2012/7/25 Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>:
> On Wed, Jul 25, 2012 at 10:44:14AM +0200, Paolo Bonzini wrote:
>> Il 25/07/2012 10:29, Wang Sen ha scritto:
>> > When using the commands below to write some data to a virtio-scsi LUN of 
>> > the
>> > QEMU guest(32-bit) with 1G physical memory(qemu -m 1024), the qemu will 
>> > crash.
>> >
>> >     # sudo mkfs.ext4 /dev/sdb  (/dev/sdb is the virtio-scsi LUN.)
>> >     # sudo mount /dev/sdb /mnt
>> >     # dd if=/dev/zero of=/mnt/file bs=1M count=1024
>> >
>> > In current implementation, sg_set_buf is called to add buffers to sg list 
>> > which
>> > is put into the virtqueue eventually. But there are some HighMem pages in
>> > table->sgl can not get virtual address by sg_virt. So, sg_virt(sg_elem) may
>> > return NULL value. This will cause QEMU exit when virtqueue_map_sg is 
>> > called
>> > in QEMU because an invalid GPA is passed by virtqueue.
>>
>> Heh, I was compiling (almost) the same patch as we speak. :)
>>
>> I've never seen QEMU crash; the VM would more likely just fail to boot
>> with a panic.  But it's the same bug anyway.
>
> It's not a segfault "crash", I think it hits an abort(3) in QEMU's
> virtio code when trying to map an invalid guest physical address.

How the guest boot fail? I never met this case.

>
> Stefan
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
------------------------------------------
Wang Sen
Addr: XUPT,Xi'an,Shaanxi,China
Email: kelvin.x...@gmail.com
------------------------------------------
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to