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