pc-bios/s390-ccw/virtio-scsi.c

   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 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 }