1 /*
2 * Virtio-SCSI implementation for s390 machine loader for qemu
3 *
4 * Copyright 2015 IBM Corp.
5 * Author: Eugene "jno" Dvurechenski <jno@linux.vnet.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 "libc.h"
13 #include "s390-ccw.h"
14 #include "virtio.h"
15 #include "scsi.h"
16 #include "virtio-scsi.h"
17 #include "s390-time.h"
18 #include "helper.h"
19
20 static ScsiDevice default_scsi_device;
21 static VirtioScsiCmdReq req;
22 static VirtioScsiCmdResp resp;
23
24 static uint8_t scsi_inquiry_std_response[256];
25 static ScsiInquiryEvpdPages scsi_inquiry_evpd_pages_response;
26 static ScsiInquiryEvpdBl scsi_inquiry_evpd_bl_response;
27
vs_assert(bool term,const char ** msgs)28 static inline void vs_assert(bool term, const char **msgs)
29 {
30 if (!term) {
31 int i = 0;
32
33 sclp_print("\n! ");
34 while (msgs[i]) {
35 sclp_print(msgs[i++]);
36 }
37 panic(" !\n");
38 }
39 }
40
virtio_scsi_verify_response(VirtioScsiCmdResp * resp,const char * title)41 static void virtio_scsi_verify_response(VirtioScsiCmdResp *resp,
42 const char *title)
43 {
44 const char *mr[] = {
45 title, ": response ", virtio_scsi_response_msg(resp), 0
46 };
47 const char *ms[] = {
48 title,
49 CDB_STATUS_VALID(resp->status) ? ": " : ": invalid ",
50 scsi_cdb_status_msg(resp->status),
51 resp->status == CDB_STATUS_CHECK_CONDITION ? " " : 0,
52 resp->sense_len ? scsi_cdb_asc_msg(resp->sense)
53 : "no sense data",
54 scsi_sense_response(resp->sense) == 0x70 ? ", sure" : "?",
55 0
56 };
57
58 vs_assert(resp->response == VIRTIO_SCSI_S_OK, mr);
59 vs_assert(resp->status == CDB_STATUS_GOOD, ms);
60 }
61
prepare_request(VDev * vdev,const void * cdb,int cdb_size,void * data,uint32_t data_size)62 static void prepare_request(VDev *vdev, const void *cdb, int cdb_size,
63 void *data, uint32_t data_size)
64 {
65 const ScsiDevice *sdev = vdev->scsi_device;
66
67 memset(&req, 0, sizeof(req));
68 req.lun = make_lun(sdev->channel, sdev->target, sdev->lun);
69 memcpy(&req.cdb, cdb, cdb_size);
70
71 memset(&resp, 0, sizeof(resp));
72 resp.status = 0xff; /* set invalid */
73 resp.response = 0xff; /* */
74
75 if (data && data_size) {
76 memset(data, 0, data_size);
77 }
78 }
79
vs_io_assert(bool term,const char * msg)80 static inline void vs_io_assert(bool term, const char *msg)
81 {
82 if (!term) {
83 virtio_scsi_verify_response(&resp, msg);
84 }
85 }
86
vs_run(const char * title,VirtioCmd * cmd,VDev * vdev,const void * cdb,int cdb_size,void * data,uint32_t data_size)87 static void vs_run(const char *title, VirtioCmd *cmd, VDev *vdev,
88 const void *cdb, int cdb_size,
89 void *data, uint32_t data_size)
90 {
91 prepare_request(vdev, cdb, cdb_size, data, data_size);
92 vs_io_assert(virtio_run(vdev, VR_REQUEST, cmd) == 0, title);
93 }
94
95 /* SCSI protocol implementation routines */
96
scsi_inquiry(VDev * vdev,uint8_t evpd,uint8_t page,void * data,uint32_t data_size)97 static bool scsi_inquiry(VDev *vdev, uint8_t evpd, uint8_t page,
98 void *data, uint32_t data_size)
99 {
100 ScsiCdbInquiry cdb = {
101 .command = 0x12,
102 .b1 = evpd,
103 .b2 = page,
104 .alloc_len = data_size < 65535 ? data_size : 65535,
105 };
106 VirtioCmd inquiry[] = {
107 { &req, sizeof(req), VRING_DESC_F_NEXT },
108 { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
109 { data, data_size, VRING_DESC_F_WRITE },
110 };
111
