Re: [PATCH v4 2/8] iommu/vt-d: Add multiple domains per device query

[Lu Baolu]

Hi,

On 11/23/18 6:49 PM, Auger Eric wrote:
> Hi,
>
> On 11/5/18 8:34 AM, Lu Baolu wrote:
> > Add the response to IOMMU_DEV_ATTR_AUXD_CAPABILITY capability query
> > through iommu_get_dev_attr().
>
> commit title: Advertise auxiliary domain capability?

Yes. I should make it consistent. Thanks.

> > Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
> > Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> > Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> > ---
> >   drivers/iommu/intel-iommu.c | 38 +++++++++++++++++++++++++++++++++++++
> >   1 file changed, 38 insertions(+)
> >
> > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> > index 5e149d26ea9b..298f7a3fafe8 100644
> > --- a/drivers/iommu/intel-iommu.c
> > +++ b/drivers/iommu/intel-iommu.c
> > @@ -5167,6 +5167,24 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
> >   	return phys;
> >   }
> >   
> > +static inline bool scalable_mode_support(void)
> > +{
> > +	struct dmar_drhd_unit *drhd;
> > +	struct intel_iommu *iommu;
> > +	bool ret = true;
> > +
> > +	rcu_read_lock();
> > +	for_each_active_iommu(iommu, drhd) {
> > +		if (!sm_supported(iommu)) {
> > +			ret = false;
> > +			break;
> > +		}
> > +	}
> > +	rcu_read_unlock();
> > +
> > +	return ret;
> > +}
> > +
> >   static bool intel_iommu_capable(enum iommu_cap cap)
> >   {
> >   	if (cap == IOMMU_CAP_CACHE_COHERENCY)
> > @@ -5331,6 +5349,25 @@ struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
> >   }
> >   #endif /* CONFIG_INTEL_IOMMU_SVM */
> >   
> > +static int intel_iommu_get_dev_attr(struct device *dev,
> > +				    enum iommu_dev_attr attr, void *data)
> > +{
> > +	int ret = 0;
> > +	bool *auxd_capable;
> nit: could be local to the case as other cases may use other datatypes.

I have thought about this. Making it local to the case needs extra "{}".
That's the reason I put it here. We can change it later when we need
other datatypes.

> > +
> > +	switch (attr) {
> > +	case IOMMU_DEV_ATTR_AUXD_CAPABILITY:
> > +		auxd_capable = data;
> > +		*auxd_capable = scalable_mode_support();
> > +		break;
> > +	default:
> > +		ret = -EINVAL;
> > +		break;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >   const struct iommu_ops intel_iommu_ops = {
> >   	.capable		= intel_iommu_capable,
> >   	.domain_alloc		= intel_iommu_domain_alloc,
> > @@ -5345,6 +5382,7 @@ const struct iommu_ops intel_iommu_ops = {
> >   	.get_resv_regions	= intel_iommu_get_resv_regions,
> >   	.put_resv_regions	= intel_iommu_put_resv_regions,
> >   	.device_group		= pci_device_group,
> > +	.get_dev_attr		= intel_iommu_get_dev_attr,
> >   	.pgsize_bitmap		= INTEL_IOMMU_PGSIZES,
> >   };
> >   
> Thanks
>
> Eric

Best regards,
Lu Baolu