From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: Xen 4 serial hangs during boot Date: Fri, 20 Jul 2012 20:31:52 +0100 Message-ID: References: <5009AD29.3060401@theshore.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5009AD29.3060401@theshore.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "Christopher S. Aker" , Andrew Cooper Cc: xen devel List-Id: xen-devel@lists.xenproject.org On 20/07/2012 20:10, "Christopher S. Aker" wrote: > On 7/20/12 2:05 PM, Andrew Cooper wrote: >> Alternatively, use `xl debug-keys` > > Interesting. 'xl debug-keys h' got me ~1448 bytes onto the serial > console, except it is old buffered output from exactly where it left off > during boot. 1448 bytes is about the size of 'h' output from another > working box. The same thing happened with 'm'. Xen is flushing an > equal amount of characters from the buffer as generated by debug-key > command output. > > I can continue to poke the buffer until I see output from things I've > issued, however it still refuses to respond to serial input > (control-aaa) nor can I get dom0 to echo chars. It's currently running > a * dump which has been going now for over an hour, currently on vcpu > 435628. I won't be doing that again. > > Any lightblubs going off? 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. -- Keir > -Chris > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel