This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] [patch 0/2] Fix rawhide FV booting on VMX

To: "Stephen C. Tweedie" <sct@xxxxxxxxxx>
Subject: Re: [Xen-devel] [patch 0/2] Fix rawhide FV booting on VMX
From: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Date: Wed, 23 May 2007 17:12:32 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Wed, 23 May 2007 09:10:52 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <1179848292.8438.40.camel@xxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <1179848292.8438.40.camel@xxxxxxxxxxxxxxxxxxxxx>
Reply-to: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.1i
On Tue, May 22, 2007 at 04:38:12PM +0100, Stephen C. Tweedie wrote:
> So the fix here is to first of all extend the virtual PIC provided by
> the hypervisor, supporting a new 2-byte control sequence which lets the
> guests change the interrupt vectors _without_ fully reinitialising the
> vPIC; and secondly to have vmxassist use that sequence to reset the vPIC
> vectors appropriately whenever we transition between 16 and 32-bit mode.
> This has been verified to allow rawhide installs to proceed under Xen
> FV.  

I've tested that with this patch applied, Xen 3.1.0 is able to succesfully
boot  RHEL-3, RHEL-4, RHEL-5, both i386 & x86_64  fullyvirt, and also
Mandriva CS-4 boots. SuSE 10.1 still black screens with / without this
patch. So on the whole it seems to be an improvement, with no regressions
I've found yet.

> Points for discussion:
> * Do we need/want vmxassist to fail gracefully if the enhanced vPIC
> sequence is not available?
> * Is the magic sequence used here (0xff written to ICW1) genuinely
> impossible for other guests to use? (see patch 1/2 to follow.)

|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
|=-           Perl modules: http://search.cpan.org/~danberr/              -=|
|=-               Projects: http://freshmeat.net/~danielpb/               -=|
|=-  GnuPG: 7D3B9505   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505  -=| 

Xen-devel mailing list