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-rw-r--r--hw/ufs/lu.c1445
1 files changed, 1445 insertions, 0 deletions
diff --git a/hw/ufs/lu.c b/hw/ufs/lu.c
new file mode 100644
index 0000000000..e1c46bddb1
--- /dev/null
+++ b/hw/ufs/lu.c
@@ -0,0 +1,1445 @@
+/*
+ * QEMU UFS Logical Unit
+ *
+ * Copyright (c) 2023 Samsung Electronics Co., Ltd. All rights reserved.
+ *
+ * Written by Jeuk Kim <jeuk20.kim@samsung.com>
+ *
+ * This code is licensed under the GNU GPL v2 or later.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qapi/error.h"
+#include "qemu/memalign.h"
+#include "hw/scsi/scsi.h"
+#include "scsi/constants.h"
+#include "sysemu/block-backend.h"
+#include "qemu/cutils.h"
+#include "trace.h"
+#include "ufs.h"
+
+/*
+ * The code below handling SCSI commands is copied from hw/scsi/scsi-disk.c,
+ * with minor adjustments to make it work for UFS.
+ */
+
+#define SCSI_DMA_BUF_SIZE (128 * KiB)
+#define SCSI_MAX_INQUIRY_LEN 256
+#define SCSI_INQUIRY_DATA_SIZE 36
+#define SCSI_MAX_MODE_LEN 256
+
+typedef struct UfsSCSIReq {
+    SCSIRequest req;
+    /* Both sector and sector_count are in terms of BDRV_SECTOR_SIZE bytes.  */
+    uint64_t sector;
+    uint32_t sector_count;
+    uint32_t buflen;
+    bool started;
+    bool need_fua_emulation;
+    struct iovec iov;
+    QEMUIOVector qiov;
+    BlockAcctCookie acct;
+} UfsSCSIReq;
+
+static void ufs_scsi_free_request(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+
+    qemu_vfree(r->iov.iov_base);
+}
+
+static void scsi_check_condition(UfsSCSIReq *r, SCSISense sense)
+{
+    trace_ufs_scsi_check_condition(r->req.tag, sense.key, sense.asc,
+                                   sense.ascq);
+    scsi_req_build_sense(&r->req, sense);
+    scsi_req_complete(&r->req, CHECK_CONDITION);
+}
+
+static int ufs_scsi_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf,
+                                     uint32_t outbuf_len)
+{
+    UfsHc *u = UFS(req->bus->qbus.parent);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
+    uint8_t page_code = req->cmd.buf[2];
+    int start, buflen = 0;
+
+    if (outbuf_len < SCSI_INQUIRY_DATA_SIZE) {
+        return -1;
+    }
+
+    outbuf[buflen++] = lu->qdev.type & 0x1f;
+    outbuf[buflen++] = page_code;
+    outbuf[buflen++] = 0x00;
+    outbuf[buflen++] = 0x00;
+    start = buflen;
+
+    switch (page_code) {
+    case 0x00: /* Supported page codes, mandatory */
+    {
+        trace_ufs_scsi_emulate_vpd_page_00(req->cmd.xfer);
+        outbuf[buflen++] = 0x00; /* list of supported pages (this page) */
+        if (u->params.serial) {
+            outbuf[buflen++] = 0x80; /* unit serial number */
+        }
+        outbuf[buflen++] = 0x87; /* mode page policy */
+        break;
+    }
+    case 0x80: /* Device serial number, optional */
+    {
+        int l;
+
+        if (!u->params.serial) {
+            trace_ufs_scsi_emulate_vpd_page_80_not_supported();
+            return -1;
+        }
+
+        l = strlen(u->params.serial);
+        if (l > SCSI_INQUIRY_DATA_SIZE) {
+            l = SCSI_INQUIRY_DATA_SIZE;
+        }
+
+        trace_ufs_scsi_emulate_vpd_page_80(req->cmd.xfer);
+        memcpy(outbuf + buflen, u->params.serial, l);
+        buflen += l;
+        break;
+    }
+    case 0x87: /* Mode Page Policy, mandatory */
+    {
+        trace_ufs_scsi_emulate_vpd_page_87(req->cmd.xfer);
+        outbuf[buflen++] = 0x3f; /* apply to all mode pages and subpages */
+        outbuf[buflen++] = 0xff;
+        outbuf[buflen++] = 0; /* shared */
+        outbuf[buflen++] = 0;
+        break;
+    }
+    default:
+        return -1;
+    }
+    /* done with EVPD */
+    assert(buflen - start <= 255);
+    outbuf[start - 1] = buflen - start;
+    return buflen;
+}
+
+static int ufs_scsi_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf,
+                                    uint32_t outbuf_len)
+{
+    int buflen = 0;
+
+    if (outbuf_len < SCSI_INQUIRY_DATA_SIZE) {
+        return -1;
+    }
+
+    if (req->cmd.buf[1] & 0x1) {
+        /* Vital product data */
+        return ufs_scsi_emulate_vpd_page(req, outbuf, outbuf_len);
+    }
+
+    /* Standard INQUIRY data */
+    if (req->cmd.buf[2] != 0) {
+        return -1;
+    }
+
+    /* PAGE CODE == 0 */
+    buflen = req->cmd.xfer;
+    if (buflen > SCSI_MAX_INQUIRY_LEN) {
+        buflen = SCSI_MAX_INQUIRY_LEN;
+    }
+
+    if (is_wlun(req->lun)) {
+        outbuf[0] = TYPE_WLUN;
+    } else {
+        outbuf[0] = 0;
+    }
+    outbuf[1] = 0;
+
+    strpadcpy((char *)&outbuf[16], 16, "QEMU UFS", ' ');
+    strpadcpy((char *)&outbuf[8], 8, "QEMU", ' ');
+
+    memset(&outbuf[32], 0, 4);
+
+    outbuf[2] = 0x06; /* SPC-4 */
+    outbuf[3] = 0x2;
+
+    if (buflen > SCSI_INQUIRY_DATA_SIZE) {
+        outbuf[4] = buflen - 5; /* Additional Length = (Len - 1) - 4 */
+    } else {
+        /*
+         * If the allocation length of CDB is too small, the additional
+         * length is not adjusted
+         */
+        outbuf[4] = SCSI_INQUIRY_DATA_SIZE - 5;
+    }
+
+    /* Support TCQ.  */
+    outbuf[7] = req->bus->info->tcq ? 0x02 : 0;
+    return buflen;
+}
+
+static int mode_sense_page(UfsLu *lu, int page, uint8_t **p_outbuf,
+                           int page_control)
+{
+    static const int mode_sense_valid[0x3f] = {
+        [MODE_PAGE_CACHING] = 1,
+        [MODE_PAGE_R_W_ERROR] = 1,
+        [MODE_PAGE_CONTROL] = 1,
+    };
+
+    uint8_t *p = *p_outbuf + 2;
+    int length;
+
+    assert(page < ARRAY_SIZE(mode_sense_valid));
+    if ((mode_sense_valid[page]) == 0) {
+        return -1;
+    }
+
+    /*
+     * If Changeable Values are requested, a mask denoting those mode parameters
+     * that are changeable shall be returned. As we currently don't support
+     * parameter changes via MODE_SELECT all bits are returned set to zero.
