xref: /openbmc/qemu/hw/scsi/spapr_vscsi.c (revision c2cb92f9ea3c88acde6a8cb75abc148dfe27aee7)
1 /*
2  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
3  *
4  * PAPR Virtual SCSI, aka ibmvscsi
5  *
6  * Copyright (c) 2010,2011 Benjamin Herrenschmidt, IBM Corporation.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  *
26  * TODO:
27  *
28  *  - Cleanups :-)
29  *  - Sort out better how to assign devices to VSCSI instances
30  *  - Fix residual counts
31  *  - Add indirect descriptors support
32  *  - Maybe do autosense (PAPR seems to mandate it, linux doesn't care)
33  */
34 #include "hw/hw.h"
35 #include "hw/scsi/scsi.h"
36 #include "block/scsi.h"
37 #include "srp.h"
38 #include "hw/qdev.h"
39 #include "hw/ppc/spapr.h"
40 #include "hw/ppc/spapr_vio.h"
41 #include "viosrp.h"
42 
43 #include <libfdt.h>
44 
45 /*#define DEBUG_VSCSI*/
46 
47 #ifdef DEBUG_VSCSI
48 #define DPRINTF(fmt, ...) \
49     do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
50 #else
51 #define DPRINTF(fmt, ...) \
52     do { } while (0)
53 #endif
54 
55 /*
56  * Virtual SCSI device
57  */
58 
59 /* Random numbers */
60 #define VSCSI_MAX_SECTORS       4096
61 #define VSCSI_REQ_LIMIT         24
62 
63 #define SRP_RSP_SENSE_DATA_LEN  18
64 
65 typedef union vscsi_crq {
66     struct viosrp_crq s;
67     uint8_t raw[16];
68 } vscsi_crq;
69 
70 typedef struct vscsi_req {
71     vscsi_crq               crq;
72     union viosrp_iu         iu;
73 
74     /* SCSI request tracking */
75     SCSIRequest             *sreq;
76     uint32_t                qtag; /* qemu tag != srp tag */
77     bool                    active;
78     uint32_t                data_len;
79     bool                    writing;
80     uint32_t                senselen;
81     uint8_t                 sense[SCSI_SENSE_BUF_SIZE];
82 
83     /* RDMA related bits */
84     uint8_t                 dma_fmt;
85     uint16_t                local_desc;
86     uint16_t                total_desc;
87     uint16_t                cdb_offset;
88     uint16_t                cur_desc_num;
89     uint16_t                cur_desc_offset;
90 } vscsi_req;
91 
92 #define TYPE_VIO_SPAPR_VSCSI_DEVICE "spapr-vscsi"
93 #define VIO_SPAPR_VSCSI_DEVICE(obj) \
94      OBJECT_CHECK(VSCSIState, (obj), TYPE_VIO_SPAPR_VSCSI_DEVICE)
95 
96 typedef struct {
97     VIOsPAPRDevice vdev;
98     SCSIBus bus;
99     vscsi_req reqs[VSCSI_REQ_LIMIT];
100 } VSCSIState;
101 
102 static struct vscsi_req *vscsi_get_req(VSCSIState *s)
103 {
104     vscsi_req *req;
105     int i;
106 
107     for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
108         req = &s->reqs[i];
109         if (!req->active) {
110             memset(req, 0, sizeof(*req));
111             req->qtag = i;
112             req->active = 1;
113             return req;
114         }
115     }
116     return NULL;
117 }
118 
119 static struct vscsi_req *vscsi_find_req(VSCSIState *s, uint64_t srp_tag)
120 {
121     vscsi_req *req;
122     int i;
123 
124     for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
125         req = &s->reqs[i];
126         if (req->iu.srp.cmd.tag == srp_tag) {
127             return req;
128         }
129     }
130     return NULL;
131 }
132 
133 static void vscsi_put_req(vscsi_req *req)
134 {
135     if (req->sreq != NULL) {
136         scsi_req_unref(req->sreq);
137     }
138     req->sreq = NULL;
139     req->active = 0;
140 }
141 
142 static SCSIDevice *vscsi_device_find(SCSIBus *bus, uint64_t srp_lun, int *lun)
143 {
144     int channel = 0, id = 0;
145 
146 retry:
147     switch (srp_lun >> 62) {
148     case 0:
149         if ((srp_lun >> 56) != 0) {
150             channel = (srp_lun >> 56) & 0x3f;
151             id = (srp_lun >> 48) & 0xff;
152             srp_lun <<= 16;
153             goto retry;
154         }
155         *lun = (srp_lun >> 48) & 0xff;
156         break;
157 
158     case 1:
159         *lun = (srp_lun >> 48) & 0x3fff;
160         break;
161     case 2:
162         channel = (srp_lun >> 53) & 0x7;
163         id = (srp_lun >> 56) & 0x3f;
164         *lun = (srp_lun >> 48) & 0x1f;
165         break;
166     case 3:
167         *lun = -1;
168         return NULL;
169     default:
170         abort();
171     }
172 
173     return scsi_device_find(bus, channel, id, *lun);
174 }
175 
176 static int vscsi_send_iu(VSCSIState *s, vscsi_req *req,
177                          uint64_t length, uint8_t format)
178 {
179     long rc, rc1;
180 
181     /* First copy the SRP */
182     rc = spapr_vio_dma_write(&s->vdev, req->crq.s.IU_data_ptr,
183                              &req->iu, length);
184     if (rc) {
185         fprintf(stderr, "vscsi_send_iu: DMA write failure !\n");
186     }
187 
188     req->crq.s.valid = 0x80;
189     req->crq.s.format = format;
190     req->crq.s.reserved = 0x00;
191     req->crq.s.timeout = cpu_to_be16(0x0000);
192     req->crq.s.IU_length = cpu_to_be16(length);
193     req->crq.s.IU_data_ptr = req->iu.srp.rsp.tag; /* right byte order */
194 
195     if (rc == 0) {
196         req->crq.s.status = 0x99; /* Just needs to be non-zero */
197     } else {
198         req->crq.s.status = 0x00;
199     }
200 
201     rc1 = spapr_vio_send_crq(&s->vdev, req->crq.raw);
202     if (rc1) {
203         fprintf(stderr, "vscsi_send_iu: Error sending response\n");
204         return rc1;
205     }
206 
207     return rc;
208 }
209 
210 static void vscsi_makeup_sense(VSCSIState *s, vscsi_req *req,
