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
  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;
 227         sdev->lun = 0;          /* LUN has to be 0 for REPORT LUNS */
 228         if (!scsi_report_luns(vdev, data, sizeof(data))) {
 229             if (resp.response == VIRTIO_SCSI_S_BAD_TARGET) {
 230                 continue;
 231             }
 232             print_int("target", target);
 233             virtio_scsi_verify_response(&resp, "SCSI cannot report LUNs");
 234         }
 235         if (r->lun_list_len == 0) {
 236             print_int("no LUNs for target", target);
 237             continue;
 238         }
 239         luns = r->lun_list_len / 8;
 240         debug_print_int("LUNs reported", luns);
 241         if (luns == 1) {
 242             /* There is no ",lun=#" arg for -device or ",lun=0" given.
 243              * Hence, the only LUN reported.
 244              * Usually, it's 0.
 245              */
 246             sdev->lun = r->lun[0].v16[0]; /* it's returned this way */
 247             debug_print_int("Have to use LUN", sdev->lun);
 248             return; /* we have to use this device */
 249         }
 250         for (i = 0; i < luns; i++) {
 251             if (r->lun[i].v64) {
 252                 /* Look for non-zero LUN - we have where to choose from */
 253                 sdev->lun = r->lun[i].v16[0];
 254                 debug_print_int("Will use LUN", sdev->lun);
 255                 return; /* we have found a device */
 256             }
 257         }
 258     }
 259     panic("\n! Cannot locate virtio-scsi device !\n");
 260 }
 261
 262 int virtio_scsi_read_many(VDev *vdev,
 263                           ulong sector, void *load_addr, int sec_num)
 264 {
 265     int sector_count;
 266     int f = vdev->blk_factor;
 267     unsigned int data_size;
 268     unsigned int max_transfer = MIN_NON_ZERO(vdev->config.scsi.max_sectors,
 269                                              vdev->max_transfer);
 270
 271     do {
 272         sector_count = MIN_NON_ZERO(sec_num, max_transfer);
 273         data_size = sector_count * virtio_get_block_size() * f;
 274         if (!scsi_read_10(vdev, sector * f, sector_count * f, load_addr,
 275                           data_size)) {
 276             virtio_scsi_verify_response(&resp, "virtio-scsi:read_many");
 277         }
 278         load_addr += data_size;
 279         sector += sector_count;
 280         sec_num -= sector_count;
 281     } while (sec_num > 0);
 282
 283     return 0;
 284 }
 285
 286 static bool virtio_scsi_inquiry_response_is_cdrom(void *data)
 287 {
 288     const ScsiInquiryStd *response = data;
 289     const int resp_data_fmt = response->b3 & 0x0f;
 290     int i;
 291
 292     IPL_check(resp_data_fmt == 2, "Wrong INQUIRY response format");
 293     if (resp_data_fmt != 2) {
 294         return false; /* cannot decode */
 295     }
 296
 297     if ((response->peripheral_qdt & 0x1f) == SCSI_INQ_RDT_CDROM) {
 298         return true;
 299     }
 300
 301     for (i = 0; i < sizeof(response->prod_id); i++) {
 302         if (response->prod_id[i] != QEMU_CDROM_SIGNATURE[i]) {
 303             return false;
 304         }
 305     }
 306     return true;
 307 }
 308
 309 static void scsi_parse_capacity_report(void *data,
 310                                        uint64_t *last_lba, uint32_t *lb_len)
 311 {
 312     ScsiReadCapacity16Data *p = data;
 313
 314     if (last_lba) {
 315         *last_lba = p->ret_lba;
 316     }
 317
 318     if (lb_len) {
 319         *lb_len = p->lb_len;
 320     }
 321 }
 322
 323 void virtio_scsi_setup(VDev *vdev)
 324 {
 325     int retry_test_unit_ready = 3;
 326     uint8_t data[256];
 327     uint32_t data_size = sizeof(data);
 328     ScsiInquiryEvpdPages *evpd = &scsi_inquiry_evpd_pages_response;
 329     ScsiInquiryEvpdBl *evpd_bl = &scsi_inquiry_evpd_bl_response;
 330     int i;
 331
 332     vdev->scsi_device = &default_scsi_device;
 333     virtio_scsi_locate_device(vdev);
 334
 335     /* We have to "ping" the device before it becomes readable */
 336     while (!scsi_test_unit_ready(vdev)) {
 337
 338         if (!virtio_scsi_response_ok(&resp)) {
 339             uint8_t code = resp.sense[0] & SCSI_SENSE_CODE_MASK;
 340             uint8_t sense_key = resp.sense[2] & SCSI_SENSE_KEY_MASK;
 341
 342             IPL_assert(resp.sense_len != 0, "virtio-scsi:setup: no SENSE data");
 343
 344             IPL_assert(retry_test_unit_ready && code == 0x70 &&
 345                        sense_key == SCSI_SENSE_KEY_UNIT_ATTENTION,
 346                        "virtio-scsi:setup: cannot retry");
 347
 348             /* retry on CHECK_CONDITION/UNIT_ATTENTION as it
 349              * may not designate a real error, but it may be
 350              * a result of device reset, etc.
