Re: [PATCH RFC 2/4] build: Download and build extnernal blktap2.5 repo

[George Dunlap <george.dunlap@eu.citrix.com>]

On 03/30/2015 03:41 PM, Ian Campbell wrote:
> On Mon, 2015-03-30 at 15:33 +0100, Wei Liu wrote:
>> On Thu, Mar 26, 2015 at 12:46:08PM +0000, George Dunlap wrote:
>>> Download and build XenServer's blktap as an external tree, similar to
>>> qemu-xen.
>>>
>>> As of this patch we just download and build it, but don't install or
>>> use it.
>>>
>>> Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
>>> ---
>>>
>>> FIXME: Directly use the XenServer github repo for now, while we're
>>> discussing things.  If we decide to take this series, we'll have to
>>> clone the tree on xenbits and remove the FIXME line.
>>>
>>
>> IMHO we need to support --with-system-blktap= in configure in case
>> distro wants to package blktap separately. Not sure if in practice this
>> makes sense since AIUI blktap is only used by Xen.
> 
> I think you are right, there are at least some distros which ship a
> blktap package not from Xen. e.g. Debian ship, or have in the past
> shipped, the blktap2.5 packages.

Bob has said that Fedora ship a blktap2.5 package that can't actually be
installed at the same time as the Fedora xen packages, making it
somewhat useless...

> blktap is a bit different to some of the other similar cases though in
> that there is a circular dependency, although George indicated last week
> that he thought that might be an easily fixed one.

I suspect this has probably already been fixed in blktap2.5, since (I'm
pretty sure) XenServer ship blktap and the things that depend on it
(like xen and xapi) in separate rpms; but it's certainly something we'd
have to look at.

 -George