Re: [Qemu-devel] [PATCH] Fix ATAPI GET_CONFIGURATION function

[Carlo Marcelo Arenas Belon]

On Sat, May 24, 2008 at 12:31:01PM +0200, Alexander Graf wrote:
> Is there anything particularly wrong with this patch?

no, but the SPEC (I used MMC6 r01) says :

6.5.1.4 Allocation Length

The Allocation Length field specifies the maximum length in bytes of the Get
Configuration response data.  An Allocation Length field of zero indicates
that no data shall be transferred.  This condition shall not be considered an
error.

this is only implicitly supported by truncating the response using max_len
for the ide_atapi_cmd_reply with your patch and so the work of generating the
response is still happening regardless.

> Does it break any guest OSs I am not aware of?

the original implementation (*) broke [Open]Solaris by overflowing the buffer
that was used in the calls to detect the CDROM/DVDROM (using a 8 byte buffer)

Carlo

(*) http://svn.savannah.gnu.org/viewvc/trunk/hw/ide.c?root=qemu&r1=3147&r2=3161