112 vs_run("inquiry", inquiry, vdev, &cdb, sizeof(cdb), data, data_size);
113
114 return virtio_scsi_response_ok(&resp);
115 }
116
scsi_test_unit_ready(VDev * vdev)117 static bool scsi_test_unit_ready(VDev *vdev)
118 {
119 ScsiCdbTestUnitReady cdb = {
120 .command = 0x00,
121 };
122 VirtioCmd test_unit_ready[] = {
123 { &req, sizeof(req), VRING_DESC_F_NEXT },
124 { &resp, sizeof(resp), VRING_DESC_F_WRITE },
125 };
126
127 prepare_request(vdev, &cdb, sizeof(cdb), 0, 0);
128 virtio_run(vdev, VR_REQUEST, test_unit_ready); /* ignore errors here */
129
130 return virtio_scsi_response_ok(&resp);
131 }
132
scsi_report_luns(VDev * vdev,void * data,uint32_t data_size)133 static bool scsi_report_luns(VDev *vdev, void *data, uint32_t data_size)
134 {
135 ScsiCdbReportLuns cdb = {
136 .command = 0xa0,
137 .select_report = 0x02, /* REPORT ALL */
138 .alloc_len = data_size,
139 };
140 VirtioCmd report_luns[] = {
141 { &req, sizeof(req), VRING_DESC_F_NEXT },
142 { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
143 { data, data_size, VRING_DESC_F_WRITE },
144 };
145
146 vs_run("report luns", report_luns,
147 vdev, &cdb, sizeof(cdb), data, data_size);
148
149 return virtio_scsi_response_ok(&resp);
150 }
151
scsi_read_10(VDev * vdev,unsigned long sector,int sectors,void * data,unsigned int data_size)152 static bool scsi_read_10(VDev *vdev,
153 unsigned long sector, int sectors, void *data,
154 unsigned int data_size)
155 {
156 ScsiCdbRead10 cdb = {
157 .command = 0x28,
158 .lba = sector,
159 .xfer_length = sectors,
160 };
161 VirtioCmd read_10[] = {
162 { &req, sizeof(req), VRING_DESC_F_NEXT },
163 { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
164 { data, data_size, VRING_DESC_F_WRITE },
165 };
166
167 debug_print_int("read_10 sector", sector);
168 debug_print_int("read_10 sectors", sectors);
169
170 vs_run("read(10)", read_10, vdev, &cdb, sizeof(cdb), data, data_size);
171
172 return virtio_scsi_response_ok(&resp);
173 }
174
scsi_read_capacity(VDev * vdev,void * data,uint32_t data_size)175 static bool scsi_read_capacity(VDev *vdev,
176 void *data, uint32_t data_size)
177 {
178 ScsiCdbReadCapacity16 cdb = {
179 .command = 0x9e, /* SERVICE_ACTION_IN_16 */
180 .service_action = 0x10, /* SA_READ_CAPACITY */
181 .alloc_len = data_size,
182 };
183 VirtioCmd read_capacity_16[] = {
184 { &req, sizeof(req), VRING_DESC_F_NEXT },
185 { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
186 { data, data_size, VRING_DESC_F_WRITE },
187 };
188
189 vs_run("read capacity", read_capacity_16,
190 vdev, &cdb, sizeof(cdb), data, data_size);
191
192 return virtio_scsi_response_ok(&resp);
193 }
194
195 /* virtio-scsi routines */
196
197 /*
198 * Tries to locate a SCSI device and adds the information for the found
199 * device to the vdev->scsi_device structure.
200 * Returns 0 if SCSI device could be located, or a error code < 0 otherwise
201 */
virtio_scsi_locate_device(VDev * vdev)202 static int virtio_scsi_locate_device(VDev *vdev)
203 {
204 const uint16_t channel = 0; /* again, it's what QEMU does */
205 uint16_t target;
206 static uint8_t data[16 + 8 * 63];
207 ScsiLunReport *r = (void *) data;
208 ScsiDevice *sdev = vdev->scsi_device;
209 int i, luns;
210
211 /* QEMU has hardcoded channel #0 in many places.
212 * If this hardcoded value is ever changed, we'll need to add code for
213 * vdev->config.scsi.max_channel != 0 here.
