Re: [Qemu-devel] [PATCH] tcm_vhost: Expose ABI version via VHOST_SCSI_GET_ABI_VERSION

[Nicholas A. Bellinger]

On Thu, 2012-07-26 at 11:58 +0300, Avi Kivity wrote:
> On 07/26/2012 05:34 AM, Nicholas A. Bellinger wrote:
> > 
> > In that case, respinning a -v5 for tcm_vhost to start from ABI=0 and
> > will post an updated patch shortly.
> > 
> >> The main thing I would like to confirm is that this only versions the
> >> tcm_vhost ioctls?  In that case a single version number works.
> >> 
> > 
> > Correct, the GET_ABI_VERSION call is only intended to identify the
> > changing of tcm_vhost ioctls.
> 
> Why use version numbers at all?
> 

This was a request by QEMU folks.. 


> Feature maps are better, because you can get very fine granularity.
> 
> 

Example..?  If there is a better way to handle ioctl compat I'd
certainly like to hear about it.