Re: [Qemu-devel] [patch] fix scsi-generic

[adq]

On 8 August 2010 23:13, adq <address@hidden> wrote:
> Hi, more information on the command that is (now) killing my
> qemu+scsi-generic in case someone else can help... Its our old friend
> the READ DVD STRUCTURE command:
>
> CMD: 00 ad
> CMD: 01 00
> CMD: 02 00
> CMD: 03 00
> CMD: 04 00
> CMD: 05 00
> CMD: 06 00
> CMD: 07 01
> CMD: 08 00
> CMD: 09 08
> CMD: 0a 00
> CMD: 0b 00
>
> What seems to happen is that it is sent to the sg device, but
> lsi_command_complete() function is never called for it. Instead, I get
> a message 0xc, or BUS DEVICE RESET. Since that isn't actually
> implemented, everything seems to screw up after that point.
>

Figured out what the problem is - READ DVD STRUCTURE has its xfer
length in an unexpected place, so hw/scsi-bus.c retrieves completely
the wrong value for the transfer length. Attached nasty hacky (!)
patch fixes it as a proof of concept, will see what I can do to clean
it up later. I'd probably want it to warn if it sees SCSI commands it
doesn't know how to explicitly handle to aid debugging this sort of
thing in future.

hack.patch
Description: Text Data