On Tue, 24 Jul 2018 12:30:35 +0100 Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> wrote: > Hi Baolu, > > On 24/07/18 03:22, Lu Baolu wrote: > > Hi, > > > > On 07/23/2018 12:44 PM, Liu, Yi L wrote: > >>> From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx] > >>> Sent: Sunday, July 22, 2018 2:09 PM > >>> > >>> With the Intel IOMMU supporting PASID granularity isolation and protection, a > >>> mediated device could be isolated and protected by an IOMMU unit. We need to > >>> allocate a new group instead of a PCI group. > >> Existing vfio mdev framework also allocates an iommu group for mediate device. > >> > >> mdev_probe() > >> |_ mdev_attach_iommu() > >> |_ iommu_group_alloc() > > > > When external components ask iommu to allocate a group for a device, > > it will call pci_device_group in Intel IOMMU driver's @device_group > > callback. In another word, current Intel IOMMU driver doesn't aware > > the mediated device and treat all devices as PCI ones. This patch > > extends the @device_group call back to make it aware of a mediated > > device. > > I agree that allocating two groups for an mdev seems strange, and in my > opinion we shouldn't export the notion of mdev to IOMMU drivers. Yep, I was just thinking the same thing. This is too highly integrated into VT-d and too narrowly focused on PASID being the only way that an mdev could make use of the IOMMU. Thanks, Alex
