Re: [Qemu-devel] [PATCH] spapr-vscsi: Adding VSCSI capabilities

[Paolo Bonzini]

Il 26/08/2013 11:06, Nikunj A Dadhania ha scritto:
>>> +        fprintf(stderr, "vscsi_send_capabilities: size out of bound !\n");
>>> +        goto error_out;
>>> +    }
>>
>> I am not 100% familiar with the protocol, could it be that we should
>> just read sizeof(cap) instead of erroring out or is there no way it
>> can be correct and have a len too long ?
> 
> If the length is incorrect, can we trust whether cap is correct or is of
> the type we are expecting?

We shouldn't care, it'd be a guest bug.

If the guest is asking for say 1024 bytes, we do not have to fill all of
them.  It is in principle possible that a subsequent revision of vscsi
will make the struct larger; perhaps a bit in the first part of the
struct will tell the guest if the second part has been filled.

Unless the spec explicitly say the opposite, I would just zero the bytes
between sizeof(cap) and len.

Paolo