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Date: Tue, 04 May 2010 10:35:16 +0200
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] Qemu-KVM 0.12.3 and Multipath -> Assertion
References: <4BDF3F94.1080608@dlh.net>
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To: Peter Lieven <pl@dlh.net>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org

Am 03.05.2010 23:26, schrieb Peter Lieven:
> Hi Qemu/KVM Devel Team,
> 
> i'm using qemu-kvm 0.12.3 with latest Kernel 2.6.33.3.
> As backend we use open-iSCSI with dm-multipath.
> 
> Multipath is configured to queue i/o if no path is available.
> 
> If we create a failure on all paths, qemu starts to consume 100%
> CPU due to i/o waits which is ok so far.
> 
> 1 odd thing: The Monitor Interface is not responding any more ...
> 
> What es a really blocker is that KVM crashes with:
> kvm: /usr/src/qemu-kvm-0.12.3/hw/ide/internal.h:507: bmdma_active_if: 
> Assertion `bmdma->unit != (uint8_t)-1' failed.
> 
> after the multipath has reestablisched at least one path.

Can you get a stack backtrace with gdb?

> Any ideas? I remember this was working with earlier kernel/kvm/qemu 
> versions.

If it works in the same setup with an older qemu version, bisecting
might help.

Kevin