hw/scsi/emulation.c

   1 #include "qemu/osdep.h"
   2 #include "qemu/units.h"
   3 #include "qemu/bswap.h"
   4 #include "hw/scsi/emulation.h"
   5
   6 int scsi_emulate_block_limits(uint8_t *outbuf, const SCSIBlockLimits *bl)
   7 {
   8     /* required VPD size with unmap support */
   9     memset(outbuf, 0, 0x3c);
  10
  11     outbuf[0] = bl->wsnz; /* wsnz */
  12
  13     if (bl->max_io_sectors) {
  14         /* optimal transfer length granularity.  This field and the optimal
  15          * transfer length can't be greater than maximum transfer length.
  16          */
  17         stw_be_p(outbuf + 2, MIN(bl->min_io_size, bl->max_io_sectors));
  18
  19         /* maximum transfer length */
  20         stl_be_p(outbuf + 4, bl->max_io_sectors);
  21
  22         /* optimal transfer length */
  23         stl_be_p(outbuf + 8, MIN(bl->opt_io_size, bl->max_io_sectors));
  24     } else {
  25         stw_be_p(outbuf + 2, bl->min_io_size);
  26         stl_be_p(outbuf + 8, bl->opt_io_size);
  27     }
  28
  29     /* max unmap LBA count */
  30     stl_be_p(outbuf + 16, bl->max_unmap_sectors);
  31
  32     /* max unmap descriptors */
  33     stl_be_p(outbuf + 20, bl->max_unmap_descr);
  34
  35     /* optimal unmap granularity; alignment is zero */
  36     stl_be_p(outbuf + 24, bl->unmap_sectors);
  37
  38     /* max write same size, make it the same as maximum transfer length */
  39     stl_be_p(outbuf + 36, bl->max_io_sectors);
  40
  41     return 0x3c;
  42 }