Commit 604dfaaa authored by Fam Zheng's avatar Fam Zheng Committed by Stefan Hajnoczi
Browse files

iscsi: Implement copy offloading 



Issue EXTENDED COPY (LID1) command to implement the copy_range API.

The parameter data construction code is modified from libiscsi's
iscsi-dd.c.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180601092648.24614-9-famz@redhat.com
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 66e75c03

block/iscsi.c

+219 −0
Original line number Diff line number Diff line
@@ -2205,6 +2205,221 @@ static void coroutine_fn iscsi_co_invalidate_cache(BlockDriverState *bs, 
    iscsi_allocmap_invalidate(iscsilun);

}



static int coroutine_fn iscsi_co_copy_range_from(BlockDriverState *bs,

                                                 BdrvChild *src,

                                                 uint64_t src_offset,

                                                 BdrvChild *dst,

                                                 uint64_t dst_offset,

                                                 uint64_t bytes,

                                                 BdrvRequestFlags flags)

{

    return bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes, flags);

}



static struct scsi_task *iscsi_xcopy_task(int param_len)

{

    struct scsi_task *task;



    task = g_new0(struct scsi_task, 1);



    task->cdb[0]     = EXTENDED_COPY;

    task->cdb[10]    = (param_len >> 24) & 0xFF;

    task->cdb[11]    = (param_len >> 16) & 0xFF;

    task->cdb[12]    = (param_len >> 8) & 0xFF;

    task->cdb[13]    = param_len & 0xFF;

    task->cdb_size   = 16;

    task->xfer_dir   = SCSI_XFER_WRITE;

    task->expxferlen = param_len;



    return task;

}



static void iscsi_populate_target_desc(unsigned char *desc, IscsiLun *lun)

{

    struct scsi_inquiry_device_designator *dd = lun->dd;



    memset(desc, 0, 32);

    desc[0] = 0xE4; /* IDENT_DESCR_TGT_DESCR */

    desc[4] = dd->code_set;

    desc[5] = (dd->designator_type & 0xF)

        | ((dd->association & 3) << 4);

    desc[7] = dd->designator_length;

    memcpy(desc + 8, dd->designator, dd->designator_length);



    desc[28] = 0;

    desc[29] = (lun->block_size >> 16) & 0xFF;

    desc[30] = (lun->block_size >> 8) & 0xFF;

    desc[31] = lun->block_size & 0xFF;

}



static void iscsi_xcopy_desc_hdr(uint8_t *hdr, int dc, int cat, int src_index,

                                 int dst_index)

{

    hdr[0] = 0x02; /* BLK_TO_BLK_SEG_DESCR */

    hdr[1] = ((dc << 1) | cat) & 0xFF;

    hdr[2] = (XCOPY_BLK2BLK_SEG_DESC_SIZE >> 8) & 0xFF;

    /* don't account for the first 4 bytes in descriptor header*/

    hdr[3] = (XCOPY_BLK2BLK_SEG_DESC_SIZE - 4 /* SEG_DESC_SRC_INDEX_OFFSET */) & 0xFF;

    hdr[4] = (src_index >> 8) & 0xFF;

    hdr[5] = src_index & 0xFF;

    hdr[6] = (dst_index >> 8) & 0xFF;

    hdr[7] = dst_index & 0xFF;

}



static void iscsi_xcopy_populate_desc(uint8_t *desc, int dc, int cat,

                                      int src_index, int dst_index, int num_blks,

                                      uint64_t src_lba, uint64_t dst_lba)

{

    iscsi_xcopy_desc_hdr(desc, dc, cat, src_index, dst_index);



    /* The caller should verify the request size */

    assert(num_blks < 65536);

    desc[10] = (num_blks >> 8) & 0xFF;

    desc[11] = num_blks & 0xFF;

    desc[12] = (src_lba >> 56) & 0xFF;

    desc[13] = (src_lba >> 48) & 0xFF;

    desc[14] = (src_lba >> 40) & 0xFF;

    desc[15] = (src_lba >> 32) & 0xFF;

    desc[16] = (src_lba >> 24) & 0xFF;

    desc[17] = (src_lba >> 16) & 0xFF;

    desc[18] = (src_lba >> 8) & 0xFF;

    desc[19] = src_lba & 0xFF;

    desc[20] = (dst_lba >> 56) & 0xFF;

    desc[21] = (dst_lba >> 48) & 0xFF;

    desc[22] = (dst_lba >> 40) & 0xFF;

    desc[23] = (dst_lba >> 32) & 0xFF;

    desc[24] = (dst_lba >> 24) & 0xFF;

    desc[25] = (dst_lba >> 16) & 0xFF;

    desc[26] = (dst_lba >> 8) & 0xFF;

    desc[27] = dst_lba & 0xFF;

}



static void iscsi_xcopy_populate_header(unsigned char *buf, int list_id, int str,

                                        int list_id_usage, int prio,

                                        int tgt_desc_len,

                                        int seg_desc_len, int inline_data_len)

{

    buf[0] = list_id;

    buf[1] = ((str & 1) << 5) | ((list_id_usage & 3) << 3) | (prio & 7);

    buf[2] = (tgt_desc_len >> 8) & 0xFF;

    buf[3] = tgt_desc_len & 0xFF;

    buf[8] = (seg_desc_len >> 24) & 0xFF;

    buf[9] = (seg_desc_len >> 16) & 0xFF;

    buf[10] = (seg_desc_len >> 8) & 0xFF;

    buf[11] = seg_desc_len & 0xFF;

    buf[12] = (inline_data_len >> 24) & 0xFF;

    buf[13] = (inline_data_len >> 16) & 0xFF;

    buf[14] = (inline_data_len >> 8) & 0xFF;

    buf[15] = inline_data_len & 0xFF;

