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 "s390-ccw.h"
  13 #include "virtio.h"
  14 #include "scsi.h"
  15 #include "virtio-scsi.h"
  16
  17 static ScsiDevice default_scsi_device;
  18 static VirtioScsiCmdReq req;
  19 static VirtioScsiCmdResp resp;
  20
  21 static uint8_t scsi_inquiry_std_response[256];
  22
  23 static inline void vs_assert(bool term, const char **msgs)
  24 {
  25     if (!term) {
  26         int i = 0;
  27
  28         sclp_print("\n! ");
  29         while (msgs[i]) {
  30             sclp_print(msgs[i++]);
  31         }
  32         panic(" !\n");
  33     }
  34 }
  35
  36 static void virtio_scsi_verify_response(VirtioScsiCmdResp *resp,
  37                                         const char *title)
  38 {
  39     const char *mr[] = {
  40         title, ": response ", virtio_scsi_response_msg(resp), 0
  41     };
  42     const char *ms[] = {
  43         title,
  44         CDB_STATUS_VALID(resp->status) ? ": " : ": invalid ",
  45         scsi_cdb_status_msg(resp->status),
  46         resp->status == CDB_STATUS_CHECK_CONDITION ? " " : 0,
  47         resp->sense_len ? scsi_cdb_asc_msg(resp->sense)
  48                         : "no sense data",
  49         scsi_sense_response(resp->sense)  == 0x70 ? ", sure" : "?",
  50         0
  51     };
  52
  53     vs_assert(resp->response == VIRTIO_SCSI_S_OK, mr);
  54     vs_assert(resp->status == CDB_STATUS_GOOD, ms);
  55 }
  56
  57 static void prepare_request(VDev *vdev, const void *cdb, int cdb_size,
  58                             void *data, uint32_t data_size)
  59 {
  60     const ScsiDevice *sdev = vdev->scsi_device;
  61
  62     memset(&req, 0, sizeof(req));
  63     req.lun = make_lun(sdev->channel, sdev->target, sdev->lun);
  64     memcpy(&req.cdb, cdb, cdb_size);
  65
  66     memset(&resp, 0, sizeof(resp));
  67     resp.status = 0xff;     /* set invalid  */
  68     resp.response = 0xff;   /*              */
  69
  70     if (data && data_size) {
  71         memset(data, 0, data_size);
  72     }
  73 }
  74
  75 static inline void vs_io_assert(bool term, const char *msg)
  76 {
  77     if (!term) {
  78         virtio_scsi_verify_response(&resp, msg);
  79     }
  80 }
  81
  82 static void vs_run(const char *title, VirtioCmd *cmd, VDev *vdev,
  83                    const void *cdb, int cdb_size,
  84                    void *data, uint32_t data_size)
  85 {
  86     prepare_request(vdev, cdb, cdb_size, data, data_size);
  87     vs_io_assert(virtio_run(vdev, VR_REQUEST, cmd) == 0, title);
  88 }
  89
  90 /* SCSI protocol implementation routines */
  91
  92 static bool scsi_inquiry(VDev *vdev, void *data, uint32_t data_size)
  93 {
  94     ScsiCdbInquiry cdb = {
  95         .command = 0x12,
  96         .alloc_len = data_size < 65535 ? data_size : 65535,
  97     };
  98     VirtioCmd inquiry[] = {
  99         { &req, sizeof(req), VRING_DESC_F_NEXT },
 100         { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
 101         { data, data_size, VRING_DESC_F_WRITE },
 102     };
 103
 104     vs_run("inquiry", inquiry, vdev, &cdb, sizeof(cdb), data, data_size);
 105
 106     return virtio_scsi_response_ok(&resp);
 107 }
 108
 109 static bool scsi_test_unit_ready(VDev *vdev)
 110 {
 111     ScsiCdbTestUnitReady cdb = {
 112         .command = 0x00,
 113     };
 114     VirtioCmd test_unit_ready[] = {
 115         { &req, sizeof(req), VRING_DESC_F_NEXT },
 116         { &resp, sizeof(resp), VRING_DESC_F_WRITE },
 117     };
 118
 119     prepare_request(vdev, &cdb, sizeof(cdb), 0, 0);
 120     virtio_run(vdev, VR_REQUEST, test_unit_ready); /* ignore errors here */
 121
 122     return virtio_scsi_response_ok(&resp);
 123 }
 124
 125 static bool scsi_report_luns(VDev *vdev, void *data, uint32_t data_size)
 126 {
 127     ScsiCdbReportLuns cdb = {
 128         .command = 0xa0,
 129         .select_report = 0x02, /* REPORT ALL */
 130         .alloc_len = data_size,
 131     };
 132     VirtioCmd report_luns[] = {
 133         { &req, sizeof(req), VRING_DESC_F_NEXT },
 134         { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
