Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

[Baolu Lu]

On 4/4/23 5:48 AM, Jacob Pan wrote:
> On Sat, 1 Apr 2023 21:48:36 +0800, Baolu Lu<baolu.lu@xxxxxxxxxxxxxxx>
> wrote:
>
> > On 2023/4/1 7:11, Jacob Pan wrote:
> > > 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.
> > >
> > > 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.
> > >
> > > Signed-off-by: Jacob Pan<jacob.jun.pan@xxxxxxxxxxxxxxx>
> > > ---
> > >    drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
> > >    1 file changed, 21 insertions(+)
> > >
> > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > > index 52b9d0d3a02c..1ad9c5a4bd8f 100644
> > > --- a/drivers/iommu/intel/iommu.c
> > > +++ b/drivers/iommu/intel/iommu.c
> > > @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct
> > > device *dev, ioasid_t pasid) domain_detach_iommu(dmar_domain,
> > > info->iommu); }
> > >    
> > > +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
> > > +					   struct device *dev,
> > > ioasid_t pasid) +{
> > > +	struct device_domain_info *info = dev_iommu_priv_get(dev);
> > > +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > > +	struct intel_iommu *iommu = info->iommu;
> > > +	int ret;
> > > +
> > > +	if (!pasid_supported(iommu))
> > > +		return -ENODEV;
> > As the domain ID will be set to the pasid entry, need to get a refcount
> > of the domain ID. Call domain_attach_iommu() here, and release it after
> > the pasid entry is torn down.
> dmar_domain_attach_device_pasid() below will call domain_attach_iommu() and
> release in intel_iommu_remove_dev_pasid(). The previous patch has
> consolidated the code path with device attachment.
> would it be sufficient?

It's fine. Sorry, I overlooked this.

Best regards,
baolu