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

[Auger Eric <eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

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?
> 
> Cc: Ashok Raj <ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Cc: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Cc: Kevin Tian <kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Liu Yi L <yi.l.liu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
>  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.
> +
> +	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