211                                uint8_t key, uint8_t asc, uint8_t ascq)
212 {
213     req->senselen = SRP_RSP_SENSE_DATA_LEN;
214 
215     /* Valid bit and 'current errors' */
216     req->sense[0] = (0x1 << 7 | 0x70);
217     /* Sense key */
218     req->sense[2] = key;
219     /* Additional sense length */
220     req->sense[7] = 0xa; /* 10 bytes */
221     /* Additional sense code */
222     req->sense[12] = asc;
223     req->sense[13] = ascq;
224 }
225 
226 static int vscsi_send_rsp(VSCSIState *s, vscsi_req *req,
227                           uint8_t status, int32_t res_in, int32_t res_out)
228 {
229     union viosrp_iu *iu = &req->iu;
230     uint64_t tag = iu->srp.rsp.tag;
231     int total_len = sizeof(iu->srp.rsp);
232     uint8_t sol_not = iu->srp.cmd.sol_not;
233 
234     DPRINTF("VSCSI: Sending resp status: 0x%x, "
235             "res_in: %d, res_out: %d\n", status, res_in, res_out);
236 
237     memset(iu, 0, sizeof(struct srp_rsp));
238     iu->srp.rsp.opcode = SRP_RSP;
239     iu->srp.rsp.req_lim_delta = cpu_to_be32(1);
240     iu->srp.rsp.tag = tag;
241 
242     /* Handle residuals */
243     if (res_in < 0) {
244         iu->srp.rsp.flags |= SRP_RSP_FLAG_DIUNDER;
245         res_in = -res_in;
246     } else if (res_in) {
247         iu->srp.rsp.flags |= SRP_RSP_FLAG_DIOVER;
248     }
249     if (res_out < 0) {
250         iu->srp.rsp.flags |= SRP_RSP_FLAG_DOUNDER;
251         res_out = -res_out;
252     } else if (res_out) {
253         iu->srp.rsp.flags |= SRP_RSP_FLAG_DOOVER;
254     }
255     iu->srp.rsp.data_in_res_cnt = cpu_to_be32(res_in);
256     iu->srp.rsp.data_out_res_cnt = cpu_to_be32(res_out);
257 
258     /* We don't do response data */
259     /* iu->srp.rsp.flags &= ~SRP_RSP_FLAG_RSPVALID; */
260     iu->srp.rsp.resp_data_len = cpu_to_be32(0);
261 
262     /* Handle success vs. failure */
263     iu->srp.rsp.status = status;
264     if (status) {
265         iu->srp.rsp.sol_not = (sol_not & 0x04) >> 2;
266         if (req->senselen) {
267             req->iu.srp.rsp.flags |= SRP_RSP_FLAG_SNSVALID;
268             req->iu.srp.rsp.sense_data_len = cpu_to_be32(req->senselen);
269             memcpy(req->iu.srp.rsp.data, req->sense, req->senselen);
270             total_len += req->senselen;
271         }
272     } else {
273         iu->srp.rsp.sol_not = (sol_not & 0x02) >> 1;
274     }
275 
276     vscsi_send_iu(s, req, total_len, VIOSRP_SRP_FORMAT);
277     return 0;
278 }
279 
280 static inline struct srp_direct_buf vscsi_swap_desc(struct srp_direct_buf desc)
281 {
282     desc.va = be64_to_cpu(desc.va);
283     desc.len = be32_to_cpu(desc.len);
284     return desc;
285 }
286 
287 static int vscsi_fetch_desc(VSCSIState *s, struct vscsi_req *req,
288                             unsigned n, unsigned buf_offset,
289                             struct srp_direct_buf *ret)
290 {
291     struct srp_cmd *cmd = &req->iu.srp.cmd;
292 
293     switch (req->dma_fmt) {
294     case SRP_NO_DATA_DESC: {
295         DPRINTF("VSCSI: no data descriptor\n");
296         return 0;
297     }
298     case SRP_DATA_DESC_DIRECT: {
299         memcpy(ret, cmd->add_data + req->cdb_offset, sizeof(*ret));
300         assert(req->cur_desc_num == 0);
301         DPRINTF("VSCSI: direct segment\n");
302         break;
303     }
304     case SRP_DATA_DESC_INDIRECT: {
305         struct srp_indirect_buf *tmp = (struct srp_indirect_buf *)
306                                        (cmd->add_data + req->cdb_offset);
307         if (n < req->local_desc) {
308             *ret = tmp->desc_list[n];
309             DPRINTF("VSCSI: indirect segment local tag=0x%x desc#%d/%d\n",
310                     req->qtag, n, req->local_desc);
311 
312         } else if (n < req->total_desc) {
313             int rc;
314             struct srp_direct_buf tbl_desc = vscsi_swap_desc(tmp->table_desc);
315             unsigned desc_offset = n * sizeof(struct srp_direct_buf);
316 
317             if (desc_offset >= tbl_desc.len) {
318                 DPRINTF("VSCSI:   #%d is ouf of range (%d bytes)\n",
319                         n, desc_offset);
320                 return -1;
321             }
322             rc = spapr_vio_dma_read(&s->vdev, tbl_desc.va + desc_offset,
323                                     ret, sizeof(struct srp_direct_buf));
324             if (rc) {
325                 DPRINTF("VSCSI: spapr_vio_dma_read -> %d reading ext_desc\n",
326                         rc);
327                 return -1;
328             }
329             DPRINTF("VSCSI: indirect segment ext. tag=0x%x desc#%d/%d { va=%"PRIx64" len=%x }\n",
330                     req->qtag, n, req->total_desc, tbl_desc.va, tbl_desc.len);
331         } else {
332             DPRINTF("VSCSI:   Out of descriptors !\n");
333             return 0;
334         }
335         break;
336     }
337     default:
338         fprintf(stderr, "VSCSI:   Unknown format %x\n", req->dma_fmt);
339         return -1;
340     }
341 
342     *ret = vscsi_swap_desc(*ret);
343     if (buf_offset > ret->len) {
344         DPRINTF("   offset=%x is out of a descriptor #%d boundary=%x\n",
345                 buf_offset, req->cur_desc_num, ret->len);
346         return -1;
347     }
348     ret->va += buf_offset;
349     ret->len -= buf_offset;
350 
351     DPRINTF("   cur=%d offs=%x ret { va=%"PRIx64" len=%x }\n",
352             req->cur_desc_num, req->cur_desc_offset, ret->va, ret->len);
353 
