Re: [RFC PATCH 10/24] vdpa: introduce config operations for associating ASID to a virtqueue group

[Eli Cohen]

On Fri, Oct 09, 2020 at 11:56:45AM +0800, Jason Wang wrote:
> 
> On 2020/10/1 下午9:29, Eli Cohen wrote:
> > On Thu, Sep 24, 2020 at 11:21:11AM +0800, Jason Wang wrote:
> > > This patch introduces a new bus operation to allow the vDPA bus driver
> > > to associate an ASID to a virtqueue group.
> > > 
> > So in case of virtio_net, I would expect that all the data virtqueues
> > will be associated with the same address space identifier.
> 
> 
> Right.
> 
> I will add the codes to do this in the next version. It should be more
> explicit than have this assumption by default.
> 
> 
> > Moreover,
> > this assignment should be provided before the set_map call that provides
> > the iotlb for the address space, correct?
> 
> 
> I think it's better not have this limitation, note that set_map() now takes
> a asid argument.
> 
> So for hardware if the associated as is changed, the driver needs to program
> the hardware to switch to the new mapping.
> 
> Does this work for mlx5?
> 

So in theory we can have several asid's (for different virtqueues), each
one should be followed by a specific set_map call. If this is so, how do
I know if I met all the conditions run my driver? Maybe we need another
callback to let the driver know it should not expect more set_maps().