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From: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
To: "Dong, Eddie" <eddie.dong-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: kvm-devel <kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Subject: Re: guest reboot error
Date: Thu, 27 Sep 2007 12:48:05 +0200	[thread overview]
Message-ID: <46FB8A65.6000504@qumranet.com> (raw)
In-Reply-To: <10EA09EFD8728347A513008B6B0DA77A022AE445-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>

Dong, Eddie wrote:
> kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org wrote:
>   
>> I try to implement the guest reboot support, but I found there is an
>> stranger #PF VM Exit in guest real mode cs:ip=f000:10000 which is
>> problemtic and current shadow won;t handle. I then try to
>> use -no-kvm-irqchip and get same error.
>>
>> Can somebody give me more information if you ever successfully
>> run it before.
>> thx,eddie
>>
>>     
> correction:  It is GP fault, not #PF fault.
>
>   

Looks like the bios code was overwritten. If the reboot vector at
f000:fff0 was zeroed out, kvm would just execute a bunch of two-byte
instructions eventually leading to rip = 10000 which is illegal for
vm8086 mode.


Can you add code to kvmctl.c to dump the contents of that memory region
at the time of failure?


-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.


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  parent reply	other threads:[~2007-09-27 10:48 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-27  9:58 guest reboot error Dong, Eddie
     [not found] ` <10EA09EFD8728347A513008B6B0DA77A022AE441-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-09-27 10:09   ` Dong, Eddie
     [not found]     ` <10EA09EFD8728347A513008B6B0DA77A022AE445-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-09-27 10:48       ` Avi Kivity [this message]
     [not found]         ` <46FB8A65.6000504-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-09-28  2:27           ` Dong, Eddie
     [not found]             ` <10EA09EFD8728347A513008B6B0DA77A022AE67A-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-09-28  8:56               ` Dong, Eddie
     [not found]                 ` <10EA09EFD8728347A513008B6B0DA77A022AE9B4-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-09-28 14:38                   ` Avi Kivity
     [not found]                     ` <46FD11C8.8040701-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-09-29 10:29                       ` Dong, Eddie
     [not found]                         ` <10EA09EFD8728347A513008B6B0DA77A022AEB9A-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-09-30 10:51                           ` Avi Kivity
2007-09-28 14:44               ` Avi Kivity

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