354     return ret->len ? 1 : 0;
355 }
356 
357 static int vscsi_srp_direct_data(VSCSIState *s, vscsi_req *req,
358                                  uint8_t *buf, uint32_t len)
359 {
360     struct srp_direct_buf md;
361     uint32_t llen;
362     int rc = 0;
363 
364     rc = vscsi_fetch_desc(s, req, req->cur_desc_num, req->cur_desc_offset, &md);
365     if (rc < 0) {
366         return -1;
367     } else if (rc == 0) {
368         return 0;
369     }
370 
371     llen = MIN(len, md.len);
372     if (llen) {
373         if (req->writing) { /* writing = to device = reading from memory */
374             rc = spapr_vio_dma_read(&s->vdev, md.va, buf, llen);
375         } else {
376             rc = spapr_vio_dma_write(&s->vdev, md.va, buf, llen);
377         }
378     }
379 
380     if (rc) {
381         return -1;
382     }
383     req->cur_desc_offset += llen;
384 
385     return llen;
386 }
387 
388 static int vscsi_srp_indirect_data(VSCSIState *s, vscsi_req *req,
389                                    uint8_t *buf, uint32_t len)
390 {
391     struct srp_direct_buf md;
392     int rc = 0;
393     uint32_t llen, total = 0;
394 
395     DPRINTF("VSCSI: indirect segment 0x%x bytes\n", len);
396 
397     /* While we have data ... */
398     while (len) {
399         rc = vscsi_fetch_desc(s, req, req->cur_desc_num, req->cur_desc_offset, &md);
400         if (rc < 0) {
401             return -1;
402         } else if (rc == 0) {
403             break;
404         }
405 
406         /* Perform transfer */
407         llen = MIN(len, md.len);
408         if (req->writing) { /* writing = to device = reading from memory */
409             rc = spapr_vio_dma_read(&s->vdev, md.va, buf, llen);
410         } else {
411             rc = spapr_vio_dma_write(&s->vdev, md.va, buf, llen);
412         }
413         if (rc) {
414             DPRINTF("VSCSI: spapr_vio_dma_r/w(%d) -> %d\n", req->writing, rc);
415             break;
416         }
417         DPRINTF("VSCSI:     data: %02x %02x %02x %02x...\n",
418                 buf[0], buf[1], buf[2], buf[3]);
419 
420         len -= llen;
421         buf += llen;
422 
423         total += llen;
424 
425         /* Update current position in the current descriptor */
426         req->cur_desc_offset += llen;
427         if (md.len == llen) {
428             /* Go to the next descriptor if the current one finished */
429             ++req->cur_desc_num;
430             req->cur_desc_offset = 0;
431         }
432     }
433 
434     return rc ? -1 : total;
435 }
436 
437 static int vscsi_srp_transfer_data(VSCSIState *s, vscsi_req *req,
438                                    int writing, uint8_t *buf, uint32_t len)
439 {
440     int err = 0;
441 
442     switch (req->dma_fmt) {
443     case SRP_NO_DATA_DESC:
444         DPRINTF("VSCSI: no data desc transfer, skipping 0x%x bytes\n", len);
445         break;
446     case SRP_DATA_DESC_DIRECT:
447         err = vscsi_srp_direct_data(s, req, buf, len);
448         break;
449     case SRP_DATA_DESC_INDIRECT:
450         err = vscsi_srp_indirect_data(s, req, buf, len);
451         break;
452     }
453     return err;
454 }
455 
456 /* Bits from linux srp */
457 static int data_out_desc_size(struct srp_cmd *cmd)
458 {
459     int size = 0;
460     uint8_t fmt = cmd->buf_fmt >> 4;
461 
462     switch (fmt) {
463     case SRP_NO_DATA_DESC:
464         break;
465     case SRP_DATA_DESC_DIRECT:
466         size = sizeof(struct srp_direct_buf);
467         break;
468     case SRP_DATA_DESC_INDIRECT:
469         size = sizeof(struct srp_indirect_buf) +
470             sizeof(struct srp_direct_buf)*cmd->data_out_desc_cnt;
471         break;
472     default:
473         break;
474     }
475     return size;
476 }
477 
478 static int vscsi_preprocess_desc(vscsi_req *req)
479 {
480     struct srp_cmd *cmd = &req->iu.srp.cmd;
481 
482     req->cdb_offset = cmd->add_cdb_len & ~3;
483 
484     if (req->writing) {
485         req->dma_fmt = cmd->buf_fmt >> 4;
486     } else {
487         req->cdb_offset += data_out_desc_size(cmd);
488         req->dma_fmt = cmd->buf_fmt & ((1U << 4) - 1);
489     }
490 
491     switch (req->dma_fmt) {
492     case SRP_NO_DATA_DESC:
493         break;
494     case SRP_DATA_DESC_DIRECT:
495         req->total_desc = req->local_desc = 1;
496         break;
497     case SRP_DATA_DESC_INDIRECT: {
498         struct srp_indirect_buf *ind_tmp = (struct srp_indirect_buf *)
499                 (cmd->add_data + req->cdb_offset);
500 
501         req->total_desc = be32_to_cpu(ind_tmp->table_desc.len) /
502                           sizeof(struct srp_direct_buf);
503         req->local_desc = req->writing ? cmd->data_out_desc_cnt :
504                           cmd->data_in_desc_cnt;
505         break;
506     }
507     default:
508         fprintf(stderr,
509                 "vscsi_preprocess_desc: Unknown format %x\n", req->dma_fmt);
510         return -1;
511     }
512 
513     return 0;
514 }
515 
516 /* Callback to indicate that the SCSI layer has completed a transfer.  */
517 static void vscsi_transfer_data(SCSIRequest *sreq, uint32_t len)
518 {
519     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(sreq->bus->qbus.parent);
520     vscsi_req *req = sreq->hba_private;
521     uint8_t *buf;
522     int rc = 0;
523 
524     DPRINTF("VSCSI: SCSI xfer complete tag=0x%x len=0x%x, req=%p\n",
525             sreq->tag, len, req);
526     if (req == NULL) {
527         fprintf(stderr, "VSCSI: Can't find request for tag 0x%x\n", sreq->tag);
528         return;
529     }
530 
531     if (len) {
532         buf = scsi_req_get_buf(sreq);
533         rc = vscsi_srp_transfer_data(s, req, req->writing, buf, len);
534     }
535     if (rc < 0) {
536         fprintf(stderr, "VSCSI: RDMA error rc=%d!\n", rc);
537         vscsi_makeup_sense(s, req, HARDWARE_ERROR, 0, 0);
538         scsi_req_abort(req->sreq, CHECK_CONDITION);
539         return;
540     }
541 
542     /* Start next chunk */
543     req->data_len -= rc;
544     scsi_req_continue(sreq);
545 }
546 
547 /* Callback to indicate that the SCSI layer has completed a transfer.  */
548 static void vscsi_command_complete(SCSIRequest *sreq, uint32_t status, size_t resid)
549 {
550     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(sreq->bus->qbus.parent);
551     vscsi_req *req = sreq->hba_private;
552     int32_t res_in = 0, res_out = 0;
553 
554     DPRINTF("VSCSI: SCSI cmd complete, tag=0x%x status=0x%x, req=%p\n",
555             sreq->tag, status, req);
556     if (req == NULL) {
557         fprintf(stderr, "VSCSI: Can't find request for tag 0x%x\n", sreq->tag);
558         return;
559     }
560 
561     if (status == CHECK_CONDITION) {
562         req->senselen = scsi_req_get_sense(req->sreq, req->sense,
563                                            sizeof(req->sense));
564         DPRINTF("VSCSI: Sense data, %d bytes:\n", req->senselen);
565         DPRINTF("       %02x  %02x  %02x  %02x  %02x  %02x  %02x  %02x\n",
566                 req->sense[0], req->sense[1], req->sense[2], req->sense[3],
567                 req->sense[4], req->sense[5], req->sense[6], req->sense[7]);
568         DPRINTF("       %02x  %02x  %02x  %02x  %02x  %02x  %02x  %02x\n",
569                 req->sense[8], req->sense[9], req->sense[10], req->sense[11],
570                 req->sense[12], req->sense[13], req->sense[14], req->sense[15]);
571     }
572 
573     DPRINTF("VSCSI: Command complete err=%d\n", status);
574     if (status == 0) {
575         /* We handle overflows, not underflows for normal commands,
576          * but hopefully nobody cares
577          */
578         if (req->writing) {
579             res_out = req->data_len;
580         } else {
581             res_in = req->data_len;
582         }
583     }
584     vscsi_send_rsp(s, req, status, res_in, res_out);
585     vscsi_put_req(req);
586 }
587 
588 static void vscsi_request_cancelled(SCSIRequest *sreq)
589 {
590     vscsi_req *req = sreq->hba_private;
591 
592     vscsi_put_req(req);
593 }
594 
595 static const VMStateDescription vmstate_spapr_vscsi_req = {
596     .name = "spapr_vscsi_req",
597     .version_id = 1,
598     .minimum_version_id = 1,
599     .minimum_version_id_old = 1,
600     .fields      = (VMStateField []) {
601         VMSTATE_BUFFER(crq.raw, vscsi_req),
602         VMSTATE_BUFFER(iu.srp.reserved, vscsi_req),
603         VMSTATE_UINT32(qtag, vscsi_req),
604         VMSTATE_BOOL(active, vscsi_req),
605         VMSTATE_UINT32(data_len, vscsi_req),
606         VMSTATE_BOOL(writing, vscsi_req),
607         VMSTATE_UINT32(senselen, vscsi_req),
608         VMSTATE_BUFFER(sense, vscsi_req),
609         VMSTATE_UINT8(dma_fmt, vscsi_req),
610         VMSTATE_UINT16(local_desc, vscsi_req),
611         VMSTATE_UINT16(total_desc, vscsi_req),
612         VMSTATE_UINT16(cdb_offset, vscsi_req),
613       /*Restart SCSI request from the beginning for now */
614       /*VMSTATE_UINT16(cur_desc_num, vscsi_req),
615         VMSTATE_UINT16(cur_desc_offset, vscsi_req),*/
616         VMSTATE_END_OF_LIST()
617     },
618 };
619 
620 static void vscsi_save_request(QEMUFile *f, SCSIRequest *sreq)
621 {
622     vscsi_req *req = sreq->hba_private;
623     assert(req->active);
624 
625     vmstate_save_state(f, &vmstate_spapr_vscsi_req, req);
626 
627     DPRINTF("VSCSI: saving tag=%u, current desc#%d, offset=%x\n",
628             req->qtag, req->cur_desc_num, req->cur_desc_offset);
629 }
630 
631 static void *vscsi_load_request(QEMUFile *f, SCSIRequest *sreq)
632 {
633     SCSIBus *bus = sreq->bus;
634     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(bus->qbus.parent);
635     vscsi_req *req;
636     int rc;
637 
638     assert(sreq->tag < VSCSI_REQ_LIMIT);
639     req = &s->reqs[sreq->tag];
640     assert(!req->active);
641 
642     memset(req, 0, sizeof(*req));
643     rc = vmstate_load_state(f, &vmstate_spapr_vscsi_req, req, 1);
644     if (rc) {
645         fprintf(stderr, "VSCSI: failed loading request tag#%u\n", sreq->tag);
646         return NULL;
647     }
648     assert(req->active);
649 
650     req->sreq = scsi_req_ref(sreq);
651 
652     DPRINTF("VSCSI: restoring tag=%u, current desc#%d, offset=%x\n",
653             req->qtag, req->cur_desc_num, req->cur_desc_offset);
654 
655     return req;
656 }
657 
658 static void vscsi_process_login(VSCSIState *s, vscsi_req *req)
659 {
660     union viosrp_iu *iu = &req->iu;
661     struct srp_login_rsp *rsp = &iu->srp.login_rsp;
662     uint64_t tag = iu->srp.rsp.tag;
663 
664     DPRINTF("VSCSI: Got login, sendin response !\n");
665 
666     /* TODO handle case that requested size is wrong and
667      * buffer format is wrong
668      */
669     memset(iu, 0, sizeof(struct srp_login_rsp));
670     rsp->opcode = SRP_LOGIN_RSP;
671     /* Don't advertise quite as many request as we support to
672      * keep room for management stuff etc...