+     * The buffer was already memset to zero by the caller of this function.
+     */
+    switch (page) {
+    case MODE_PAGE_CACHING:
+        length = 0x12;
+        if (page_control == 1 || /* Changeable Values */
+            blk_enable_write_cache(lu->qdev.conf.blk)) {
+            p[0] = 4; /* WCE */
+        }
+        break;
+
+    case MODE_PAGE_R_W_ERROR:
+        length = 10;
+        if (page_control == 1) { /* Changeable Values */
+            break;
+        }
+        p[0] = 0x80; /* Automatic Write Reallocation Enabled */
+        break;
+
+    case MODE_PAGE_CONTROL:
+        length = 10;
+        if (page_control == 1) { /* Changeable Values */
+            break;
+        }
+        p[1] = 0x10; /* Queue Algorithm modifier */
+        p[8] = 0xff; /* Busy Timeout Period */
+        p[9] = 0xff;
+        break;
+
+    default:
+        return -1;
+    }
+
+    assert(length < 256);
+    (*p_outbuf)[0] = page;
+    (*p_outbuf)[1] = length;
+    *p_outbuf += length + 2;
+    return length + 2;
+}
+
+static int ufs_scsi_emulate_mode_sense(UfsSCSIReq *r, uint8_t *outbuf)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    bool dbd;
+    int page, buflen, ret, page_control;
+    uint8_t *p;
+    uint8_t dev_specific_param = 0;
+
+    dbd = (r->req.cmd.buf[1] & 0x8) != 0;
+    if (!dbd) {
+        return -1;
+    }
+
+    page = r->req.cmd.buf[2] & 0x3f;
+    page_control = (r->req.cmd.buf[2] & 0xc0) >> 6;
+
+    trace_ufs_scsi_emulate_mode_sense((r->req.cmd.buf[0] == MODE_SENSE) ? 6 :
+                                                                          10,
+                                      page, r->req.cmd.xfer, page_control);
+    memset(outbuf, 0, r->req.cmd.xfer);
+    p = outbuf;
+
+    if (!blk_is_writable(lu->qdev.conf.blk)) {
+        dev_specific_param |= 0x80; /* Readonly.  */
+    }
+
+    p[2] = 0; /* Medium type.  */
+    p[3] = dev_specific_param;
+    p[6] = p[7] = 0; /* Block descriptor length.  */
+    p += 8;
+
+    if (page_control == 3) {
+        /* Saved Values */
+        scsi_check_condition(r, SENSE_CODE(SAVING_PARAMS_NOT_SUPPORTED));
+        return -1;
+    }
+
+    if (page == 0x3f) {
+        for (page = 0; page <= 0x3e; page++) {
+            mode_sense_page(lu, page, &p, page_control);
+        }
+    } else {
+        ret = mode_sense_page(lu, page, &p, page_control);
+        if (ret == -1) {
+            return -1;
+        }
+    }
+
+    buflen = p - outbuf;
+    /*
+     * The mode data length field specifies the length in bytes of the
+     * following data that is available to be transferred. The mode data
+     * length does not include itself.
+     */
+    outbuf[0] = ((buflen - 2) >> 8) & 0xff;
+    outbuf[1] = (buflen - 2) & 0xff;
+    return buflen;
+}
+
+/*
+ * scsi_handle_rw_error has two return values.  False means that the error
+ * must be ignored, true means that the error has been processed and the
+ * caller should not do anything else for this request.  Note that
+ * scsi_handle_rw_error always manages its reference counts, independent
+ * of the return value.
+ */
+static bool scsi_handle_rw_error(UfsSCSIReq *r, int ret, bool acct_failed)
+{
+    bool is_read = (r->req.cmd.mode == SCSI_XFER_FROM_DEV);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    SCSISense sense = SENSE_CODE(NO_SENSE);
+    int error = 0;
+    bool req_has_sense = false;
+    BlockErrorAction action;
+    int status;
+
+    if (ret < 0) {
+        status = scsi_sense_from_errno(-ret, &sense);
+        error = -ret;
+    } else {
+        /* A passthrough command has completed with nonzero status.  */
+        status = ret;
+        if (status == CHECK_CONDITION) {
+            req_has_sense = true;
+            error = scsi_sense_buf_to_errno(r->req.sense, sizeof(r->req.sense));
+        } else {
+            error = EINVAL;
+        }
+    }
+
+    /*
+     * Check whether the error has to be handled by the guest or should
+     * rather follow the rerror=/werror= settings.  Guest-handled errors
+     * are usually retried immediately, so do not post them to QMP and
+     * do not account them as failed I/O.