 351              */
 352             retry_test_unit_ready--;
 353             sleep(1);
 354             continue;
 355         }
 356
 357         virtio_scsi_verify_response(&resp, "virtio-scsi:setup");
 358     }
 359
 360     /* read and cache SCSI INQUIRY response */
 361     if (!scsi_inquiry(vdev,
 362                       SCSI_INQUIRY_STANDARD,
 363                       SCSI_INQUIRY_STANDARD_NONE,
 364                       scsi_inquiry_std_response,
 365                       sizeof(scsi_inquiry_std_response))) {
 366         virtio_scsi_verify_response(&resp, "virtio-scsi:setup:inquiry");
 367     }
 368
 369     if (virtio_scsi_inquiry_response_is_cdrom(scsi_inquiry_std_response)) {
 370         sclp_print("SCSI CD-ROM detected.\n");
 371         vdev->is_cdrom = true;
 372         vdev->scsi_block_size = VIRTIO_ISO_BLOCK_SIZE;
 373     }
 374
 375     if (!scsi_inquiry(vdev,
 376                       SCSI_INQUIRY_EVPD,
 377                       SCSI_INQUIRY_EVPD_SUPPORTED_PAGES,
 378                       evpd,
 379                       sizeof(*evpd))) {
 380         virtio_scsi_verify_response(&resp, "virtio-scsi:setup:supported_pages");
 381     }
 382
 383     debug_print_int("EVPD length", evpd->page_length);
 384
 385     for (i = 0; i <= evpd->page_length; i++) {
 386         debug_print_int("supported EVPD page", evpd->byte[i]);
 387
 388         if (evpd->byte[i] != SCSI_INQUIRY_EVPD_BLOCK_LIMITS) {
 389             continue;
 390         }
 391
 392         if (!scsi_inquiry(vdev,
 393                           SCSI_INQUIRY_EVPD,
 394                           SCSI_INQUIRY_EVPD_BLOCK_LIMITS,
 395                           evpd_bl,
 396                           sizeof(*evpd_bl))) {
 397             virtio_scsi_verify_response(&resp, "virtio-scsi:setup:blocklimits");
 398         }
 399
 400         debug_print_int("max transfer", evpd_bl->max_transfer);
 401         vdev->max_transfer = evpd_bl->max_transfer;
 402     }
 403
 404     /*
 405      * The host sg driver will often be unhappy with particularly large
 406      * I/Os that exceed the block iovec limits.  Let's enforce something
 407      * reasonable, despite what the device configuration tells us.
 408      */
 409
 410     vdev->max_transfer = MIN_NON_ZERO(VIRTIO_SCSI_MAX_SECTORS,
 411                                       vdev->max_transfer);
 412
 413     if (!scsi_read_capacity(vdev, data, data_size)) {
 414         virtio_scsi_verify_response(&resp, "virtio-scsi:setup:read_capacity");
 415     }
 416     scsi_parse_capacity_report(data, &vdev->scsi_last_block,
 417                                (uint32_t *) &vdev->scsi_block_size);
 418 }