Re: [Qemu-devel] [PATCH 4/4] blocksize: add blkconf_blocksize call to all block devices

[Stefan Hajnoczi]

On Tue, Jul 29, 2014 at 02:27:19PM +0200, Ekaterina Tumanova wrote:
> This patch add the blkconf_blocksize call to all
> devices, which use DEFINE_BLOCK_PROPERTIES.
> If the underlying driver function fails, blkconf_blocksizes
> will set blocksizes to default (512) value.
> 
> Signed-off-by: Ekaterina Tumanova <address@hidden>
> Reviewed-by: David Hildenbrand <address@hidden>
> Acked-by: Cornelia Huck <address@hidden>
> ---
>  hw/block/nvme.c          | 1 +
>  hw/block/virtio-blk.c    | 1 +
>  hw/ide/qdev.c            | 1 +
>  hw/scsi/scsi-disk.c      | 1 +
>  hw/usb/dev-storage.c     | 1 +
>  include/hw/block/block.h | 4 ++--
>  6 files changed, 7 insertions(+), 2 deletions(-)

Wasn't this NACKed before on the grounds that it is likely to upset the
guest after live migration?  QEMU doesn't automatically query the
storage because these parameters must be preserved across migration.

The knowledge of these fields belongs in the management tool that
orchestrates migration, not QEMU.

If you want specific parameters, please put them in your guest
configuration.  QEMU and libvirt support that.

I'm concerned that this patch serious is likely to break things and
autodetection doesn't add much value since the management tool needs to
be aware of this information anyway.

Stefan

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