Commit 4397a018 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

scsi: support NDOB (no data-out buffer) for WRITE SAME commands 



A NDOB bit set to one specifies that the disk shall not transfer data
from the data-out buffer and shall process the command as if the data-out
buffer contained user data set to all zeroes.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 05b6cc4a

hw/scsi/scsi-bus.c

+1 −1
Original line number Diff line number Diff line
@@ -944,7 +944,7 @@ static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf) 
        break;

    case WRITE_SAME_10:

    case WRITE_SAME_16:

        cmd->xfer = dev->blocksize;

        cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;

        break;

    case READ_CAPACITY_10:

        cmd->xfer = 8;

hw/scsi/scsi-disk.c

+1 −1
Original line number Diff line number Diff line
@@ -1807,7 +1807,7 @@ static void scsi_disk_emulate_write_same(SCSIDiskReq *r, uint8_t *inbuf) 
        return;

    }



    if (buffer_is_zero(inbuf, s->qdev.blocksize)) {

    if ((req->cmd.buf[1] & 0x1) || buffer_is_zero(inbuf, s->qdev.blocksize)) {

        int flags = (req->cmd.buf[1] & 0x8) ? BDRV_REQ_MAY_UNMAP : 0;



        /* The request is used as the AIO opaque value, so add a ref.  */

tests/virtio-scsi-test.c

+6 −0
Original line number Diff line number Diff line
@@ -216,6 +216,9 @@ static void test_unaligned_write_same(void) 
    const uint8_t write_same_cdb_2[VIRTIO_SCSI_CDB_SIZE] = {

        0x41, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x33, 0x00, 0x00

    };

    const uint8_t write_same_cdb_ndob[VIRTIO_SCSI_CDB_SIZE] = {

        0x41, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x33, 0x00, 0x00

    };



    vs = qvirtio_scsi_pci_init(PCI_SLOT);
@@ -225,6 +228,9 @@ static void test_unaligned_write_same(void) 
    g_assert_cmphex(0, ==,

        virtio_scsi_do_command(vs, write_same_cdb_2, NULL, 0, buf2, 512, NULL));



    g_assert_cmphex(0, ==,

        virtio_scsi_do_command(vs, write_same_cdb_ndob, NULL, 0, NULL, 0, NULL));



    qvirtio_scsi_pci_free(vs);

}