+     */
+    if (req_has_sense && scsi_sense_buf_is_guest_recoverable(
+                             r->req.sense, sizeof(r->req.sense))) {
+        action = BLOCK_ERROR_ACTION_REPORT;
+        acct_failed = false;
+    } else {
+        action = blk_get_error_action(lu->qdev.conf.blk, is_read, error);
+        blk_error_action(lu->qdev.conf.blk, action, is_read, error);
+    }
+
+    switch (action) {
+    case BLOCK_ERROR_ACTION_REPORT:
+        if (acct_failed) {
+            block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+        }
+        if (!req_has_sense && status == CHECK_CONDITION) {
+            scsi_req_build_sense(&r->req, sense);
+        }
+        scsi_req_complete(&r->req, status);
+        return true;
+
+    case BLOCK_ERROR_ACTION_IGNORE:
+        return false;
+
+    case BLOCK_ERROR_ACTION_STOP:
+        scsi_req_retry(&r->req);
+        return true;
+
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static bool ufs_scsi_req_check_error(UfsSCSIReq *r, int ret, bool acct_failed)
+{
+    if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
+        return true;
+    }
+
+    if (ret < 0) {
+        return scsi_handle_rw_error(r, ret, acct_failed);
+    }
+
+    return false;
+}
+
+static void scsi_aio_complete(void *opaque, int ret)
+{
+    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb != NULL);
+    r->req.aiocb = NULL;
+    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
+    if (ufs_scsi_req_check_error(r, ret, true)) {
+        goto done;
+    }
+
+    block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    scsi_req_complete(&r->req, GOOD);
+
+done:
+    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
+    scsi_req_unref(&r->req);
+}
+
+static int32_t ufs_scsi_emulate_command(SCSIRequest *req, uint8_t *buf)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
+    uint32_t last_block = 0;
+    uint8_t *outbuf;
+    int buflen;
+
+    switch (req->cmd.buf[0]) {
+    case INQUIRY:
+    case MODE_SENSE_10:
+    case START_STOP:
+    case REQUEST_SENSE:
+        break;
+
+    default:
+        if (!blk_is_available(lu->qdev.conf.blk)) {
+            scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
+            return 0;
+        }
+        break;
+    }
+
+    /*
+     * FIXME: we shouldn't return anything bigger than 4k, but the code
+     * requires the buffer to be as big as req->cmd.xfer in several
+     * places.  So, do not allow CDBs with a very large ALLOCATION
+     * LENGTH.  The real fix would be to modify scsi_read_data and
+     * dma_buf_read, so that they return data beyond the buflen
+     * as all zeros.
+     */
+    if (req->cmd.xfer > 65536) {
+        goto illegal_request;
+    }
+    r->buflen = MAX(4096, req->cmd.xfer);
+
+    if (!r->iov.iov_base) {
+        r->iov.iov_base = blk_blockalign(lu->qdev.conf.blk, r->buflen);
+    }
+
+    outbuf = r->iov.iov_base;
+    memset(outbuf, 0, r->buflen);
+    switch (req->cmd.buf[0]) {
+    case TEST_UNIT_READY:
+        assert(blk_is_available(lu->qdev.conf.blk));
+        break;
+    case INQUIRY:
+        buflen = ufs_scsi_emulate_inquiry(req, outbuf, r->buflen);
+        if (buflen < 0) {
+            goto illegal_request;
+        }
+        break;
+    case MODE_SENSE_10:
+        buflen = ufs_scsi_emulate_mode_sense(r, outbuf);
+        if (buflen < 0) {
+            goto illegal_request;
+        }
+        break;
+    case READ_CAPACITY_10:
+        /* The normal LEN field for this command is zero.  */
+        memset(outbuf, 0, 8);
+        if (lu->qdev.max_lba > 0) {
+            last_block = lu->qdev.max_lba - 1;
+        };
+        outbuf[0] = (last_block >> 24) & 0xff;
+        outbuf[1] = (last_block >> 16) & 0xff;
+        outbuf[2] = (last_block >> 8) & 0xff;
+        outbuf[3] = last_block & 0xff;
+        outbuf[4] = (lu->qdev.blocksize >> 24) & 0xff;
+        outbuf[5] = (lu->qdev.blocksize >> 16) & 0xff;
+        outbuf[6] = (lu->qdev.blocksize >> 8) & 0xff;
+        outbuf[7] = lu->qdev.blocksize & 0xff;
+        break;
+    case REQUEST_SENSE:
+        /* Just return "NO SENSE".  */
+        buflen = scsi_convert_sense(NULL, 0, outbuf, r->buflen,
+                                    (req->cmd.buf[1] & 1) == 0);
+        if (buflen < 0) {
+            goto illegal_request;
+        }
+        break;
+    case SYNCHRONIZE_CACHE:
+        /* The request is used as the AIO opaque value, so add a ref.  */
+        scsi_req_ref(&r->req);
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
+                         BLOCK_ACCT_FLUSH);
+        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
+        return 0;
+    case VERIFY_10:
+        trace_ufs_scsi_emulate_command_VERIFY((req->cmd.buf[1] >> 1) & 3);
+        if (req->cmd.buf[1] & 6) {
+            goto illegal_request;
+        }
+        break;
+    case SERVICE_ACTION_IN_16:
+        /* Service Action In subcommands. */
+        if ((req->cmd.buf[1] & 31) == SAI_READ_CAPACITY_16) {
+            trace_ufs_scsi_emulate_command_SAI_16();
+            memset(outbuf, 0, req->cmd.xfer);
+
+            if (lu->qdev.max_lba > 0) {
+                last_block = lu->qdev.max_lba - 1;
+            };
+            outbuf[0] = 0;
+            outbuf[1] = 0;
+            outbuf[2] = 0;
+            outbuf[3] = 0;
+            outbuf[4] = (last_block >> 24) & 0xff;
+            outbuf[5] = (last_block >> 16) & 0xff;
+            outbuf[6] = (last_block >> 8) & 0xff;
+            outbuf[7] = last_block & 0xff;
+            outbuf[8] = (lu->qdev.blocksize >> 24) & 0xff;
+            outbuf[9] = (lu->qdev.blocksize >> 16) & 0xff;
+            outbuf[10] = (lu->qdev.blocksize >> 8) & 0xff;
+            outbuf[11] = lu->qdev.blocksize & 0xff;
+            outbuf[12] = 0;
+            outbuf[13] = get_physical_block_exp(&lu->qdev.conf);
+
+            if (lu->unit_desc.provisioning_type == 2 ||
+                lu->unit_desc.provisioning_type == 3) {
+                outbuf[14] = 0x80;
+            }
+            /* Protection, exponent and lowest lba field left blank. */
+            break;
+        }
+        trace_ufs_scsi_emulate_command_SAI_unsupported();
+        goto illegal_request;
+    case MODE_SELECT_10:
+        trace_ufs_scsi_emulate_command_MODE_SELECT_10(r->req.cmd.xfer);
+        break;
+    case START_STOP:
+        /*
+         * TODO: START_STOP is not yet implemented. It always returns success.
