Re: [Qemu-devel] scsi: lsi problems since "unit attention on reset"

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-09-26 09:50, Paolo Bonzini wrote:
> On 09/26/2011 09:27 AM, Jan Kiszka wrote:
>> Hi Paolo,
>>
>> I'm facing problems over latest qemu with our special guest OS that is
>> using the LSI controller. It hangs during boot now. This can be resolved
>> by reverting commit c7b488721d (scsi: report unit attention on reset).
>>
>> I cannot exclude a bug in the guest driver at this point, but maybe you
>> also have some idea what could go wrong in the SCSI stack or the LSI
>> emulation. Any suggestions where to look at would be welcome.
> 
> It works for me under Linux, so I suspect it is a bug in the guest OS or 
> the BIOS, which should send TEST UNIT READY before trying to communicate 
> to the HBA.  You can use tracing to detect that, it probably sends 
> something like READ CAPACITY and fails because it does not expect that 
> command to fail.

I'm just getting these scsi events, then the guest stops:

scsi_req_parsed target 0 lun 0 tag 0 command 0 dir 0 length 0
scsi_req_parsed_lba target 0 lun 0 tag 0 command 0 lba 0
scsi_req_alloc target 0 lun 0 tag 0
scsi_test_unit_ready target 0 lun 0 tag 0
scsi_req_build_sense target 0 lun 0 tag 0 key 0x6 asc 0x29 ascq 00
scsi_req_dequeue target 0 lun 0 tag 0

> 
> That said, since there are 3 out of 3 BIOSes that couldn't cope with 
> that change---Linux and Windows work of course---it makes sense to 
> revert it even though the patch by itself is correct.  If you send it 
> out, I'll gladly add my Acked-by.

We are currently checking the driver situation internally. But if you
say you want it reverted in any case, I'll send a patch.

Jan

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