673      */
674     rsp->req_lim_delta = cpu_to_be32(VSCSI_REQ_LIMIT-2);
675     rsp->tag = tag;
676     rsp->max_it_iu_len = cpu_to_be32(sizeof(union srp_iu));
677     rsp->max_ti_iu_len = cpu_to_be32(sizeof(union srp_iu));
678     /* direct and indirect */
679     rsp->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT);
680 
681     vscsi_send_iu(s, req, sizeof(*rsp), VIOSRP_SRP_FORMAT);
682 }
683 
684 static void vscsi_inquiry_no_target(VSCSIState *s, vscsi_req *req)
685 {
686     uint8_t *cdb = req->iu.srp.cmd.cdb;
687     uint8_t resp_data[36];
688     int rc, len, alen;
689 
690     /* We dont do EVPD. Also check that page_code is 0 */
691     if ((cdb[1] & 0x01) || (cdb[1] & 0x01) || cdb[2] != 0) {
692         /* Send INVALID FIELD IN CDB */
693         vscsi_makeup_sense(s, req, ILLEGAL_REQUEST, 0x24, 0);
694         vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
695         return;
696     }
697     alen = cdb[3];
698     alen = (alen << 8) | cdb[4];
699     len = MIN(alen, 36);
700 
701     /* Fake up inquiry using PQ=3 */
702     memset(resp_data, 0, 36);
703     resp_data[0] = 0x7f;   /* Not capable of supporting a device here */
704     resp_data[2] = 0x06;   /* SPS-4 */
705     resp_data[3] = 0x02;   /* Resp data format */
706     resp_data[4] = 36 - 5; /* Additional length */
707     resp_data[7] = 0x10;   /* Sync transfers */
708     memcpy(&resp_data[16], "QEMU EMPTY      ", 16);
709     memcpy(&resp_data[8], "QEMU    ", 8);
710 
711     req->writing = 0;
712     vscsi_preprocess_desc(req);
713     rc = vscsi_srp_transfer_data(s, req, 0, resp_data, len);
714     if (rc < 0) {
715         vscsi_makeup_sense(s, req, HARDWARE_ERROR, 0, 0);
716         vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
717     } else {
718         vscsi_send_rsp(s, req, 0, 36 - rc, 0);
719     }
720 }
721 
722 static int vscsi_queue_cmd(VSCSIState *s, vscsi_req *req)
723 {
724     union srp_iu *srp = &req->iu.srp;
725     SCSIDevice *sdev;
726     int n, lun;
727 
728     sdev = vscsi_device_find(&s->bus, be64_to_cpu(srp->cmd.lun), &lun);
729     if (!sdev) {
730         DPRINTF("VSCSI: Command for lun %08" PRIx64 " with no drive\n",
731                 be64_to_cpu(srp->cmd.lun));
732         if (srp->cmd.cdb[0] == INQUIRY) {
733             vscsi_inquiry_no_target(s, req);
734         } else {
735             vscsi_makeup_sense(s, req, ILLEGAL_REQUEST, 0x24, 0x00);
736             vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
737         } return 1;
738     }
739 
740     req->sreq = scsi_req_new(sdev, req->qtag, lun, srp->cmd.cdb, req);
741     n = scsi_req_enqueue(req->sreq);
742 
743     DPRINTF("VSCSI: Queued command tag 0x%x CMD 0x%x LUN %d ret: %d\n",
744             req->qtag, srp->cmd.cdb[0], lun, n);
745 
746     if (n) {
747         /* Transfer direction must be set before preprocessing the
748          * descriptors
749          */
750         req->writing = (n < 1);
751 
752         /* Preprocess RDMA descriptors */
753         vscsi_preprocess_desc(req);
754 
755         /* Get transfer direction and initiate transfer */
756         if (n > 0) {
757             req->data_len = n;
758         } else if (n < 0) {
759             req->data_len = -n;
760         }
761         scsi_req_continue(req->sreq);
762     }
763     /* Don't touch req here, it may have been recycled already */
764 
765     return 0;
766 }
767 
768 static int vscsi_process_tsk_mgmt(VSCSIState *s, vscsi_req *req)
769 {
770     union viosrp_iu *iu = &req->iu;
771     vscsi_req *tmpreq;
772     int i, lun = 0, resp = SRP_TSK_MGMT_COMPLETE;
773     SCSIDevice *d;
774     uint64_t tag = iu->srp.rsp.tag;
775     uint8_t sol_not = iu->srp.cmd.sol_not;
776 
777     fprintf(stderr, "vscsi_process_tsk_mgmt %02x\n",
778             iu->srp.tsk_mgmt.tsk_mgmt_func);
779 
780     d = vscsi_device_find(&s->bus, be64_to_cpu(req->iu.srp.tsk_mgmt.lun), &lun);
781     if (!d) {
782         resp = SRP_TSK_MGMT_FIELDS_INVALID;
783     } else {
784         switch (iu->srp.tsk_mgmt.tsk_mgmt_func) {
785         case SRP_TSK_ABORT_TASK:
786             if (d->lun != lun) {
787                 resp = SRP_TSK_MGMT_FIELDS_INVALID;
788                 break;
789             }
790 
791             tmpreq = vscsi_find_req(s, req->iu.srp.tsk_mgmt.task_tag);
792             if (tmpreq && tmpreq->sreq) {
793                 assert(tmpreq->sreq->hba_private);
794                 scsi_req_cancel(tmpreq->sreq);
795             }
796             break;
797 
798         case SRP_TSK_LUN_RESET:
799             if (d->lun != lun) {