+         * Revisit it when ufs power management is implemented.
+         */
+        trace_ufs_scsi_emulate_command_START_STOP();
+        break;
+    case FORMAT_UNIT:
+        trace_ufs_scsi_emulate_command_FORMAT_UNIT();
+        break;
+    case SEND_DIAGNOSTIC:
+        trace_ufs_scsi_emulate_command_SEND_DIAGNOSTIC();
+        break;
+    default:
+        trace_ufs_scsi_emulate_command_UNKNOWN(buf[0],
+                                               scsi_command_name(buf[0]));
+        scsi_check_condition(r, SENSE_CODE(INVALID_OPCODE));
+        return 0;
+    }
+    assert(!r->req.aiocb);
+    r->iov.iov_len = MIN(r->buflen, req->cmd.xfer);
+    if (r->iov.iov_len == 0) {
+        scsi_req_complete(&r->req, GOOD);
+    }
+    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+        assert(r->iov.iov_len == req->cmd.xfer);
+        return -r->iov.iov_len;
+    } else {
+        return r->iov.iov_len;
+    }
+
+illegal_request:
+    if (r->req.status == -1) {
+        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
+    }
+    return 0;
+}
+
+static void ufs_scsi_emulate_read_data(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+    int buflen = r->iov.iov_len;
+
+    if (buflen) {
+        trace_ufs_scsi_emulate_read_data(buflen);
+        r->iov.iov_len = 0;
+        r->started = true;
+        scsi_req_data(&r->req, buflen);
+        return;
+    }
+
+    /* This also clears the sense buffer for REQUEST SENSE.  */
+    scsi_req_complete(&r->req, GOOD);
+}
+
+static int ufs_scsi_check_mode_select(UfsLu *lu, int page, uint8_t *inbuf,
+                                      int inlen)
+{
+    uint8_t mode_current[SCSI_MAX_MODE_LEN];
+    uint8_t mode_changeable[SCSI_MAX_MODE_LEN];
+    uint8_t *p;
+    int len, expected_len, changeable_len, i;
+
+    /*
+     * The input buffer does not include the page header, so it is
+     * off by 2 bytes.
+     */
+    expected_len = inlen + 2;
+    if (expected_len > SCSI_MAX_MODE_LEN) {
+        return -1;
+    }
+
+    /* MODE_PAGE_ALLS is only valid for MODE SENSE commands */
+    if (page == MODE_PAGE_ALLS) {
+        return -1;
+    }
+
+    p = mode_current;
+    memset(mode_current, 0, inlen + 2);
+    len = mode_sense_page(lu, page, &p, 0);
+    if (len < 0 || len != expected_len) {
+        return -1;
+    }
+
+    p = mode_changeable;
+    memset(mode_changeable, 0, inlen + 2);
+    changeable_len = mode_sense_page(lu, page, &p, 1);
+    assert(changeable_len == len);
+
+    /*
+     * Check that unchangeable bits are the same as what MODE SENSE
+     * would return.
+     */
+    for (i = 2; i < len; i++) {
+        if (((mode_current[i] ^ inbuf[i - 2]) & ~mode_changeable[i]) != 0) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
+static void ufs_scsi_apply_mode_select(UfsLu *lu, int page, uint8_t *p)
+{
+    switch (page) {
+    case MODE_PAGE_CACHING:
+        blk_set_enable_write_cache(lu->qdev.conf.blk, (p[0] & 4) != 0);
+        break;
+
+    default:
+        break;
+    }
+}
+
+static int mode_select_pages(UfsSCSIReq *r, uint8_t *p, int len, bool change)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    while (len > 0) {
+        int page, page_len;
+
+        page = p[0] & 0x3f;
+        if (p[0] & 0x40) {
+            goto invalid_param;
+        } else {
+            if (len < 2) {
+                goto invalid_param_len;
+            }
+            page_len = p[1];
+            p += 2;
+            len -= 2;
+        }
+
+        if (page_len > len) {
+            goto invalid_param_len;
+        }
+
+        if (!change) {
+            if (ufs_scsi_check_mode_select(lu, page, p, page_len) < 0) {
+                goto invalid_param;
+            }
+        } else {
+            ufs_scsi_apply_mode_select(lu, page, p);
+        }
+
+        p += page_len;
+        len -= page_len;
+    }
+    return 0;
+
+invalid_param:
+    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM));
+    return -1;
+
+invalid_param_len:
+    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
+    return -1;
+}
+
+static void ufs_scsi_emulate_mode_select(UfsSCSIReq *r, uint8_t *inbuf)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    uint8_t *p = inbuf;
+    int len = r->req.cmd.xfer;
+    int hdr_len = 8;
+    int bd_len;
+    int pass;
+
+    /* We only support PF=1, SP=0.  */
+    if ((r->req.cmd.buf[1] & 0x11) != 0x10) {
+        goto invalid_field;
+    }
+
+    if (len < hdr_len) {
+        goto invalid_param_len;
+    }
+
+    bd_len = lduw_be_p(&p[6]);
+    if (bd_len != 0) {
+        goto invalid_param;
+    }
+
+    len -= hdr_len;
+    p += hdr_len;
+
+    /* Ensure no change is made if there is an error!  */
+    for (pass = 0; pass < 2; pass++) {
+        if (mode_select_pages(r, p, len, pass == 1) < 0) {
+            assert(pass == 0);
+            return;
+        }
+    }
+
+    if (!blk_enable_write_cache(lu->qdev.conf.blk)) {
+        /* The request is used as the AIO opaque value, so add a ref.  */
+        scsi_req_ref(&r->req);
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
+                         BLOCK_ACCT_FLUSH);
+        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
+        return;
+    }
+
+    scsi_req_complete(&r->req, GOOD);
+    return;
+
+invalid_param:
+    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM));
+    return;
+
+invalid_param_len:
+    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
+    return;
+
+invalid_field:
+    scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
+}
+
+/* block_num and nb_blocks expected to be in qdev blocksize */
+static inline bool check_lba_range(UfsLu *lu, uint64_t block_num,
+                                   uint32_t nb_blocks)
+{
+    /*
+     * The first line tests that no overflow happens when computing the last
+     * block.  The second line tests that the last accessed block is in
+     * range.
