Re: [Qemu-devel] [PATCH v3 07/29] block: rename buffer_alignment to guest_block_size

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Friday 17 Jan 2014 à 15:14:57 (+0100), Kevin Wolf a écrit :
> From: Paolo Bonzini <pbonzini@redhat.com>
> 
> The alignment field is now set to the value that is promised to the
> guest, rather than required by the host.  The next patches will make
> QEMU aware of the host-provided values, so make this clear.
> 
> The alignment is also not about memory buffers, but about the sectors on
> the disk, change the documentation of the field.
> 
> At this point, the field is set by the device emulation, but completely
> ignored by the block layer.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c                   | 10 +++++-----
>  hw/block/virtio-blk.c     |  2 +-
>  hw/ide/core.c             |  2 +-
>  hw/scsi/scsi-disk.c       |  2 +-
>  hw/scsi/scsi-generic.c    |  2 +-
>  include/block/block.h     |  2 +-
>  include/block/block_int.h |  4 ++--
>  7 files changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 04c409a..b738abe 100644
> --- a/block.c
> +++ b/block.c
> @@ -812,7 +812,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
>      }
>  
>      bs->open_flags = flags;
> -    bs->buffer_alignment = 512;
> +    bs->guest_block_size = 512;
>      bs->zero_beyond_eof = true;
>      open_flags = bdrv_open_flags(bs, flags);
>      bs->read_only = !(open_flags & BDRV_O_RDWR);
> @@ -1648,7 +1648,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
>      bs_dest->dev_ops            = bs_src->dev_ops;
>      bs_dest->dev_opaque         = bs_src->dev_opaque;
>      bs_dest->dev                = bs_src->dev;
> -    bs_dest->buffer_alignment   = bs_src->buffer_alignment;
> +    bs_dest->guest_block_size   = bs_src->guest_block_size;
>      bs_dest->copy_on_read       = bs_src->copy_on_read;
>  
>      bs_dest->enable_write_cache = bs_src->enable_write_cache;
> @@ -1800,7 +1800,7 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev)
>      bs->dev = NULL;
>      bs->dev_ops = NULL;
>      bs->dev_opaque = NULL;
> -    bs->buffer_alignment = 512;
> +    bs->guest_block_size = 512;
>  }
>  
>  /* TODO change to return DeviceState * when all users are qdevified */
> @@ -4561,9 +4561,9 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
>      return NULL;
>  }
>  
> -void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
> +void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
>  {
> -    bs->buffer_alignment = align;
> +    bs->guest_block_size = align;
>  }
>  
>  void *qemu_blockalign(BlockDriverState *bs, size_t size)
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 19d0961..8a568e5 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -731,7 +731,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
>      register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
>                      virtio_blk_save, virtio_blk_load, s);
>      bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
> -    bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);
> +    bdrv_set_guest_block_size(s->bs, s->conf->logical_block_size);
>  
>      bdrv_iostatus_enable(s->bs);
>  
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index e1f4c33..036cd4a 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -2103,7 +2103,7 @@ int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,
>      s->smart_selftest_count = 0;
>      if (kind == IDE_CD) {
>          bdrv_set_dev_ops(bs, &ide_cd_block_ops, s);
> -        bdrv_set_buffer_alignment(bs, 2048);
> +        bdrv_set_guest_block_size(bs, 2048);
>      } else {
>          if (!bdrv_is_inserted(s->bs)) {
>              error_report("Device needs media, but drive is empty");
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index bce617c..6491091 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -2254,7 +2254,7 @@ static int scsi_initfn(SCSIDevice *dev)
>      } else {
>          bdrv_set_dev_ops(s->qdev.conf.bs, &scsi_disk_block_ops, s);
>      }
> -    bdrv_set_buffer_alignment(s->qdev.conf.bs, s->qdev.blocksize);
> +    bdrv_set_guest_block_size(s->qdev.conf.bs, s->qdev.blocksize);
>  
>      bdrv_iostatus_enable(s->qdev.conf.bs);
>      add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, NULL);
> diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
> index 8f195be..f08b64e 100644
> --- a/hw/scsi/scsi-generic.c
> +++ b/hw/scsi/scsi-generic.c
> @@ -210,7 +210,7 @@ static void scsi_read_complete(void * opaque, int ret)
>              s->blocksize = ldl_be_p(&r->buf[8]);
>              s->max_lba = ldq_be_p(&r->buf[0]);
>          }
> -        bdrv_set_buffer_alignment(s->conf.bs, s->blocksize);
> +        bdrv_set_guest_block_size(s->conf.bs, s->blocksize);
>  
>          scsi_req_data(&r->req, len);
>          if (!r->req.io_canceled) {
> diff --git a/include/block/block.h b/include/block/block.h
> index cf63ee2..05252d5 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -422,7 +422,7 @@ void bdrv_img_create(const char *filename, const char *fmt,
>  /* Returns the alignment in bytes that is required so that no bounce buffer
>   * is required throughout the stack */
>  size_t bdrv_opt_mem_align(BlockDriverState *bs);
> -void bdrv_set_buffer_alignment(BlockDriverState *bs, int align);
> +void bdrv_set_guest_block_size(BlockDriverState *bs, int align);
>  void *qemu_blockalign(BlockDriverState *bs, size_t size);
>  bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
>  
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index a602e14..36c068f 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -319,8 +319,8 @@ struct BlockDriverState {
>      /* Whether produces zeros when read beyond eof */
>      bool zero_beyond_eof;
>  
> -    /* the memory alignment required for the buffers handled by this driver */
> -    int buffer_alignment;
> +    /* the block size for which the guest device expects atomicity */
> +    int guest_block_size;
>  
>      /* do we need to tell the quest if we have a volatile write cache? */
>      int enable_write_cache;
> -- 
> 1.8.1.4
> 
> 

Reviewed-by: Benoit Canet <benoit@irqsave.net>