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From: "Richard W.M. Jones" <rjones@redhat.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: "kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>
Subject: Re: kvm [2087]: load/store instruction decoding not implemented
Date: Tue, 24 Feb 2015 13:45:33 +0000	[thread overview]
Message-ID: <20150224134533.GM11603@redhat.com> (raw)
In-Reply-To: <54EC78D1.3030703@arm.com>

On Tue, Feb 24, 2015 at 01:12:49PM +0000, Marc Zyngier wrote:
> Here's my theory: userspace is accessing something it should never
> access (outside of RAM, basically), and doing so via a kernel interface.
> 
> Is this process accessing /dev/mem by any chance? dmidecode anyone?

Not as far as I know.  The userspace process is inserting modules.

Here is the userspace function which is most likely to be running:

https://github.com/libguestfs/supermin/blob/master/src/init.c#L292

Unfortunately because of lack of a full stack trace, I can't be sure
exactly what system call is failing, but I'll probably add more debug
to the userspace program later.

BTW this worked fine in 3.19.  It's started failing in 3.20/4.0.  It
also works fine on x86.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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software inside the virtual machine.  Supports Linux and Windows.
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  reply	other threads:[~2015-02-24 13:40 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-24 11:59 kvm [2087]: load/store instruction decoding not implemented Richard W.M. Jones
2015-02-24 12:15 ` Peter Maydell
2015-02-24 12:29   ` Richard W.M. Jones
2015-02-24 12:47     ` Christoffer Dall
2015-02-24 13:12       ` Marc Zyngier
2015-02-24 13:45         ` Richard W.M. Jones [this message]
2015-02-24 14:10           ` Marc Zyngier
2015-02-24 14:36             ` Richard W.M. Jones
2015-02-24 14:42               ` Marc Zyngier
2015-02-24 14:43                 ` Richard W.M. Jones
2015-02-24 15:03                   ` Marc Zyngier
2015-02-24 15:09                 ` Richard W.M. Jones
2015-02-24 15:20                   ` Marc Zyngier
2015-02-24 16:37                   ` Marc Zyngier
2015-02-24 14:25       ` Richard W.M. Jones
2015-02-24 14:55         ` Christoffer Dall
2015-02-24 15:06           ` Peter Maydell
2015-02-24 15:22           ` Richard W.M. Jones
2015-02-24 12:57     ` Peter Maydell
2015-02-24 12:16 ` Christoffer Dall
2015-02-24 12:27   ` Richard W.M. Jones

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