+     *
+     * Careful, the computations should not underflow for nb_blocks == 0,
+     * and a 0-block read to the first LBA beyond the end of device is
+     * valid.
+     */
+    return (block_num <= block_num + nb_blocks &&
+            block_num + nb_blocks <= lu->qdev.max_lba + 1);
+}
+
+static void ufs_scsi_emulate_write_data(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+
+    if (r->iov.iov_len) {
+        int buflen = r->iov.iov_len;
+        trace_ufs_scsi_emulate_write_data(buflen);
+        r->iov.iov_len = 0;
+        scsi_req_data(&r->req, buflen);
+        return;
+    }
+
+    switch (req->cmd.buf[0]) {
+    case MODE_SELECT_10:
+        /* This also clears the sense buffer for REQUEST SENSE.  */
+        ufs_scsi_emulate_mode_select(r, r->iov.iov_base);
+        break;
+    default:
+        abort();
+    }
+}
+
+/* Return a pointer to the data buffer.  */
+static uint8_t *ufs_scsi_get_buf(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+
+    return (uint8_t *)r->iov.iov_base;
+}
+
+static int32_t ufs_scsi_dma_command(SCSIRequest *req, uint8_t *buf)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
+    uint32_t len;
+    uint8_t command;
+
+    command = buf[0];
+
+    if (!blk_is_available(lu->qdev.conf.blk)) {
+        scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
+        return 0;
+    }
+
+    len = scsi_data_cdb_xfer(r->req.cmd.buf);
+    switch (command) {
+    case READ_6:
+    case READ_10:
+        trace_ufs_scsi_dma_command_READ(r->req.cmd.lba, len);
+        if (r->req.cmd.buf[1] & 0xe0) {
+            goto illegal_request;
+        }
+        if (!check_lba_range(lu, r->req.cmd.lba, len)) {
+            goto illegal_lba;
+        }
+        r->sector = r->req.cmd.lba * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
+        r->sector_count = len * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
+        break;
+    case WRITE_6:
+    case WRITE_10:
+        trace_ufs_scsi_dma_command_WRITE(r->req.cmd.lba, len);
+        if (!blk_is_writable(lu->qdev.conf.blk)) {
+            scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
+            return 0;
+        }
+        if (r->req.cmd.buf[1] & 0xe0) {
+            goto illegal_request;
+        }
+        if (!check_lba_range(lu, r->req.cmd.lba, len)) {
+            goto illegal_lba;
+        }
+        r->sector = r->req.cmd.lba * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
+        r->sector_count = len * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
+        break;
+    default:
+        abort();
+    illegal_request:
+        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
+        return 0;
+    illegal_lba:
+        scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
+        return 0;
+    }
+    r->need_fua_emulation = ((r->req.cmd.buf[1] & 8) != 0);
+    if (r->sector_count == 0) {
+        scsi_req_complete(&r->req, GOOD);
+    }
+    assert(r->iov.iov_len == 0);
+    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+        return -r->sector_count * BDRV_SECTOR_SIZE;
+    } else {
+        return r->sector_count * BDRV_SECTOR_SIZE;
+    }
+}
+
+static void scsi_write_do_fua(UfsSCSIReq *r)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb == NULL);
+    assert(!r->req.io_canceled);
+
+    if (r->need_fua_emulation) {
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
+                         BLOCK_ACCT_FLUSH);
+        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
+        return;
+    }
+
+    scsi_req_complete(&r->req, GOOD);
+    scsi_req_unref(&r->req);
+}
+
+static void scsi_dma_complete_noio(UfsSCSIReq *r, int ret)
+{
+    assert(r->req.aiocb == NULL);
+    if (ufs_scsi_req_check_error(r, ret, false)) {
+        goto done;
+    }
+
+    r->sector += r->sector_count;
+    r->sector_count = 0;
+    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+        scsi_write_do_fua(r);
+        return;
+    } else {
+        scsi_req_complete(&r->req, GOOD);
+    }
+
+done:
+    scsi_req_unref(&r->req);
+}
+
+static void scsi_dma_complete(void *opaque, int ret)
+{
+    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb != NULL);
+    r->req.aiocb = NULL;
+
+    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
+    if (ret < 0) {
+        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    } else {
+        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    }
+    scsi_dma_complete_noio(r, ret);
+    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
+}
+
+static BlockAIOCB *scsi_dma_readv(int64_t offset, QEMUIOVector *iov,
+                                  BlockCompletionFunc *cb, void *cb_opaque,
+                                  void *opaque)
+{
+    UfsSCSIReq *r = opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    return blk_aio_preadv(lu->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
+}
+
+static void scsi_init_iovec(UfsSCSIReq *r, size_t size)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    if (!r->iov.iov_base) {
+        r->buflen = size;
+        r->iov.iov_base = blk_blockalign(lu->qdev.conf.blk, r->buflen);
+    }
+    r->iov.iov_len = MIN(r->sector_count * BDRV_SECTOR_SIZE, r->buflen);
+    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
+}
+
+static void scsi_read_complete_noio(UfsSCSIReq *r, int ret)
+{
+    uint32_t n;
+
+    assert(r->req.aiocb == NULL);
+    if (ufs_scsi_req_check_error(r, ret, false)) {
+        goto done;
+    }
+
+    n = r->qiov.size / BDRV_SECTOR_SIZE;
+    r->sector += n;
+    r->sector_count -= n;
+    scsi_req_data(&r->req, r->qiov.size);
+
+done:
+    scsi_req_unref(&r->req);
+}
+
+static void scsi_read_complete(void *opaque, int ret)
+{
+    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb != NULL);
+    r->req.aiocb = NULL;
+    trace_ufs_scsi_read_data_count(r->sector_count);
+    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
+    if (ret < 0) {
+        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    } else {
+        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+        trace_ufs_scsi_read_complete(r->req.tag, r->qiov.size);
+    }
+    scsi_read_complete_noio(r, ret);
+    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
+}
+
+/* Actually issue a read to the block device.  */
+static void scsi_do_read(UfsSCSIReq *r, int ret)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb == NULL);
+    if (ufs_scsi_req_check_error(r, ret, false)) {
+        goto done;
+    }
+
+    /* The request is used as the AIO opaque value, so add a ref.  */
+    scsi_req_ref(&r->req);
+
+    if (r->req.sg) {
+        dma_acct_start(lu->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_READ);
+        r->req.residual -= r->req.sg->size;
+        r->req.aiocb = dma_blk_io(
+            blk_get_aio_context(lu->qdev.conf.blk), r->req.sg,
+            r->sector << BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE, scsi_dma_readv, r,
+            scsi_dma_complete, r, DMA_DIRECTION_FROM_DEVICE);
+    } else {
+        scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct,
+                         r->qiov.size, BLOCK_ACCT_READ);
+        r->req.aiocb = scsi_dma_readv(r->sector << BDRV_SECTOR_BITS, &r->qiov,
+                                      scsi_read_complete, r, r);
+    }
+
+done:
+    scsi_req_unref(&r->req);
+}
+
+static void scsi_do_read_cb(void *opaque, int ret)
+{
+    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb != NULL);
+    r->req.aiocb = NULL;
+
+    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
+    if (ret < 0) {
+        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    } else {
+        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    }
+    scsi_do_read(opaque, ret);
+    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
+}
+
+/* Read more data from scsi device into buffer.  */
+static void scsi_read_data(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    bool first;
+
+    trace_ufs_scsi_read_data_count(r->sector_count);
+    if (r->sector_count == 0) {
+        /* This also clears the sense buffer for REQUEST SENSE.  */
+        scsi_req_complete(&r->req, GOOD);
+        return;
+    }
+
+    /* No data transfer may already be in progress */
+    assert(r->req.aiocb == NULL);
+
+    /* The request is used as the AIO opaque value, so add a ref.  */
+    scsi_req_ref(&r->req);
+    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+        trace_ufs_scsi_read_data_invalid();
+        scsi_read_complete_noio(r, -EINVAL);
+        return;
+    }
+
+    if (!blk_is_available(req->dev->conf.blk)) {
+        scsi_read_complete_noio(r, -ENOMEDIUM);
+        return;
+    }
+
+    first = !r->started;
+    r->started = true;
+    if (first && r->need_fua_emulation) {
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
+                         BLOCK_ACCT_FLUSH);
+        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_do_read_cb, r);
+    } else {
+        scsi_do_read(r, 0);
+    }
+}
+
+static void scsi_write_complete_noio(UfsSCSIReq *r, int ret)
+{
+    uint32_t n;
+
+    assert(r->req.aiocb == NULL);
+    if (ufs_scsi_req_check_error(r, ret, false)) {
+        goto done;
+    }
+
+    n = r->qiov.size / BDRV_SECTOR_SIZE;
+    r->sector += n;
+    r->sector_count -= n;
+    if (r->sector_count == 0) {
+        scsi_write_do_fua(r);
+        return;
+    } else {
+        scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
+        trace_ufs_scsi_write_complete_noio(r->req.tag, r->qiov.size);
+        scsi_req_data(&r->req, r->qiov.size);
+    }
+
+done:
+    scsi_req_unref(&r->req);
+}
+
+static void scsi_write_complete(void *opaque, int ret)
+{
+    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    assert(r->req.aiocb != NULL);
+    r->req.aiocb = NULL;
+
+    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
+    if (ret < 0) {
+        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    } else {
+        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
+    }
+    scsi_write_complete_noio(r, ret);
+    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
+}
+
+static BlockAIOCB *scsi_dma_writev(int64_t offset, QEMUIOVector *iov,
+                                   BlockCompletionFunc *cb, void *cb_opaque,
+                                   void *opaque)
+{
+    UfsSCSIReq *r = opaque;
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+    return blk_aio_pwritev(lu->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
+}
+
+static void scsi_write_data(SCSIRequest *req)
+{
+    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
+
+    /* No data transfer may already be in progress */
+    assert(r->req.aiocb == NULL);
+
+    /* The request is used as the AIO opaque value, so add a ref.  */
+    scsi_req_ref(&r->req);
+    if (r->req.cmd.mode != SCSI_XFER_TO_DEV) {
+        trace_ufs_scsi_write_data_invalid();
+        scsi_write_complete_noio(r, -EINVAL);
+        return;
+    }
+
+    if (!r->req.sg && !r->qiov.size) {
+        /* Called for the first time.  Ask the driver to send us more data.  */
+        r->started = true;
+        scsi_write_complete_noio(r, 0);
+        return;
+    }
+    if (!blk_is_available(req->dev->conf.blk)) {
+        scsi_write_complete_noio(r, -ENOMEDIUM);
+        return;
+    }
+
+    if (r->req.sg) {
+        dma_acct_start(lu->qdev.conf.blk, &r->acct, r->req.sg,
+                       BLOCK_ACCT_WRITE);
+        r->req.residual -= r->req.sg->size;
+        r->req.aiocb = dma_blk_io(
+            blk_get_aio_context(lu->qdev.conf.blk), r->req.sg,
+            r->sector << BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE, scsi_dma_writev, r,
+            scsi_dma_complete, r, DMA_DIRECTION_TO_DEVICE);
+    } else {
+        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct,
+                         r->qiov.size, BLOCK_ACCT_WRITE);
+        r->req.aiocb = scsi_dma_writev(r->sector << BDRV_SECTOR_BITS, &r->qiov,
+                                       scsi_write_complete, r, r);
+    }
+}
+
+static const SCSIReqOps ufs_scsi_emulate_reqops = {
+    .size = sizeof(UfsSCSIReq),
+    .free_req = ufs_scsi_free_request,
+    .send_command = ufs_scsi_emulate_command,
+    .read_data = ufs_scsi_emulate_read_data,
+    .write_data = ufs_scsi_emulate_write_data,
+    .get_buf = ufs_scsi_get_buf,
+};
+
+static const SCSIReqOps ufs_scsi_dma_reqops = {
+    .size = sizeof(UfsSCSIReq),
+    .free_req = ufs_scsi_free_request,
+    .send_command = ufs_scsi_dma_command,
+    .read_data = scsi_read_data,
+    .write_data = scsi_write_data,
+    .get_buf = ufs_scsi_get_buf,
+};
+
+/*
+ * Following commands are not yet supported
+ * PRE_FETCH(10),
+ * UNMAP,
+ * WRITE_BUFFER, READ_BUFFER,
+ * SECURITY_PROTOCOL_IN, SECURITY_PROTOCOL_OUT
+ */
+static const SCSIReqOps *const ufs_scsi_reqops_dispatch[256] = {
+    [TEST_UNIT_READY] = &ufs_scsi_emulate_reqops,
+    [INQUIRY] = &ufs_scsi_emulate_reqops,
+    [MODE_SENSE_10] = &ufs_scsi_emulate_reqops,
+    [START_STOP] = &ufs_scsi_emulate_reqops,
+    [READ_CAPACITY_10] = &ufs_scsi_emulate_reqops,
+    [REQUEST_SENSE] = &ufs_scsi_emulate_reqops,
+    [SYNCHRONIZE_CACHE] = &ufs_scsi_emulate_reqops,
+    [MODE_SELECT_10] = &ufs_scsi_emulate_reqops,
+    [VERIFY_10] = &ufs_scsi_emulate_reqops,
+    [FORMAT_UNIT] = &ufs_scsi_emulate_reqops,
+    [SERVICE_ACTION_IN_16] = &ufs_scsi_emulate_reqops,
+    [SEND_DIAGNOSTIC] = &ufs_scsi_emulate_reqops,
+
+    [READ_6] = &ufs_scsi_dma_reqops,
+    [READ_10] = &ufs_scsi_dma_reqops,
+    [WRITE_6] = &ufs_scsi_dma_reqops,
+    [WRITE_10] = &ufs_scsi_dma_reqops,
+};
+
+static SCSIRequest *scsi_new_request(SCSIDevice *dev, uint32_t tag,
+                                     uint32_t lun, uint8_t *buf,
+                                     void *hba_private)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);
+    SCSIRequest *req;
+    const SCSIReqOps *ops;
+    uint8_t command;
+
+    command = buf[0];
+    ops = ufs_scsi_reqops_dispatch[command];
+    if (!ops) {
+        ops = &ufs_scsi_emulate_reqops;
+    }
+    req = scsi_req_alloc(ops, &lu->qdev, tag, lun, hba_private);
+
+    return req;
+}
+
+static Property ufs_lu_props[] = {
+    DEFINE_PROP_DRIVE("drive", UfsLu, qdev.conf.blk),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static bool ufs_lu_brdv_init(UfsLu *lu, Error **errp)
+{
+    SCSIDevice *dev = &lu->qdev;
+    bool read_only;
+
+    if (!lu->qdev.conf.blk) {
+        error_setg(errp, "drive property not set");
+        return false;
+    }
+
+    if (!blkconf_blocksizes(&lu->qdev.conf, errp)) {
+        return false;
+    }
+
+    if (blk_get_aio_context(lu->qdev.conf.blk) != qemu_get_aio_context() &&
+        !lu->qdev.hba_supports_iothread) {
+        error_setg(errp, "HBA does not support iothreads");
+        return false;
+    }
+
+    read_only = !blk_supports_write_perm(lu->qdev.conf.blk);
+
+    if (!blkconf_apply_backend_options(&dev->conf, read_only,
+                                       dev->type == TYPE_DISK, errp)) {
+        return false;
+    }
+
+    if (blk_is_sg(lu->qdev.conf.blk)) {
+        error_setg(errp, "unwanted /dev/sg*");
