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Date: Mon, 8 Apr 2013 17:53:27 +0200
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20130408155327.GD22660@stefanha-thinkpad.redhat.com>
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Subject: Re: [Qemu-devel] virtio-scsi WRITE_VERIFY crash
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To: Venkatesh Srinivas <venkateshs@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, Asias He <asias@redhat.com>, qemu-devel@nongnu.org

On Fri, Apr 05, 2013 at 11:30:00AM -0700, Venkatesh Srinivas wrote:
> When a Linux guest does a simple 'sg_verify /dev/<scsi disk on a
> virtio-scsi HBA>', qemu (-master from git) crashes, tripping an
> assertion in scsi-disk.c:scsi_dma_complete(), that the completing DMA
> command has no IOCB.
> 
> The callpath is:
> scsi_dma_complete
> dma_complete
> dma_bdrv_cb
> dma_bdrv_io
> dma_bdrv_read
> scsi_do_read
> bdrv_co_em_bh
> aio_bh_poll
> aio_poll.
> 
> At the assertion, we have a zero-element iovector and the request has
> a status of -1.

CCing Paolo Bonzini and Asias He.  See the ./MAINTAINERS file to find
people that can help with specific QEMU subsystems.

It would be nice to include a full gdb backtrace when possible since
that may include extra information like that value of arguments in the
call stack.

Stefan