Re: [PATCH v2 6/8] iommu/vt-d: Implement set_dev_pasid domain op

[Baolu Lu]

On 3/28/23 11:40 PM, Jacob Pan wrote:
> Hi Kevin,
>
> On Tue, 28 Mar 2023 07:47:45 +0000, "Tian, Kevin" <kevin.tian@xxxxxxxxx>
> wrote:
>
> > > From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> > > Sent: Tuesday, March 28, 2023 7:22 AM
> > >
> > > Devices that use ENQCMDS to submit work on buffers mapped by DMA API
> > > must attach a PASID to the default domain of the device. In preparation
> > > for this use case, this patch implements set_dev_pasid() for the
> > > default_domain_ops. Besides PASID attachment, device will also be
> > > attached to the domain as the result of this call if the device has not
> > > been attached before.
> > >    
> >
> > I didn't get the last point. PASID attach should only have the scope
> > for the pasid. RID of the device might be attached to another domain
> > which shouldn't be changed by this call.
> I meant if the RID context has not been set up before attaching this PASID,
> this call will also set up the context, PASID dir etc. In the end, we
> eliminated ordering requirement of attaching device, RID_PASID first, then
> other PASIDs.

This occurs in default domain deferred attaching case.

> How about:
> "If the device context has not been set up prior to this call, this will
> set up the device context in addition to PASID attachment."

Best regards,
baolu