virtio-scsi.c (14286B)
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 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 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 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 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 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 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 } 116 117 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 } 132 133 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 } 151 152 static bool scsi_read_10(VDev *vdev, 153 ulong 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 } 174 175 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 */ 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 } 270 271 int virtio_scsi_read_many(VDev *vdev, 272 ulong 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 } 294 295 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 } 317 318 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 } 331 332 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 } 433 434 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 }