 135         { data, data_size, VRING_DESC_F_WRITE },
 136     };
 137
 138     vs_run("report luns", report_luns,
 139            vdev, &cdb, sizeof(cdb), data, data_size);
 140
 141     return virtio_scsi_response_ok(&resp);
 142 }
 143
 144 static bool scsi_read_10(VDev *vdev,
 145                          ulong sector, int sectors, void *data)
 146 {
 147     int f = vdev->blk_factor;
 148     unsigned int data_size = sectors * virtio_get_block_size() * f;
 149     ScsiCdbRead10 cdb = {
 150         .command = 0x28,
 151         .lba = sector * f,
 152         .xfer_length = sectors * f,
 153     };
 154     VirtioCmd read_10[] = {
 155         { &req, sizeof(req), VRING_DESC_F_NEXT },
 156         { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
 157         { data, data_size * f, VRING_DESC_F_WRITE },
 158     };
 159
 160     debug_print_int("read_10  sector", sector);
 161     debug_print_int("read_10 sectors", sectors);
 162
 163     vs_run("read(10)", read_10, vdev, &cdb, sizeof(cdb), data, data_size);
 164
 165     return virtio_scsi_response_ok(&resp);
 166 }
 167
 168 static bool scsi_read_capacity(VDev *vdev,
 169                                void *data, uint32_t data_size)
 170 {
 171     ScsiCdbReadCapacity16 cdb = {
 172         .command = 0x9e, /* SERVICE_ACTION_IN_16 */
 173         .service_action = 0x10, /* SA_READ_CAPACITY */
 174         .alloc_len = data_size,
 175     };
 176     VirtioCmd read_capacity_16[] = {
 177         { &req, sizeof(req), VRING_DESC_F_NEXT },
 178         { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
 179         { data, data_size, VRING_DESC_F_WRITE },
 180     };
 181
 182     vs_run("read capacity", read_capacity_16,
 183            vdev, &cdb, sizeof(cdb), data, data_size);
 184
 185     return virtio_scsi_response_ok(&resp);
 186 }
 187
 188 /* virtio-scsi routines */
 189
 190 static void virtio_scsi_locate_device(VDev *vdev)
 191 {
 192     const uint16_t channel = 0; /* again, it's what QEMU does */
 193     uint16_t target;
 194     static uint8_t data[16 + 8 * 63];
 195     ScsiLunReport *r = (void *) data;
 196     ScsiDevice *sdev = vdev->scsi_device;
 197     int i, luns;
 198
 199     /* QEMU has hardcoded channel #0 in many places.
 200      * If this hardcoded value is ever changed, we'll need to add code for
 201      * vdev->config.scsi.max_channel != 0 here.
 202      */
 203     debug_print_int("config.scsi.max_channel", vdev->config.scsi.max_channel);
 204     debug_print_int("config.scsi.max_target ", vdev->config.scsi.max_target);
 205     debug_print_int("config.scsi.max_lun    ", vdev->config.scsi.max_lun);
 206
 207     if (vdev->scsi_device_selected) {
 208         sdev->channel = vdev->selected_scsi_device.channel;
 209         sdev->target = vdev->selected_scsi_device.target;
 210         sdev->lun = vdev->selected_scsi_device.lun;
 211
 212         IPL_check(sdev->channel == 0, "non-zero channel requested");
 213         IPL_check(sdev->target <= vdev->config.scsi.max_target, "target# high");
 214         IPL_check(sdev->lun <= vdev->config.scsi.max_lun, "LUN# high");
 215         return;
 216     }
 217
 218     for (target = 0; target <= vdev->config.scsi.max_target; target++) {
 219         sdev->channel = channel;
 220         sdev->target = target; /* sdev->lun will be 0 here */
 221         if (!scsi_report_luns(vdev, data, sizeof(data))) {
 222             if (resp.response == VIRTIO_SCSI_S_BAD_TARGET) {
 223                 continue;
 224             }
 225             print_int("target", target);
 226             virtio_scsi_verify_response(&resp, "SCSI cannot report LUNs");
 227         }
 228         if (r->lun_list_len == 0) {
 229             print_int("no LUNs for target", target);
 230             continue;
 231         }
 232         luns = r->lun_list_len / 8;
 233         debug_print_int("LUNs reported", luns);
 234         if (luns == 1) {
 235             /* There is no ",lun=#" arg for -device or ",lun=0" given.
 236              * Hence, the only LUN reported.
 237              * Usually, it's 0.