800                 resp = SRP_TSK_MGMT_FIELDS_INVALID;
801                 break;
802             }
803 
804             qdev_reset_all(&d->qdev);
805             break;
806 
807         case SRP_TSK_ABORT_TASK_SET:
808         case SRP_TSK_CLEAR_TASK_SET:
809             if (d->lun != lun) {
810                 resp = SRP_TSK_MGMT_FIELDS_INVALID;
811                 break;
812             }
813 
814             for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
815                 tmpreq = &s->reqs[i];
816                 if (tmpreq->iu.srp.cmd.lun != req->iu.srp.tsk_mgmt.lun) {
817                     continue;
818                 }
819                 if (!tmpreq->active || !tmpreq->sreq) {
820                     continue;
821                 }
822                 assert(tmpreq->sreq->hba_private);
823                 scsi_req_cancel(tmpreq->sreq);
824             }
825             break;
826 
827         case SRP_TSK_CLEAR_ACA:
828             resp = SRP_TSK_MGMT_NOT_SUPPORTED;
829             break;
830 
831         default:
832             resp = SRP_TSK_MGMT_FIELDS_INVALID;
833             break;
834         }
835     }
836 
837     /* Compose the response here as  */
838     memset(iu, 0, sizeof(struct srp_rsp) + 4);
839     iu->srp.rsp.opcode = SRP_RSP;
840     iu->srp.rsp.req_lim_delta = cpu_to_be32(1);
841     iu->srp.rsp.tag = tag;
842     iu->srp.rsp.flags |= SRP_RSP_FLAG_RSPVALID;
843     iu->srp.rsp.resp_data_len = cpu_to_be32(4);
844     if (resp) {
845         iu->srp.rsp.sol_not = (sol_not & 0x04) >> 2;
846     } else {
847         iu->srp.rsp.sol_not = (sol_not & 0x02) >> 1;
848     }
849 
850     iu->srp.rsp.status = GOOD;
851     iu->srp.rsp.data[3] = resp;
852 
853     vscsi_send_iu(s, req, sizeof(iu->srp.rsp) + 4, VIOSRP_SRP_FORMAT);
854 
855     return 1;
856 }
857 
858 static int vscsi_handle_srp_req(VSCSIState *s, vscsi_req *req)
859 {
860     union srp_iu *srp = &req->iu.srp;
861     int done = 1;
862     uint8_t opcode = srp->rsp.opcode;
863 
864     switch (opcode) {
865     case SRP_LOGIN_REQ:
866         vscsi_process_login(s, req);
867         break;
868     case SRP_TSK_MGMT:
869         done = vscsi_process_tsk_mgmt(s, req);
870         break;
871     case SRP_CMD:
872         done = vscsi_queue_cmd(s, req);
873         break;
874     case SRP_LOGIN_RSP:
875     case SRP_I_LOGOUT:
876     case SRP_T_LOGOUT:
877     case SRP_RSP:
878     case SRP_CRED_REQ:
879     case SRP_CRED_RSP:
880     case SRP_AER_REQ:
881     case SRP_AER_RSP:
882         fprintf(stderr, "VSCSI: Unsupported opcode %02x\n", opcode);
883         break;
884     default:
885         fprintf(stderr, "VSCSI: Unknown type %02x\n", opcode);
886     }
887 
888     return done;
889 }
890 
891 static int vscsi_send_adapter_info(VSCSIState *s, vscsi_req *req)
892 {
893     struct viosrp_adapter_info *sinfo;
894     struct mad_adapter_info_data info;
895     int rc;
896 
897     sinfo = &req->iu.mad.adapter_info;
898 
899 #if 0 /* What for ? */
900     rc = spapr_vio_dma_read(&s->vdev, be64_to_cpu(sinfo->buffer),
901                             &info, be16_to_cpu(sinfo->common.length));
902     if (rc) {
903         fprintf(stderr, "vscsi_send_adapter_info: DMA read failure !\n");
904     }
905 #endif
906     memset(&info, 0, sizeof(info));
907     strcpy(info.srp_version, SRP_VERSION);
908     memcpy(info.partition_name, "qemu", sizeof("qemu"));
909     info.partition_number = cpu_to_be32(0);
910     info.mad_version = cpu_to_be32(1);
911     info.os_type = cpu_to_be32(2);
912     info.port_max_txu[0] = cpu_to_be32(VSCSI_MAX_SECTORS << 9);
913 
914     rc = spapr_vio_dma_write(&s->vdev, be64_to_cpu(sinfo->buffer),
915                              &info, be16_to_cpu(sinfo->common.length));
916     if (rc)  {
917         fprintf(stderr, "vscsi_send_adapter_info: DMA write failure !\n");
918     }
919 
920     sinfo->common.status = rc ? cpu_to_be32(1) : 0;
921 
922     return vscsi_send_iu(s, req, sizeof(*sinfo), VIOSRP_MAD_FORMAT);
923 }
924 
925 static int vscsi_send_capabilities(VSCSIState *s, vscsi_req *req)
926 {
927     struct viosrp_capabilities *vcap;
928     struct capabilities cap = { };
929     uint16_t len, req_len;
930     uint64_t buffer;
931     int rc;
932 
933     vcap = &req->iu.mad.capabilities;
934     req_len = len = be16_to_cpu(vcap->common.length);
935     buffer = be64_to_cpu(vcap->buffer);
936     if (len > sizeof(cap)) {
937         fprintf(stderr, "vscsi_send_capabilities: capabilities size mismatch !\n");
938 
939         /*
940          * Just read and populate the structure that is known.
