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+/*
+ * Virtio-SCSI implementation for s390 machine loader for qemu
+ *
+ * Copyright 2015 IBM Corp.
+ * Author: Eugene "jno" Dvurechenski <jno@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "s390-ccw.h"
+#include "virtio.h"
+#include "scsi.h"
+#include "virtio-scsi.h"
+
+static ScsiDevice default_scsi_device;
+static VirtioScsiCmdReq req;
+static VirtioScsiCmdResp resp;
+
+static uint8_t scsi_inquiry_std_response[256];
+
+static inline void vs_assert(bool term, const char **msgs)
+{
+ if (!term) {
+ int i = 0;
+
+ sclp_print("\n! ");
+ while (msgs[i]) {
+ sclp_print(msgs[i++]);
+ }
+ panic(" !\n");
+ }
+}
+
+static void virtio_scsi_verify_response(VirtioScsiCmdResp *resp,
+ const char *title)
+{
+ const char *mr[] = {
+ title, ": response ", virtio_scsi_response_msg(resp), 0
+ };
+ const char *ms[] = {
+ title,
+ CDB_STATUS_VALID(resp->status) ? ": " : ": invalid ",
+ scsi_cdb_status_msg(resp->status),
+ resp->status == CDB_STATUS_CHECK_CONDITION ? " " : 0,
+ resp->sense_len ? scsi_cdb_asc_msg(resp->sense)
+ : "no sense data",
+ scsi_sense_response(resp->sense) == 0x70 ? ", sure" : "?",
+ 0
+ };
+
+ vs_assert(resp->response == VIRTIO_SCSI_S_OK, mr);
+ vs_assert(resp->status == CDB_STATUS_GOOD, ms);
+}
+
+static void prepare_request(VDev *vdev, const void *cdb, int cdb_size,
+ void *data, uint32_t data_size)
+{
+ const ScsiDevice *sdev = vdev->scsi_device;
+
+ memset(&req, 0, sizeof(req));
+ req.lun = make_lun(sdev->channel, sdev->target, sdev->lun);
+ memcpy(&req.cdb, cdb, cdb_size);
+
+ memset(&resp, 0, sizeof(resp));
+ resp.status = 0xff; /* set invalid */
+ resp.response = 0xff; /* */
+
+ if (data && data_size) {
+ memset(data, 0, data_size);
+ }
+}
+
+static inline void vs_io_assert(bool term, const char *msg)
+{
+ if (!term) {
+ virtio_scsi_verify_response(&resp, msg);
+ }
+}
+
+static void vs_run(const char *title, VirtioCmd *cmd, VDev *vdev,
+ const void *cdb, int cdb_size,
+ void *data, uint32_t data_size)
+{
+ prepare_request(vdev, cdb, cdb_size, data, data_size);
+ vs_io_assert(virtio_run(vdev, VR_REQUEST, cmd) == 0, title);
+}
+
+/* SCSI protocol implementation routines */
+
+static bool scsi_inquiry(VDev *vdev, void *data, uint32_t data_size)
+{
+ ScsiCdbInquiry cdb = {
+ .command = 0x12,
+ .alloc_len = data_size < 65535 ? data_size : 65535,
+ };
+ VirtioCmd inquiry[] = {
+ { &req, sizeof(req), VRING_DESC_F_NEXT },
+ { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
+ { data, data_size, VRING_DESC_F_WRITE },
+ };
+
+ vs_run("inquiry", inquiry, vdev, &cdb, sizeof(cdb), data, data_size);
+
+ return virtio_scsi_response_ok(&resp);
+}
+
+static bool scsi_test_unit_ready(VDev *vdev)
+{
+ ScsiCdbTestUnitReady cdb = {
+ .command = 0x00,
+ };
+ VirtioCmd test_unit_ready[] = {
+ { &req, sizeof(req), VRING_DESC_F_NEXT },
+ { &resp, sizeof(resp), VRING_DESC_F_WRITE },
+ };
+
+ prepare_request(vdev, &cdb, sizeof(cdb), 0, 0);
+ virtio_run(vdev, VR_REQUEST, test_unit_ready); /* ignore errors here */
+
+ return virtio_scsi_response_ok(&resp);
+}
+
+static bool scsi_report_luns(VDev *vdev, void *data, uint32_t data_size)
+{
+ ScsiCdbReportLuns cdb = {
+ .command = 0xa0,
+ .select_report = 0x02, /* REPORT ALL */
+ .alloc_len = data_size,
+ };
+ VirtioCmd report_luns[] = {
+ { &req, sizeof(req), VRING_DESC_F_NEXT },
+ { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
+ { data, data_size, VRING_DESC_F_WRITE },
+ };
+
+ vs_run("report luns", report_luns,
+ vdev, &cdb, sizeof(cdb), data, data_size);
+
+ return virtio_scsi_response_ok(&resp);
+}
+
+static bool scsi_read_10(VDev *vdev,
+ ulong sector, int sectors, void *data)
+{
+ int f = vdev->blk_factor;
+ unsigned int data_size = sectors * virtio_get_block_size() * f;
+ ScsiCdbRead10 cdb = {
+ .command = 0x28,
+ .lba = sector * f,
+ .xfer_length = sectors * f,
+ };
+ VirtioCmd read_10[] = {
+ { &req, sizeof(req), VRING_DESC_F_NEXT },
+ { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
+ { data, data_size * f, VRING_DESC_F_WRITE },
+ };
+
+ debug_print_int("read_10 sector", sector);
+ debug_print_int("read_10 sectors", sectors);
+
+ vs_run("read(10)", read_10, vdev, &cdb, sizeof(cdb), data, data_size);
+
+ return virtio_scsi_response_ok(&resp);