}



static void iscsi_xcopy_data(struct iscsi_data *data,

                             IscsiLun *src, int64_t src_lba,

                             IscsiLun *dst, int64_t dst_lba,

                             uint16_t num_blocks)

{

    uint8_t *buf;

    const int src_offset = XCOPY_DESC_OFFSET;

    const int dst_offset = XCOPY_DESC_OFFSET + IDENT_DESCR_TGT_DESCR_SIZE;

    const int seg_offset = dst_offset + IDENT_DESCR_TGT_DESCR_SIZE;



    data->size = XCOPY_DESC_OFFSET +

                 IDENT_DESCR_TGT_DESCR_SIZE * 2 +

                 XCOPY_BLK2BLK_SEG_DESC_SIZE;

    data->data = g_malloc0(data->size);

    buf = data->data;



    /* Initialise the parameter list header */

    iscsi_xcopy_populate_header(buf, 1, 0, 2 /* LIST_ID_USAGE_DISCARD */,

                                0, 2 * IDENT_DESCR_TGT_DESCR_SIZE,

                                XCOPY_BLK2BLK_SEG_DESC_SIZE,

                                0);



    /* Initialise CSCD list with one src + one dst descriptor */

    iscsi_populate_target_desc(&buf[src_offset], src);

    iscsi_populate_target_desc(&buf[dst_offset], dst);



    /* Initialise one segment descriptor */

    iscsi_xcopy_populate_desc(&buf[seg_offset], 0, 0, 0, 1, num_blocks,

                              src_lba, dst_lba);

}



static int coroutine_fn iscsi_co_copy_range_to(BlockDriverState *bs,

                                               BdrvChild *src,

                                               uint64_t src_offset,

                                               BdrvChild *dst,

                                               uint64_t dst_offset,

                                               uint64_t bytes,

                                               BdrvRequestFlags flags)

{

    IscsiLun *dst_lun = dst->bs->opaque;

    IscsiLun *src_lun;

    struct IscsiTask iscsi_task;

    struct iscsi_data data;

    int r = 0;

    int block_size;



    if (src->bs->drv->bdrv_co_copy_range_to != iscsi_co_copy_range_to) {

        return -ENOTSUP;

    }

    src_lun = src->bs->opaque;



    if (!src_lun->dd || !dst_lun->dd) {

        return -ENOTSUP;

    }

    if (!is_byte_request_lun_aligned(dst_offset, bytes, dst_lun)) {

        return -ENOTSUP;

    }

    if (!is_byte_request_lun_aligned(src_offset, bytes, src_lun)) {

        return -ENOTSUP;

    }

    if (dst_lun->block_size != src_lun->block_size ||

        !dst_lun->block_size) {

        return -ENOTSUP;

    }



    block_size = dst_lun->block_size;

    if (bytes / block_size > 65535) {

        return -ENOTSUP;

    }



    iscsi_xcopy_data(&data,

                     src_lun, src_offset / block_size,

                     dst_lun, dst_offset / block_size,

                     bytes / block_size);



    iscsi_co_init_iscsitask(dst_lun, &iscsi_task);



    qemu_mutex_lock(&dst_lun->mutex);

    iscsi_task.task = iscsi_xcopy_task(data.size);

retry:

    if (iscsi_scsi_command_async(dst_lun->iscsi, dst_lun->lun,

                                 iscsi_task.task, iscsi_co_generic_cb,

                                 &data,

                                 &iscsi_task) != 0) {

        r = -EIO;

        goto out_unlock;

    }



    iscsi_co_wait_for_task(&iscsi_task, dst_lun);



    if (iscsi_task.do_retry) {

        iscsi_task.complete = 0;

        goto retry;

    }



    if (iscsi_task.status != SCSI_STATUS_GOOD) {

        r = iscsi_task.err_code;

        goto out_unlock;

    }



out_unlock:

    g_free(iscsi_task.task);

    qemu_mutex_unlock(&dst_lun->mutex);

    g_free(iscsi_task.err_str);

    return r;

}



static QemuOptsList iscsi_create_opts = {

    .name = "iscsi-create-opts",

    .head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
@@ -2239,6 +2454,8 @@ static BlockDriver bdrv_iscsi = { 


    .bdrv_co_block_status  = iscsi_co_block_status,

    .bdrv_co_pdiscard      = iscsi_co_pdiscard,

    .bdrv_co_copy_range_from = iscsi_co_copy_range_from,

    .bdrv_co_copy_range_to  = iscsi_co_copy_range_to,

    .bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,

    .bdrv_co_readv         = iscsi_co_readv,

    .bdrv_co_writev        = iscsi_co_writev,
@@ -2274,6 +2491,8 @@ static BlockDriver bdrv_iser = { 


    .bdrv_co_block_status  = iscsi_co_block_status,

    .bdrv_co_pdiscard      = iscsi_co_pdiscard,

    .bdrv_co_copy_range_from = iscsi_co_copy_range_from,

    .bdrv_co_copy_range_to  = iscsi_co_copy_range_to,

    .bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,

    .bdrv_co_readv         = iscsi_co_readv,

    .bdrv_co_writev        = iscsi_co_writev,

include/scsi/constants.h

+4 −0
Original line number Diff line number Diff line
@@ -311,4 +311,8 @@ 
#define MMC_PROFILE_HDDVD_RW_DL         0x005A

#define MMC_PROFILE_INVALID             0xFFFF



#define XCOPY_DESC_OFFSET 16

#define IDENT_DESCR_TGT_DESCR_SIZE 32

#define XCOPY_BLK2BLK_SEG_DESC_SIZE 28



#endif