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From: Keir Fraser <keir@xen.org>
To: "Christopher S. Aker" <caker@theshore.net>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	xen devel <xen-devel@lists.xensource.com>
Subject: Re: Xen 4 serial hangs during boot
Date: Fri, 20 Jul 2012 20:59:29 +0100	[thread overview]
Message-ID: <CC2F7731.4643E%keir@xen.org> (raw)
In-Reply-To: <5009B505.8030900@theshore.net>

On 20/07/2012 20:44, "Christopher S. Aker" <caker@theshore.net> wrote:

> On 7/20/12 3:31 PM, Keir Fraser wrote:
>> Somehow dom0 disabled the serial-line interrupt during boot. Possibly it
>> appeared as a PnP device in some BIOS table and dom0 decided to disable it
>> because it doesn't think it is being used. Xen would usually stop this
>> happening via programming of the IO-APIC/XT-PIC but perhaps there is some
>> other method of disabling it on this mainboard, which Xen doesn't catch.
> 
> Hmm -- except dom0 hasn't even booted yet at the time the serial stops
> working.  Xen is 30-60 seconds away from booting dom0 given the RAM
> scrub still has to happen.

Then it is Xen doing something to kill the serial interrupt. ;-) I haven't
seen anything like this reported before. Not sure what to suggest really...
Gather debug output from interrupt-related debug keys (via the xl debug-keys
interface) I suppose. I think that would be 'i' and 'z' keys. That plus Xen
and dom0 boot logs... something might become apparent.

 -- Keir

> -Chris

  reply	other threads:[~2012-07-20 19:59 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-12 19:34 Xen 4 occasionally hangs during boot Christopher S. Aker
2011-10-13  7:04 ` Jan Beulich
2011-10-13 10:46 ` Tim Deegan
2012-07-20 17:48   ` Xen 4 serial " Christopher S. Aker
2012-07-20 17:49     ` Andrew Cooper
2012-07-20 17:58       ` Christopher S. Aker
2012-07-20 18:05         ` Andrew Cooper
2012-07-20 19:10           ` Christopher S. Aker
2012-07-20 19:25             ` Andrew Cooper
2012-07-20 19:31             ` Keir Fraser
2012-07-20 19:44               ` Christopher S. Aker
2012-07-20 19:59                 ` Keir Fraser [this message]
2012-07-23 14:13                   ` Konrad Rzeszutek Wilk
2012-07-23 15:26                     ` Keir Fraser
2012-07-23 20:53                   ` Christopher S. Aker
2012-07-23 22:03                     ` Malcolm Crossley
2012-07-23 22:45                     ` Malcolm Crossley
2012-07-24  9:40                     ` Andrew Cooper
2012-07-24 10:32                     ` Jan Beulich
2012-07-26 13:50                       ` Konrad Rzeszutek Wilk
2012-07-26 14:10                         ` Jan Beulich
2012-07-26 14:36                           ` Konrad Rzeszutek Wilk
2012-07-24 10:46                     ` Jan Beulich

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