Re: [Qemu-devel] [PATCH v2 1/1] virtio: serial: expose a 'guest_writable' callback for users

[Peter Maydell]

On 10 October 2014 12:19, Amit Shah <address@hidden> wrote:
> On (Thu) 09 Oct 2014 [14:04:53], Peter Maydell wrote:
>> What I would like to see in this patch is a comment giving
>> much clearer definition of the semantics of the guest_writable
>> call: for instance, is it always called when the guest is
>> writable, or is it only guaranteed to be called if the
>> QEMU backend has previously tried to do virtio_serial_write
>> and got back a return code indicating an incomplete write?
>
> Right now it's called always; if it's necessary to only call after an
> incomplete / failed write, we just need to implement that (and also
> add that state to the migration data).
>
> I have no preference; just depends on the users of the API.

Called-always makes sense; I'd just like to see the semantics
documented so you don't have to read the whole implementation
of virtio to figure out what they are :-)

-- PMM