+}
+
+static bool scsi_read_capacity(VDev *vdev,
+ void *data, uint32_t data_size)
+{
+ ScsiCdbReadCapacity16 cdb = {
+ .command = 0x9e, /* SERVICE_ACTION_IN_16 */
+ .service_action = 0x10, /* SA_READ_CAPACITY */
+ .alloc_len = data_size,
+ };
+ VirtioCmd read_capacity_16[] = {
+ { &req, sizeof(req), VRING_DESC_F_NEXT },
+ { &resp, sizeof(resp), VRING_DESC_F_WRITE | VRING_DESC_F_NEXT },
+ { data, data_size, VRING_DESC_F_WRITE },
+ };
+
+ vs_run("read capacity", read_capacity_16,
+ vdev, &cdb, sizeof(cdb), data, data_size);
+
+ return virtio_scsi_response_ok(&resp);
+}
+
+/* virtio-scsi routines */
+
+static void virtio_scsi_locate_device(VDev *vdev)
+{
+ const uint16_t channel = 0; /* again, it's what QEMU does */
+ uint16_t target;
+ static uint8_t data[16 + 8 * 63];
+ ScsiLunReport *r = (void *) data;
+ ScsiDevice *sdev = vdev->scsi_device;
+ int i, luns;
+
+ /* QEMU has hardcoded channel #0 in many places.
+ * If this hardcoded value is ever changed, we'll need to add code for
+ * vdev->config.scsi.max_channel != 0 here.
+ */
+ debug_print_int("config.scsi.max_channel", vdev->config.scsi.max_channel);
+ debug_print_int("config.scsi.max_target ", vdev->config.scsi.max_target);
+ debug_print_int("config.scsi.max_lun ", vdev->config.scsi.max_lun);
+
+ for (target = 0; target <= vdev->config.scsi.max_target; target++) {
+ sdev->channel = channel;
+ sdev->target = target; /* sdev->lun will be 0 here */
+ if (!scsi_report_luns(vdev, data, sizeof(data))) {
+ if (resp.response == VIRTIO_SCSI_S_BAD_TARGET) {
+ continue;
+ }
+ print_int("target", target);
+ virtio_scsi_verify_response(&resp, "SCSI cannot report LUNs");
+ }
+ if (r->lun_list_len == 0) {
+ print_int("no LUNs for target", target);
+ continue;
+ }
+ luns = r->lun_list_len / 8;
+ debug_print_int("LUNs reported", luns);
+ if (luns == 1) {
+ /* There is no ",lun=#" arg for -device or ",lun=0" given.
+ * Hence, the only LUN reported.
+ * Usually, it's 0.
+ */
+ sdev->lun = r->lun[0].v16[0]; /* it's returned this way */
+ debug_print_int("Have to use LUN", sdev->lun);
+ return; /* we have to use this device */
+ }
+ for (i = 0; i < luns; i++) {
+ if (r->lun[i].v64) {
+ /* Look for non-zero LUN - we have where to choose from */
+ sdev->lun = r->lun[i].v16[0];
+ debug_print_int("Will use LUN", sdev->lun);
+ return; /* we have found a device */
+ }
+ }
+ }
+ panic("\n! Cannot locate virtio-scsi device !\n");
+}
+
+int virtio_scsi_read_many(VDev *vdev,
+ ulong sector, void *load_addr, int sec_num)
+{
+ if (!scsi_read_10(vdev, sector, sec_num, load_addr)) {
+ virtio_scsi_verify_response(&resp, "virtio-scsi:read_many");
+ }
+
+ return 0;
+}
+
+static bool virtio_scsi_inquiry_response_is_cdrom(void *data)
+{
+ const ScsiInquiryStd *response = data;
+ const int resp_data_fmt = response->b3 & 0x0f;
+ int i;
+
+ IPL_check(resp_data_fmt == 2, "Wrong INQUIRY response format");
+ if (resp_data_fmt != 2) {
+ return false; /* cannot decode */
+ }
+
+ if ((response->peripheral_qdt & 0x1f) == SCSI_INQ_RDT_CDROM) {
+ return true;
+ }
+
+ for (i = 0; i < sizeof(response->prod_id); i++) {
+ if (response->prod_id[i] != QEMU_CDROM_SIGNATURE[i]) {
+ return false;
+ }
+ }
+ return true;
+}
+
+static void scsi_parse_capacity_report(void *data,
+ uint64_t *last_lba, uint32_t *lb_len)
+{
+ ScsiReadCapacity16Data *p = data;
+
+ if (last_lba) {
+ *last_lba = p->ret_lba;
+ }
+
+ if (lb_len) {
+ *lb_len = p->lb_len;
+ }
+}
+
+void virtio_scsi_setup(VDev *vdev)
+{
+ int retry_test_unit_ready = 3;
+ uint8_t data[256];
+ uint32_t data_size = sizeof(data);
+
+ vdev->scsi_device = &default_scsi_device;
+ virtio_scsi_locate_device(vdev);
+
+ /* We have to "ping" the device before it becomes readable */
+ while (!scsi_test_unit_ready(vdev)) {
+
+ if (!virtio_scsi_response_ok(&resp)) {
+ uint8_t code = resp.sense[0] & SCSI_SENSE_CODE_MASK;
+ uint8_t sense_key = resp.sense[2] & SCSI_SENSE_KEY_MASK;
+
+ IPL_assert(resp.sense_len != 0, "virtio-scsi:setup: no SENSE data");
+
+ IPL_assert(retry_test_unit_ready && code == 0x70 &&
+ sense_key == SCSI_SENSE_KEY_UNIT_ATTENTION,
+ "virtio-scsi:setup: cannot retry");
+
+ /* retry on CHECK_CONDITION/UNIT_ATTENTION as it
+ * may not designate a real error, but it may be
+ * a result of device reset, etc.