214 */
215 debug_print_int("config.scsi.max_channel", vdev->config.scsi.max_channel);
216 debug_print_int("config.scsi.max_target ", vdev->config.scsi.max_target);
217 debug_print_int("config.scsi.max_lun ", vdev->config.scsi.max_lun);
218 debug_print_int("config.scsi.max_sectors", vdev->config.scsi.max_sectors);
219
220 if (vdev->scsi_device_selected) {
221 sdev->channel = vdev->selected_scsi_device.channel;
222 sdev->target = vdev->selected_scsi_device.target;
223 sdev->lun = vdev->selected_scsi_device.lun;
224
225 IPL_check(sdev->channel == 0, "non-zero channel requested");
226 IPL_check(sdev->target <= vdev->config.scsi.max_target, "target# high");
227 IPL_check(sdev->lun <= vdev->config.scsi.max_lun, "LUN# high");
228 return 0;
229 }
230
231 for (target = 0; target <= vdev->config.scsi.max_target; target++) {
232 sdev->channel = channel;
233 sdev->target = target;
234 sdev->lun = 0; /* LUN has to be 0 for REPORT LUNS */
235 if (!scsi_report_luns(vdev, data, sizeof(data))) {
236 if (resp.response == VIRTIO_SCSI_S_BAD_TARGET) {
237 continue;
238 }
239 print_int("target", target);
240 virtio_scsi_verify_response(&resp, "SCSI cannot report LUNs");
241 }
242 if (r->lun_list_len == 0) {
243 print_int("no LUNs for target", target);
244 continue;
245 }
246 luns = r->lun_list_len / 8;
247 debug_print_int("LUNs reported", luns);
248 if (luns == 1) {
249 /* There is no ",lun=#" arg for -device or ",lun=0" given.
250 * Hence, the only LUN reported.
251 * Usually, it's 0.
252 */
253 sdev->lun = r->lun[0].v16[0]; /* it's returned this way */
254 debug_print_int("Have to use LUN", sdev->lun);
255 return 0; /* we have to use this device */
256 }
257 for (i = 0; i < luns; i++) {
258 if (r->lun[i].v64) {
259 /* Look for non-zero LUN - we have where to choose from */
260 sdev->lun = r->lun[i].v16[0];
261 debug_print_int("Will use LUN", sdev->lun);
262 return 0; /* we have found a device */
263 }
264 }
265 }
266
267 sclp_print("Warning: Could not locate a usable virtio-scsi device\n");
268 return -ENODEV;
269 }
270
virtio_scsi_read_many(VDev * vdev,unsigned long sector,void * load_addr,int sec_num)271 int virtio_scsi_read_many(VDev *vdev,
272 unsigned long sector, void *load_addr, int sec_num)
273 {
274 int sector_count;
275 int f = vdev->blk_factor;
276 unsigned int data_size;
277 unsigned int max_transfer = MIN_NON_ZERO(vdev->config.scsi.max_sectors,
278 vdev->max_transfer);
279
280 do {
281 sector_count = MIN_NON_ZERO(sec_num, max_transfer);
282 data_size = sector_count * virtio_get_block_size() * f;
283 if (!scsi_read_10(vdev, sector * f, sector_count * f, load_addr,
284 data_size)) {
285 virtio_scsi_verify_response(&resp, "virtio-scsi:read_many");
286 }
287 load_addr += data_size;
288 sector += sector_count;
289 sec_num -= sector_count;
290 } while (sec_num > 0);
291
292 return 0;
293 }
294
virtio_scsi_inquiry_response_is_cdrom(void * data)295 static bool virtio_scsi_inquiry_response_is_cdrom(void *data)
296 {
297 const ScsiInquiryStd *response = data;
298 const int resp_data_fmt = response->b3 & 0x0f;
299 int i;
300
301 IPL_check(resp_data_fmt == 2, "Wrong INQUIRY response format");
302 if (resp_data_fmt != 2) {
303 return false; /* cannot decode */
304 }
305
306 if ((response->peripheral_qdt & 0x1f) == SCSI_INQ_RDT_CDROM) {
307 return true;
308 }
309
310 for (i = 0; i < sizeof(response->prod_id); i++) {
311 if (response->prod_id[i] != QEMU_CDROM_SIGNATURE[i]) {
312 return false;
313 }
314 }
315 return true;
316 }
317
scsi_parse_capacity_report(void * data,uint64_t * last_lba,uint32_t * lb_len)318 static void scsi_parse_capacity_report(void *data,
319 uint64_t *last_lba, uint32_t *lb_len)
320 {
321 ScsiReadCapacity16Data *p = data;
322
323 if (last_lba) {
324 *last_lba = p->ret_lba;
325 }
326
327 if (lb_len) {
328 *lb_len = p->lb_len;
329 }
330 }
331
virtio_scsi_setup(VDev * vdev)332 static int virtio_scsi_setup(VDev *vdev)
333 {
334 int retry_test_unit_ready = 3;
335 uint8_t data[256];
336 uint32_t data_size = sizeof(data);
337 ScsiInquiryEvpdPages *evpd = &scsi_inquiry_evpd_pages_response;
338 ScsiInquiryEvpdBl *evpd_bl = &scsi_inquiry_evpd_bl_response;
339 int i, ret;
340
341 vdev->scsi_device = &default_scsi_device;
342 ret = virtio_scsi_locate_device(vdev);
343 if (ret < 0) {
344 return ret;
345 }
346
347 /* We have to "ping" the device before it becomes readable */
348 while (!scsi_test_unit_ready(vdev)) {
349
350 if (!virtio_scsi_response_ok(&resp)) {
351 uint8_t code = resp.sense[0] & SCSI_SENSE_CODE_MASK;
352 uint8_t sense_key = resp.sense[2] & SCSI_SENSE_KEY_MASK;
353
354 IPL_assert(resp.sense_len != 0, "virtio-scsi:setup: no SENSE data");
355
356 IPL_assert(retry_test_unit_ready && code == 0x70 &&
357 sense_key == SCSI_SENSE_KEY_UNIT_ATTENTION,
358 "virtio-scsi:setup: cannot retry");
359
360 /* retry on CHECK_CONDITION/UNIT_ATTENTION as it
361 * may not designate a real error, but it may be
362 * a result of device reset, etc.