941          * Zero rest of the structure.
942          */
943         len = sizeof(cap);
944     }
945     rc = spapr_vio_dma_read(&s->vdev, buffer, &cap, len);
946     if (rc)  {
947         fprintf(stderr, "vscsi_send_capabilities: DMA read failure !\n");
948     }
949 
950     /*
951      * Current implementation does not suppport any migration or
952      * reservation capabilities. Construct the response telling the
953      * guest not to use them.
954      */
955     cap.flags = 0;
956     cap.migration.ecl = 0;
957     cap.reserve.type = 0;
958     cap.migration.common.server_support = 0;
959     cap.reserve.common.server_support = 0;
960 
961     rc = spapr_vio_dma_write(&s->vdev, buffer, &cap, len);
962     if (rc)  {
963         fprintf(stderr, "vscsi_send_capabilities: DMA write failure !\n");
964     }
965     if (req_len > len) {
966         /*
967          * Being paranoid and lets not worry about the error code
968          * here. Actual write of the cap is done above.
969          */
970         spapr_vio_dma_set(&s->vdev, (buffer + len), 0, (req_len - len));
971     }
972     vcap->common.status = rc ? cpu_to_be32(1) : 0;
973     return vscsi_send_iu(s, req, sizeof(*vcap), VIOSRP_MAD_FORMAT);
974 }
975 
976 static int vscsi_handle_mad_req(VSCSIState *s, vscsi_req *req)
977 {
978     union mad_iu *mad = &req->iu.mad;
979     bool request_handled = false;
980     uint64_t retlen = 0;
981 
982     switch (be32_to_cpu(mad->empty_iu.common.type)) {
983     case VIOSRP_EMPTY_IU_TYPE:
984         fprintf(stderr, "Unsupported EMPTY MAD IU\n");
985         retlen = sizeof(mad->empty_iu);
986         break;
987     case VIOSRP_ERROR_LOG_TYPE:
988         fprintf(stderr, "Unsupported ERROR LOG MAD IU\n");
989         retlen = sizeof(mad->error_log);
990         break;
991     case VIOSRP_ADAPTER_INFO_TYPE:
992         vscsi_send_adapter_info(s, req);
993         request_handled = true;
994         break;
995     case VIOSRP_HOST_CONFIG_TYPE:
996         retlen = sizeof(mad->host_config);
997         break;
998     case VIOSRP_CAPABILITIES_TYPE:
999         vscsi_send_capabilities(s, req);
1000         request_handled = true;
1001         break;
1002     default:
1003         fprintf(stderr, "VSCSI: Unknown MAD type %02x\n",
1004                 be32_to_cpu(mad->empty_iu.common.type));
1005         /*
1006          * PAPR+ says that "The length field is set to the length
1007          * of the data structure(s) used in the command".
1008          * As we did not recognize the request type, put zero there.
1009          */
1010         retlen = 0;
1011     }
1012 
1013     if (!request_handled) {
1014         mad->empty_iu.common.status = cpu_to_be16(VIOSRP_MAD_NOT_SUPPORTED);
1015         vscsi_send_iu(s, req, retlen, VIOSRP_MAD_FORMAT);
1016     }
1017 
1018     return 1;
1019 }
1020 
1021 static void vscsi_got_payload(VSCSIState *s, vscsi_crq *crq)
1022 {
1023     vscsi_req *req;
1024     int done;
1025 
1026     req = vscsi_get_req(s);
1027     if (req == NULL) {
1028         fprintf(stderr, "VSCSI: Failed to get a request !\n");
1029         return;
1030     }
1031 
1032     /* We only support a limited number of descriptors, we know
1033      * the ibmvscsi driver uses up to 10 max, so it should fit
1034      * in our 256 bytes IUs. If not we'll have to increase the size
1035      * of the structure.
