Re: [Xen-devel] Problems with 'xl create winxp' (hvm) on xen 4.1.2 (also affects GPLPV)

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2011-10-31 at 10:50 +0000, Ian Campbell wrote:
> On Sat, 2011-10-29 at 06:57 +0100, jim burns wrote:
> > Setup:
> > 
> > Fedora 15, w/f16's 3.1.0 (also tried 2.6.40 & 3.0.0)
> > xen 4.1.2 (newly upgraded from 4.1.1, from rawhide)
> > 
> > Since the release notes for 4.1.2 said, in part:
> > 
> > Fixes/features include:
> >  * New XL toolstack
> > 
> > I decided to test some problems I saw using xl to start a winxp hvm domu 
> > under 
> > xen 4.1.1, and found that they were still there, and I came up with a 
> > somewhat 
> > more serious one as well. I'm sure that others can point out more serious 
> > problems, but these are the ones that affect me. In all cases, 'xm create' 
> > does not have these problems. Domu config at the end of the post.
> > 
> > New to 4.1.2:
> > 
> > 1) Starting winxp with xl does not create a vif interface - only a tap one. 
> > More exactly, the vif is created, but does not get an ipv6 address - it 
> > shows 
> > up in 'ifconfig -a', or 'ifconfig vifn.0' - and does not get added to the 
> > bridge. If you are using James' GPLPV drivers, you end up with no network 
> > connectivity, as they use vif, not tap. I'd be surprised if other pvhvm 
> > solutions don't see this also.
> 
> I see this with the tip of xen-4.1-testing too but not with
> xen-unstable. I'll see if I can figure out which backport is missing...

23047:4ca13a170482 "libxl: provide full path to vif hotplug script
script" seems like a very plausible candidate, I bet
"script=/etc/xen/scripts/vif-bridge" would function as a workaround.

> [...]
> > 2) If your vif= line in your config specifies a bridge, such as 
> > 'bridge=virbr0', the '-net tap' option to qemu-dm remains as 
> > 'bridge=xenbr0', 
> > as if it was hard coded. Again, this is an hvm problem. 'xl create'-ing a 
> > pv 
> > domu correctly puts the vif on the requested bridge. (If memory serves, 
> > under 
> > xen 4.1.1, when the vif for an hvm domain was being put on a bridge, I 
> > believe 
> > it was on the bridge requested, so the problem is just with tap.)
> 
> Similarly I can reproduce this too but only on 4.1.

Actually this one is broken in unstable too.

The handling of leading and trailing whitespace in the vif option seems
to be completely b0rked in xl and e.g. "bridge = virbr1" ends up as key
"bridge " and key " virbr1". That entire parser (actually, both of them
-- there's a whole nother one in main_networkattach!) is a mess.

There's probably a bandaid which can be applied but really the whole
thing need ripping out and making sensible.

As a workaround in the meantime you can probably avoid whitespace around
the "=" and "," in the vif line.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel