Re: [HVM} xen_platform_pci=0 doesn't prevent platform device creation and disk and nic take over by PV drivers.

From: George Dunlap <George.Dunlap@eu.citrix.com>
To: Sander Eikelenboom <linux@eikelenboom.it>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Lars Kurth <lars.kurth.xen@gmail.com>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
	Anthony Perard <anthony.perard@citrix.com>
Subject: Re: [HVM} xen_platform_pci=0 doesn't prevent platform device creation and disk and nic take over by PV drivers.
Date: Thu, 10 Oct 2013 11:03:34 +0100	[thread overview]
Message-ID: <CAFLBxZY5qN+e0J9j0ttQLb4aci08fbMvPE3TC73adC8enZf3Uw@mail.gmail.com> (raw)
In-Reply-To: <1043931136.20131009144924@eikelenboom.it>

On Wed, Oct 9, 2013 at 1:49 PM, Sander Eikelenboom <linux@eikelenboom.it> wrote:
>
> Wednesday, October 9, 2013, 2:00:02 PM, you wrote:
>
>> create ^
>> title it xen_platform_pci=0 doesn't work with qemu-xen
>> owner it Anthony Perard <anthony.perard@citrix.com>
>> thanks
>
> Perhaps in general looking at the libxl and xend .. and .. qemu-xen and qemu-xen-traditonal compatibility shoud be added too.
>
> Perhaps i'm a bit blunt ..
> but for users it's quite a mess and PITA now for quite some time, the transition of both is now smeared out over quite some major and minor releases.
>
> With some features not working since .. some features are working again but have a gap of not working,
> since old features becoming usable again are (understandably) not backported.
>
> This seems to be at a level that it is even undocumentable ... you would need a spreadsheet
> with every minor version to try to document that ... it seems to be leading to a lot of user questions as well.
>
> I'm not blaming any one personally or anything like that .. just expressing my worries and the threat i see for Xen as a project in general.
> Namely users sop
>
> I understand that new features like the arm port are interesting .. but i think that has the cost of both
> IanC and Stefano time to work on libxl and qemu-upstream seems to be quite limited, and perhaps developer time in general is.

FWIW, the ARM stuff isn't just "interesting" -- it was a critical
strategic opportunity for the future of the Xen project.  The work
that was done, particularly the political stuff done by Stefano to get
Xen into Linaro, was a major achievement at just the right time.  A
delay of even a few months may have meant that Xen had basically no
presence in ARM server space, which would in turn have had an impact
on the commercial viability of the Xen project as a whole.  The vast
majority of the money used to support Xen comes from the server
market.  Growing this market means more commercial interest in Xen,
which means more developers; missing this market could have knock-on
effects in the x86 space, which would have had a much bigger impact on
PCI pass-through in the long term.

 -George