Re: [Qemu-devel] Get current env within io_handler ?

[Blue Swirl]

On Mon, May 21, 2012 at 10:36 AM, Peter Maydell
<address@hidden> wrote:
> On 21 May 2012 08:21, nicolas.sauzede <address@hidden> wrote:
>> Ok, so I guess that for now, we have to live with the lack of a way to 
>> actually
>> get those io transaction properties, right ?
>> Do you think it would be feasible to allow it the future ? (for now, I've 
>> done
>> some shortcuts and ugly hardcoding in my TLM prototype to make things work, 
>> but still..)
>>
>> In fact, we encounter the same kind of issues regarding the "debug" property 
>> when doing
>> io transaction.
>
>> Do you think this feature could be useful/legitimate in upstream qemu ?
>
> I think it would be nice to have this in upstream qemu; however adding
> transaction properties to the IO interface would be quite tricky I
> suspect...

This is limited to CPU and CPU local bus devices (not generic like
PCI), so there could be an out of band mechanism to get/set the
additional data. For example store in op_helper.c could use
cpu_set_amba_properties(...) before the store and afterwards
cpu_get_amba_reply(...). An AMBA device could do the counterpart with
device_get_amba_properties() and device_set_amba_reply(). A generic
device (like NE2k) would not care about the properties or replies.

>
> -- PMM