+ */
+ retry_test_unit_ready--;
+ sleep(1);
+ continue;
+ }
+
+ virtio_scsi_verify_response(&resp, "virtio-scsi:setup");
+ }
+
+ /* read and cache SCSI INQUIRY response */
+ if (!scsi_inquiry(vdev, scsi_inquiry_std_response,
+ sizeof(scsi_inquiry_std_response))) {
+ virtio_scsi_verify_response(&resp, "virtio-scsi:setup:inquiry");
+ }
+
+ if (virtio_scsi_inquiry_response_is_cdrom(scsi_inquiry_std_response)) {
+ sclp_print("SCSI CD-ROM detected.\n");
+ vdev->is_cdrom = true;
+ vdev->scsi_block_size = VIRTIO_ISO_BLOCK_SIZE;
+ }
+
+ if (!scsi_read_capacity(vdev, data, data_size)) {
+ virtio_scsi_verify_response(&resp, "virtio-scsi:setup:read_capacity");
+ }
+ scsi_parse_capacity_report(data, &vdev->scsi_last_block,
+ (uint32_t *) &vdev->scsi_block_size);
+}
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+/*
+ * Virtio-SCSI definitions for s390 machine loader for qemu
+ *
+ * Copyright 2015 IBM Corp.
+ * Author: Eugene "jno" Dvurechenski <jno@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef VIRTIO_SCSI_H
+#define VIRTIO_SCSI_H
+
+#include "s390-ccw.h"
+#include "virtio.h"
+#include "scsi.h"
+
+#define VIRTIO_SCSI_CDB_SIZE SCSI_DEFAULT_CDB_SIZE
+#define VIRTIO_SCSI_SENSE_SIZE SCSI_DEFAULT_SENSE_SIZE
+
+/* command-specific response values */
+#define VIRTIO_SCSI_S_OK 0x00
+#define VIRTIO_SCSI_S_BAD_TARGET 0x03
+
+#define QEMU_CDROM_SIGNATURE "QEMU CD-ROM "
+
+enum virtio_scsi_vq_id {
+ VR_CONTROL = 0,
+ VR_EVENT = 1,
+ VR_REQUEST = 2,
+};
+
+struct VirtioScsiCmdReq {
+ ScsiLun lun;
+ uint64_t id;
+ uint8_t task_attr; /* = 0 = VIRTIO_SCSI_S_SIMPLE */
+ uint8_t prio;
+ uint8_t crn; /* = 0 */
+ uint8_t cdb[VIRTIO_SCSI_CDB_SIZE];
+} __attribute__((packed));
+typedef struct VirtioScsiCmdReq VirtioScsiCmdReq;
+
+struct VirtioScsiCmdResp {
+ uint32_t sense_len;
+ uint32_t residual;
+ uint16_t status_qualifier;
+ uint8_t status; /* first check for .response */
+ uint8_t response; /* then for .status */
+ uint8_t sense[VIRTIO_SCSI_SENSE_SIZE];
+} __attribute__((packed));
+typedef struct VirtioScsiCmdResp VirtioScsiCmdResp;
+
+static inline const char *virtio_scsi_response_msg(const VirtioScsiCmdResp *r)
+{
+ static char err_msg[] = "VS RESP=XX";
+ uint8_t v = r->response;
+
+ fill_hex_val(err_msg + 8, &v, 1);
+ return err_msg;
+}
+
+static inline bool virtio_scsi_response_ok(const VirtioScsiCmdResp *r)
+{
+ return r->response == VIRTIO_SCSI_S_OK && r->status == CDB_STATUS_GOOD;
+}
+
+void virtio_scsi_setup(VDev *vdev);
+int virtio_scsi_read_many(VDev *vdev,
+ ulong sector, void *load_addr, int sec_num);
+
+#endif /* VIRTIO_SCSI_H */