Hi, On 09/11/2018 12:23 AM, Jean-Philippe Brucker wrote:
On 30/08/2018 05:09, Lu Baolu wrote:+static int vfio_detach_aux_domain(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + + vfio_mdev_set_aux_domain(dev, NULL); + iommu_detach_device(domain, dev->parent);I think that's only going to work for vt-d, which doesn't use a default_domain. For other drivers, iommu.c ends up calling domain->ops->attach_dev(default_domain, dev) here, which isn't what we want.
This doesn't break any functionality. It takes effect only if iommu hardware supports finer granular translation and advertises it through the API.
That was my concern with reusing attach/detach_dev callbacks for PASID management. The attach_dev code of IOMMU drivers already has to deal with toggling between default and unmanaged domain. Dealing with more state transitions in the same path is going to be difficult.
Let's consider it from the API point of view. We have iommu_a(de)ttach_device() APIs to attach or detach a domain to/from a device. We should avoid applying a limitation of "these are only for single domain case, for multiple domains, use another API". Best regards, Lu Baolu
