On 10/29/13 06:29, Rusty Russell wrote:
> Laszlo Ersek <> writes:
>> So:
>> - What's the motivation for the "acquire/release" semantics of QueuePFN?
>> - Am I right that device reset should force a QueuePFN reset?
>
> Hi Laszlo,
>
> The latching behaviour is basically a debugging helper, but
> clearly device reset should set it to 0.
>
> For the v2 layout proposed for the spec, we have this:
Is there a public git repo for v2?
>
> +* 0x03c | RW | QueueReady
> + Virtual queue ready bit.
> + Writing one (0x1) to this register notifies the Host that the
> + virtual queue is ready to be used. Reading from this register
> + returns the last value written to it. Both read and write
> + accesses apply to the queue selected by writing to QueueSel.
> + When the Guest wants to stop using the queue it must write
> + zero (0x0) to this register and read the value back to
> + ensure synchronisation.
>
> I suggest we add:
>
> This register will be 0 on reset.
... "for all valid QueueSel values"?
Thanks!
Laszlo