+        return false;
+    }
+
+    blk_iostatus_enable(lu->qdev.conf.blk);
+    return true;
+}
+
+static bool ufs_add_lu(UfsHc *u, UfsLu *lu, Error **errp)
+{
+    BlockBackend *blk = lu->qdev.conf.blk;
+    int64_t brdv_len = blk_getlength(blk);
+    uint64_t raw_dev_cap =
+        be64_to_cpu(u->geometry_desc.total_raw_device_capacity);
+
+    if (u->device_desc.number_lu >= UFS_MAX_LUS) {
+        error_setg(errp, "ufs host controller has too many logical units.");
+        return false;
+    }
+
+    if (u->lus[lu->lun] != NULL) {
+        error_setg(errp, "ufs logical unit %d already exists.", lu->lun);
+        return false;
+    }
+
+    u->lus[lu->lun] = lu;
+    u->device_desc.number_lu++;
+    raw_dev_cap += (brdv_len >> UFS_GEOMETRY_CAPACITY_SHIFT);
+    u->geometry_desc.total_raw_device_capacity = cpu_to_be64(raw_dev_cap);
+    return true;
+}
+
+static inline uint8_t ufs_log2(uint64_t input)
+{
+    int log = 0;
+    while (input >>= 1) {
+        log++;
+    }
+    return log;
+}
+
+static void ufs_init_lu(UfsLu *lu)
+{
+    BlockBackend *blk = lu->qdev.conf.blk;
+    int64_t brdv_len = blk_getlength(blk);
+
+    lu->lun = lu->qdev.lun;
+    memset(&lu->unit_desc, 0, sizeof(lu->unit_desc));
+    lu->unit_desc.length = sizeof(UnitDescriptor);
+    lu->unit_desc.descriptor_idn = UFS_QUERY_DESC_IDN_UNIT;
+    lu->unit_desc.lu_enable = 0x01;
+    lu->unit_desc.logical_block_size = ufs_log2(lu->qdev.blocksize);
+    lu->unit_desc.unit_index = lu->qdev.lun;
+    lu->unit_desc.logical_block_count =
+        cpu_to_be64(brdv_len / (1 << lu->unit_desc.logical_block_size));
+}
+
+static bool ufs_lu_check_constraints(UfsLu *lu, Error **errp)
+{
+    if (!lu->qdev.conf.blk) {
+        error_setg(errp, "drive property not set");
+        return false;
+    }
+
+    if (lu->qdev.channel != 0) {
+        error_setg(errp, "ufs logical unit does not support channel");
+        return false;
+    }
+
+    if (lu->qdev.lun >= UFS_MAX_LUS) {
+        error_setg(errp, "lun must be between 1 and %d", UFS_MAX_LUS - 1);
+        return false;
+    }
+
+    return true;
+}
+
+static void ufs_lu_realize(SCSIDevice *dev, Error **errp)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);
+    BusState *s = qdev_get_parent_bus(&dev->qdev);
+    UfsHc *u = UFS(s->parent);
+    AioContext *ctx = NULL;
+    uint64_t nb_sectors, nb_blocks;
+
+    if (!ufs_lu_check_constraints(lu, errp)) {
+        return;
+    }
+
+    if (lu->qdev.conf.blk) {
+        ctx = blk_get_aio_context(lu->qdev.conf.blk);
+        aio_context_acquire(ctx);
+        if (!blkconf_blocksizes(&lu->qdev.conf, errp)) {
+            goto out;
+        }
+    }
+    lu->qdev.blocksize = UFS_BLOCK_SIZE;
+    blk_get_geometry(lu->qdev.conf.blk, &nb_sectors);
+    nb_blocks = nb_sectors / (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
+    if (nb_blocks > UINT32_MAX) {
+        nb_blocks = UINT32_MAX;
+    }
+    lu->qdev.max_lba = nb_blocks;
+    lu->qdev.type = TYPE_DISK;
+
+    ufs_init_lu(lu);
+    if (!ufs_add_lu(u, lu, errp)) {
+        goto out;
+    }
+
+    ufs_lu_brdv_init(lu, errp);
+out:
+    if (ctx) {
+        aio_context_release(ctx);
+    }
+}
+
+static void ufs_lu_unrealize(SCSIDevice *dev)
+{
+    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);
+
+    blk_drain(lu->qdev.conf.blk);
+}
+
+static void ufs_wlu_realize(DeviceState *qdev, Error **errp)
+{
+    UfsWLu *wlu = UFSWLU(qdev);
+    SCSIDevice *dev = &wlu->qdev;
+
+    if (!is_wlun(dev->lun)) {
+        error_setg(errp, "not well-known logical unit number");
+        return;
+    }
+
+    QTAILQ_INIT(&dev->requests);
+}
+
+static void ufs_lu_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    SCSIDeviceClass *sc = SCSI_DEVICE_CLASS(oc);
+
+    sc->realize = ufs_lu_realize;
+    sc->unrealize = ufs_lu_unrealize;
+    sc->alloc_req = scsi_new_request;
+    dc->bus_type = TYPE_UFS_BUS;
+    device_class_set_props(dc, ufs_lu_props);
+    dc->desc = "Virtual UFS logical unit";
+}
+
+static void ufs_wlu_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    SCSIDeviceClass *sc = SCSI_DEVICE_CLASS(oc);
+
+    /*
+     * The realize() function of TYPE_SCSI_DEVICE causes a segmentation fault
+     * if a block drive does not exist. Define a new realize function for
+     * well-known LUs that do not have a block drive.
+     */
+    dc->realize = ufs_wlu_realize;
+    sc->alloc_req = scsi_new_request;
+    dc->bus_type = TYPE_UFS_BUS;
+    dc->desc = "Virtual UFS well-known logical unit";
+}
+
+static const TypeInfo ufs_lu_info = {
+    .name = TYPE_UFS_LU,
+    .parent = TYPE_SCSI_DEVICE,
+    .class_init = ufs_lu_class_init,
+    .instance_size = sizeof(UfsLu),
+};
+
+static const TypeInfo ufs_wlu_info = {
+    .name = TYPE_UFS_WLU,
+    .parent = TYPE_SCSI_DEVICE,
+    .class_init = ufs_wlu_class_init,
+    .instance_size = sizeof(UfsWLu),
+};
+
+static void ufs_lu_register_types(void)
+{
+    type_register_static(&ufs_lu_info);
+    type_register_static(&ufs_wlu_info);
+}
+
+type_init(ufs_lu_register_types)