hw/block/virtio-blk-common.c

   1 /*
   2  * Virtio Block Device common helpers
   3  *
   4  * Copyright IBM, Corp. 2007
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qemu/osdep.h"
  14
  15 #include "standard-headers/linux/virtio_blk.h"
  16 #include "hw/virtio/virtio.h"
  17 #include "hw/virtio/virtio-blk-common.h"
  18
  19 /* Config size before the discard support (hide associated config fields) */
  20 #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
  21                                      max_discard_sectors)
  22
  23 /*
  24  * Starting from the discard feature, we can use this array to properly
  25  * set the config size depending on the features enabled.
  26  */
  27 static const VirtIOFeature feature_sizes[] = {
  28     {.flags = 1ULL << VIRTIO_BLK_F_DISCARD,
  29      .end = endof(struct virtio_blk_config, discard_sector_alignment)},
  30     {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES,
  31      .end = endof(struct virtio_blk_config, write_zeroes_may_unmap)},
  32     {}
  33 };
  34
  35 const VirtIOConfigSizeParams virtio_blk_cfg_size_params = {
  36     .min_size = VIRTIO_BLK_CFG_SIZE,
  37     .max_size = sizeof(struct virtio_blk_config),
  38     .feature_sizes = feature_sizes
  39 };