Re: [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached

[Zheng Xiang]

Ping?

On 2019/2/15 11:17, Zheng Xiang wrote:
> Hi Paolo,
> 
> On 2019/2/15 2:07, Paolo Bonzini wrote:
>> On 14/02/19 13:27, Xiang Zheng wrote:
>>> There is a small window between the twice blk_is_available in
>>> scsi_disk_emulate_command which would cause crash due to the later
>>> assertion if the remote cdrom is detached in this window.
>>>
>>> So this patch replaces assertions with return to avoid qemu crash.
>>>
>>> Signed-off-by: Xiang Zheng <address@hidden>
>>> ---
>>> The qemu error log shows:
>>>
>>> qemu-system-aarch64: /home/qemu/hw/scsi/scsi-disk.c:1896: 
>>> scsi_disk_emulate_command: Assertion `blk_is_available(s->qdev.conf.blk)' 
>>> failed.
>>> 2019-02-15 04:35:18.592: shutting down, reason=crashed
>>
>> Is this with virtio-scsi-dataplane?
>>
> 
> No, the QEMU commandline about scsi is bellow:
>       -device virtio-scsi-pci,id=scsi0,bus=pci.4,addr=0x0 \
>       -drive 
> file=/mnt/zhengxiang/guestos.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0,cache=none,aio=native
>  \
>       -device 
> scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
>  \
>       -drive 
> file=/home/tmp.iso,format=raw,if=none,id=drive-scsi0-0-0-1,readonly=on,cache=none,aio=threads
>  \
>       -device 
> scsi-cd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1
> 
> This problem can be reproduced by detaching and attaching remote cdrom 
> repeatly.
> 
-- 

Thanks,
Xiang