1036      */
1037     if (crq->s.IU_length > sizeof(union viosrp_iu)) {
1038         fprintf(stderr, "VSCSI: SRP IU too long (%d bytes) !\n",
1039                 crq->s.IU_length);
1040         vscsi_put_req(req);
1041         return;
1042     }
1043 
1044     /* XXX Handle failure differently ? */
1045     if (spapr_vio_dma_read(&s->vdev, crq->s.IU_data_ptr, &req->iu,
1046                            crq->s.IU_length)) {
1047         fprintf(stderr, "vscsi_got_payload: DMA read failure !\n");
1048         vscsi_put_req(req);
1049         return;
1050     }
1051     memcpy(&req->crq, crq, sizeof(vscsi_crq));
1052 
1053     if (crq->s.format == VIOSRP_MAD_FORMAT) {
1054         done = vscsi_handle_mad_req(s, req);
1055     } else {
1056         done = vscsi_handle_srp_req(s, req);
1057     }
1058 
1059     if (done) {
1060         vscsi_put_req(req);
1061     }
1062 }
1063 
1064 
1065 static int vscsi_do_crq(struct VIOsPAPRDevice *dev, uint8_t *crq_data)
1066 {
1067     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(dev);
1068     vscsi_crq crq;
1069 
1070     memcpy(crq.raw, crq_data, 16);
1071     crq.s.timeout = be16_to_cpu(crq.s.timeout);
1072     crq.s.IU_length = be16_to_cpu(crq.s.IU_length);
1073     crq.s.IU_data_ptr = be64_to_cpu(crq.s.IU_data_ptr);
1074 
1075     DPRINTF("VSCSI: do_crq %02x %02x ...\n", crq.raw[0], crq.raw[1]);
1076 
1077     switch (crq.s.valid) {
1078     case 0xc0: /* Init command/response */
1079 
1080         /* Respond to initialization request */
1081         if (crq.s.format == 0x01) {
1082             memset(crq.raw, 0, 16);
1083             crq.s.valid = 0xc0;
1084             crq.s.format = 0x02;
1085             spapr_vio_send_crq(dev, crq.raw);
1086         }
1087 
1088         /* Note that in hotplug cases, we might get a 0x02
1089          * as a result of us emitting the init request
1090          */
1091 
1092         break;
1093     case 0xff: /* Link event */
1094 
1095         /* Not handled for now */
1096 
1097         break;
1098     case 0x80: /* Payloads */
1099         switch (crq.s.format) {
1100         case VIOSRP_SRP_FORMAT: /* AKA VSCSI request */
1101         case VIOSRP_MAD_FORMAT: /* AKA VSCSI response */
1102             vscsi_got_payload(s, &crq);
1103             break;
1104         case VIOSRP_OS400_FORMAT:
1105         case VIOSRP_AIX_FORMAT:
1106         case VIOSRP_LINUX_FORMAT:
1107         case VIOSRP_INLINE_FORMAT:
1108             fprintf(stderr, "vscsi_do_srq: Unsupported payload format %02x\n",
1109                     crq.s.format);
1110             break;
1111         default:
1112             fprintf(stderr, "vscsi_do_srq: Unknown payload format %02x\n",
1113                     crq.s.format);
1114         }
1115         break;
1116     default:
1117         fprintf(stderr, "vscsi_do_crq: unknown CRQ %02x %02x ...\n",
1118                 crq.raw[0], crq.raw[1]);
1119     };
1120 
1121     return 0;
1122 }
1123 
1124 static const struct SCSIBusInfo vscsi_scsi_info = {
1125     .tcq = true,
1126     .max_channel = 7, /* logical unit addressing format */
1127     .max_target = 63,
1128     .max_lun = 31,
1129 
1130     .transfer_data = vscsi_transfer_data,
1131     .complete = vscsi_command_complete,
1132     .cancel = vscsi_request_cancelled,
1133     .save_request = vscsi_save_request,
1134     .load_request = vscsi_load_request,
1135 };
1136 
1137 static void spapr_vscsi_reset(VIOsPAPRDevice *dev)
1138 {
1139     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(dev);
1140     int i;
1141 
1142     memset(s->reqs, 0, sizeof(s->reqs));
1143     for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
1144         s->reqs[i].qtag = i;
1145     }
1146 }
1147 
1148 static int spapr_vscsi_init(VIOsPAPRDevice *dev)
1149 {
1150     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(dev);
1151     Error *err = NULL;
1152 
1153     dev->crq.SendFunc = vscsi_do_crq;
1154 
1155     scsi_bus_new(&s->bus, sizeof(s->bus), DEVICE(dev),
1156                  &vscsi_scsi_info, NULL);
1157     if (!dev->qdev.hotplugged) {
1158         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
1159         if (err != NULL) {
1160             error_free(err);
1161             return -1;
1162         }
1163     }
1164 
1165     return 0;
1166 }
1167 
1168 void spapr_vscsi_create(VIOsPAPRBus *bus)
1169 {
1170     DeviceState *dev;
1171 
1172     dev = qdev_create(&bus->bus, "spapr-vscsi");
1173 
1174     qdev_init_nofail(dev);
1175 }
1176 
1177 static int spapr_vscsi_devnode(VIOsPAPRDevice *dev, void *fdt, int node_off)
1178 {
1179     int ret;
1180 
1181     ret = fdt_setprop_cell(fdt, node_off, "#address-cells", 2);
1182     if (ret < 0) {
1183         return ret;
1184     }
1185 
1186     ret = fdt_setprop_cell(fdt, node_off, "#size-cells", 0);
1187     if (ret < 0) {
1188         return ret;
1189     }
1190 
1191     return 0;
1192 }
1193 
1194 static Property spapr_vscsi_properties[] = {
1195     DEFINE_SPAPR_PROPERTIES(VSCSIState, vdev),
1196     DEFINE_PROP_END_OF_LIST(),
1197 };
1198 
1199 static const VMStateDescription vmstate_spapr_vscsi = {
1200     .name = "spapr_vscsi",
1201     .version_id = 1,
1202     .minimum_version_id = 1,
1203     .minimum_version_id_old = 1,
1204     .fields      = (VMStateField []) {
1205         VMSTATE_SPAPR_VIO(vdev, VSCSIState),
1206         /* VSCSI state */
1207         /* ???? */
1208 
1209         VMSTATE_END_OF_LIST()
1210     },
1211 };
1212 
1213 static void spapr_vscsi_class_init(ObjectClass *klass, void *data)
1214 {
1215     DeviceClass *dc = DEVICE_CLASS(klass);
1216     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
1217 
1218     k->init = spapr_vscsi_init;
1219     k->reset = spapr_vscsi_reset;
1220     k->devnode = spapr_vscsi_devnode;
1221     k->dt_name = "v-scsi";
1222     k->dt_type = "vscsi";
1223     k->dt_compatible = "IBM,v-scsi";
1224     k->signal_mask = 0x00000001;
1225     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1226     dc->props = spapr_vscsi_properties;
1227     k->rtce_window_size = 0x10000000;
1228     dc->vmsd = &vmstate_spapr_vscsi;
1229 }
1230 
1231 static const TypeInfo spapr_vscsi_info = {
1232     .name          = TYPE_VIO_SPAPR_VSCSI_DEVICE,
1233     .parent        = TYPE_VIO_SPAPR_DEVICE,
1234     .instance_size = sizeof(VSCSIState),
1235     .class_init    = spapr_vscsi_class_init,
1236 };
1237 
1238 static void spapr_vscsi_register_types(void)
1239 {
1240     type_register_static(&spapr_vscsi_info);
1241 }
1242 
1243 type_init(spapr_vscsi_register_types)
1244