmcw.pim = pim;
2489     schib->pmcw.pam = pam;
2490     schib->pmcw.pom = pom;
2491     fclose(fd);
2492     g_free(fid_path);
2493 
2494     return 0;
2495 }
2496 
2497 static int css_sch_get_chpid_type(uint8_t chpid, uint32_t *type,
2498                                   CssDevId *dev_id)
2499 {
2500     char *fid_path;
2501     FILE *fd;
2502 
2503     fid_path = g_strdup_printf("/sys/devices/css%x/chp0.%02x/type",
2504                                dev_id->cssid, chpid);
2505     fd = fopen(fid_path, "r");
2506     if (fd == NULL) {
2507         error_report("%s: open %s failed", __func__, fid_path);
2508         g_free(fid_path);
2509         return -EINVAL;
2510     }
2511 
2512     if (fscanf(fd, "%x", type) != 1) {
2513         fclose(fd);
2514         g_free(fid_path);
2515         return -EINVAL;
2516     }
2517 
2518     fclose(fd);
2519     g_free(fid_path);
2520 
2521     return 0;
2522 }
2523 
2524 /*
2525  * We currently retrieve the real device information from sysfs to build the
2526  * guest subchannel information block without considering the migration feature.
2527  * We need to revisit this problem when we want to add migration support.
2528  */
2529 int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id)
2530 {
2531     CssImage *css = channel_subsys.css[sch->cssid];
2532     SCHIB *schib = &sch->curr_status;
2533     uint32_t type;
2534     int i, ret;
2535 
2536     assert(css != NULL);
2537     memset(&schib->pmcw, 0, sizeof(PMCW));
2538     schib->pmcw.flags |= PMCW_FLAGS_MASK_DNV;
2539     /* We are dealing with I/O subchannels only. */
2540     schib->pmcw.devno = sch->devno;
2541 
2542     /* Grab path mask from sysfs. */
2543     ret = css_sch_get_path_masks(sch, dev_id);
2544     if (ret) {
2545         return ret;
2546     }
2547 
2548     /* Grab chpids from sysfs. */
2549     ret = css_sch_get_chpids(sch, dev_id);
2550     if (ret) {
2551         return ret;
2552     }
2553 
2554    /* Build chpid type. */
2555     for (i = 0; i < ARRAY_SIZE(schib->pmcw.chpid); i++) {
2556         if (schib->pmcw.chpid[i] && !css->chpids[schib->pmcw.chpid[i]].in_use) {
2557             ret = css_sch_get_chpid_type(schib->pmcw.chpid[i], &type, dev_id);
2558             if (ret) {
2559                 return ret;
2560             }
2561             css_add_chpid(sch->cssid, schib->pmcw.chpid[i], type, false);
2562         }
2563     }
2564 
2565     memset(&schib->scsw, 0, sizeof(SCSW));
2566     schib->mba = 0;
2567     for (i = 0; i < ARRAY_SIZE(schib->mda); i++) {
2568         schib->mda[i] = 0;
2569     }
2570 
2571     return 0;
2572 }
2573