 238              */
 239             sdev->lun = r->lun[0].v16[0]; /* it's returned this way */
 240             debug_print_int("Have to use LUN", sdev->lun);
 241             return; /* we have to use this device */
 242         }
 243         for (i = 0; i < luns; i++) {
 244             if (r->lun[i].v64) {
 245                 /* Look for non-zero LUN - we have where to choose from */
 246                 sdev->lun = r->lun[i].v16[0];
 247                 debug_print_int("Will use LUN", sdev->lun);
 248                 return; /* we have found a device */
 249             }
 250         }
 251     }
 252     panic("\n! Cannot locate virtio-scsi device !\n");
 253 }
 254
 255 int virtio_scsi_read_many(VDev *vdev,
 256                           ulong sector, void *load_addr, int sec_num)
 257 {
 258     if (!scsi_read_10(vdev, sector, sec_num, load_addr)) {
 259         virtio_scsi_verify_response(&resp, "virtio-scsi:read_many");
 260     }
 261
 262     return 0;
 263 }
 264
 265 static bool virtio_scsi_inquiry_response_is_cdrom(void *data)
 266 {
 267     const ScsiInquiryStd *response = data;
 268     const int resp_data_fmt = response->b3 & 0x0f;
 269     int i;
 270
 271     IPL_check(resp_data_fmt == 2, "Wrong INQUIRY response format");
 272     if (resp_data_fmt != 2) {
 273         return false; /* cannot decode */
 274     }
 275
 276     if ((response->peripheral_qdt & 0x1f) == SCSI_INQ_RDT_CDROM) {
 277         return true;
 278     }
 279
 280     for (i = 0; i < sizeof(response->prod_id); i++) {
 281         if (response->prod_id[i] != QEMU_CDROM_SIGNATURE[i]) {
 282             return false;
 283         }
 284     }
 285     return true;
 286 }
 287
 288 static void scsi_parse_capacity_report(void *data,
 289                                        uint64_t *last_lba, uint32_t *lb_len)
 290 {
 291     ScsiReadCapacity16Data *p = data;
 292
 293     if (last_lba) {
 294         *last_lba = p->ret_lba;
 295     }
 296
 297     if (lb_len) {
 298         *lb_len = p->lb_len;
 299     }
 300 }
 301
 302 void virtio_scsi_setup(VDev *vdev)
 303 {
 304     int retry_test_unit_ready = 3;
 305     uint8_t data[256];
 306     uint32_t data_size = sizeof(data);
 307
 308     vdev->scsi_device = &default_scsi_device;
 309     virtio_scsi_locate_device(vdev);
 310
 311     /* We have to "ping" the device before it becomes readable */
 312     while (!scsi_test_unit_ready(vdev)) {
 313
 314         if (!virtio_scsi_response_ok(&resp)) {
 315             uint8_t code = resp.sense[0] & SCSI_SENSE_CODE_MASK;
 316             uint8_t sense_key = resp.sense[2] & SCSI_SENSE_KEY_MASK;
 317
 318             IPL_assert(resp.sense_len != 0, "virtio-scsi:setup: no SENSE data");
 319
 320             IPL_assert(retry_test_unit_ready && code == 0x70 &&
 321                        sense_key == SCSI_SENSE_KEY_UNIT_ATTENTION,
 322                        "virtio-scsi:setup: cannot retry");
 323
 324             /* retry on CHECK_CONDITION/UNIT_ATTENTION as it
 325              * may not designate a real error, but it may be
 326              * a result of device reset, etc.
 327              */
 328             retry_test_unit_ready--;
 329             sleep(1);
 330             continue;
 331         }
 332
 333         virtio_scsi_verify_response(&resp, "virtio-scsi:setup");
 334     }
 335
 336     /* read and cache SCSI INQUIRY response */
 337     if (!scsi_inquiry(vdev, scsi_inquiry_std_response,
 338                       sizeof(scsi_inquiry_std_response))) {
 339         virtio_scsi_verify_response(&resp, "virtio-scsi:setup:inquiry");
 340     }
 341
 342     if (virtio_scsi_inquiry_response_is_cdrom(scsi_inquiry_std_response)) {
 343         sclp_print("SCSI CD-ROM detected.\n");
 344         vdev->is_cdrom = true;
 345         vdev->scsi_block_size = VIRTIO_ISO_BLOCK_SIZE;
 346     }
 347
 348     if (!scsi_read_capacity(vdev, data, data_size)) {
 349         virtio_scsi_verify_response(&resp, "virtio-scsi:setup:read_capacity");
 350     }
 351     scsi_parse_capacity_report(data, &vdev->scsi_last_block,
 352                                (uint32_t *) &vdev->scsi_block_size);
 353 }