363 */
364 retry_test_unit_ready--;
365 sleep(1);
366 continue;
367 }
368
369 virtio_scsi_verify_response(&resp, "virtio-scsi:setup");
370 }
371
372 /* read and cache SCSI INQUIRY response */
373 if (!scsi_inquiry(vdev,
374 SCSI_INQUIRY_STANDARD,
375 SCSI_INQUIRY_STANDARD_NONE,
376 scsi_inquiry_std_response,
377 sizeof(scsi_inquiry_std_response))) {
378 virtio_scsi_verify_response(&resp, "virtio-scsi:setup:inquiry");
379 }
380
381 if (virtio_scsi_inquiry_response_is_cdrom(scsi_inquiry_std_response)) {
382 sclp_print("SCSI CD-ROM detected.\n");
383 vdev->is_cdrom = true;
384 vdev->scsi_block_size = VIRTIO_ISO_BLOCK_SIZE;
385 }
386
387 if (!scsi_inquiry(vdev,
388 SCSI_INQUIRY_EVPD,
389 SCSI_INQUIRY_EVPD_SUPPORTED_PAGES,
390 evpd,
391 sizeof(*evpd))) {
392 virtio_scsi_verify_response(&resp, "virtio-scsi:setup:supported_pages");
393 }
394
395 debug_print_int("EVPD length", evpd->page_length);
396
397 for (i = 0; i <= evpd->page_length; i++) {
398 debug_print_int("supported EVPD page", evpd->byte[i]);
399
400 if (evpd->byte[i] != SCSI_INQUIRY_EVPD_BLOCK_LIMITS) {
401 continue;
402 }
403
404 if (!scsi_inquiry(vdev,
405 SCSI_INQUIRY_EVPD,
406 SCSI_INQUIRY_EVPD_BLOCK_LIMITS,
407 evpd_bl,
408 sizeof(*evpd_bl))) {
409 virtio_scsi_verify_response(&resp, "virtio-scsi:setup:blocklimits");
410 }
411
412 debug_print_int("max transfer", evpd_bl->max_transfer);
413 vdev->max_transfer = evpd_bl->max_transfer;
414 }
415
416 /*
417 * The host sg driver will often be unhappy with particularly large
418 * I/Os that exceed the block iovec limits. Let's enforce something
419 * reasonable, despite what the device configuration tells us.
420 */
421
422 vdev->max_transfer = MIN_NON_ZERO(VIRTIO_SCSI_MAX_SECTORS,
423 vdev->max_transfer);
424
425 if (!scsi_read_capacity(vdev, data, data_size)) {
426 virtio_scsi_verify_response(&resp, "virtio-scsi:setup:read_capacity");
427 }
428 scsi_parse_capacity_report(data, &vdev->scsi_last_block,
429 (uint32_t *) &vdev->scsi_block_size);
430
431 return 0;
432 }
433
virtio_scsi_setup_device(SubChannelId schid)434 int virtio_scsi_setup_device(SubChannelId schid)
435 {
436 VDev *vdev = virtio_get_device();
437
438 vdev->schid = schid;
439 virtio_setup_ccw(vdev);
440
441 IPL_assert(vdev->config.scsi.sense_size == VIRTIO_SCSI_SENSE_SIZE,
442 "Config: sense size mismatch");
443 IPL_assert(vdev->config.scsi.cdb_size == VIRTIO_SCSI_CDB_SIZE,
444 "Config: CDB size mismatch");
445
446 sclp_print("Using virtio-scsi.\n");
447
448 return virtio_scsi_setup(vdev);
449 }
450