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Date: Tue, 12 Jan 2010 20:52:51 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCHv7 3/3] virtio: add features as qdev properties
Message-ID: <20100112185251.GB3170@redhat.com>
References: <cover.1263124239.git.mst@redhat.com>
	<20100110115253.GD27013@redhat.com> <20100112180927.GA1510@lst.de>
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To: Christoph Hellwig <hch@lst.de>
Cc: qemu-devel@nongnu.org, kraxel@redhat.com

On Tue, Jan 12, 2010 at 07:09:27PM +0100, Christoph Hellwig wrote:
> This patch causes 100% reproducible boot panics in a Linux guest using
> virtio.
> 
> My qemu command line is:
> 
> /opt/qemu/bin/qemu-system-x86_64 \
>         -m 1500 \
> 	-enable-kvm \
> 	-drive file=/dev/vg00/qemu-root,if=virtio,media=disk,cache=none,aio=threads \
> 	-kernel arch/x86/boot/bzImage \
> 	-append "root=/dev/vda console=tty0 console=ttyS0,38400n8" \
> 	-nographic
> 
> and the guest dmesg is:
> 
> [    2.578083] virtio-pci 0000:00:04.0: PCI INT A -> Link[LNKD] -> GSI
> 10 (level, high) -> IRQ 10
> [    2.583111] blk_queue_max_segment_size: set to minimum 4096
> [    2.584651]  vda:
> [    2.585075] BUG: unable to handle kernel NULL pointer dereference at (null)

Um, I see this too. Debugging.

-- 
MST