On Wed, Aug 30, 2017 at 03:05:59PM -0600, Jon Derrick wrote: > VMD child devices must use the VMD endpoint's ID as the requester. > Because of this, there needs to be a way to link the parent VMD > endpoint's iommu group and associated mappings to the VMD child devices > such that attaching and detaching child devices modify the endpoint's > mappings, while preventing early detaching on a singular device removal > or unbinding. > > The reassignment of individual VMD child devices devices to VMs is > outside the scope of VMD, but may be implemented in the future. For now > it is best to prevent any such attempts. > > This patch prevents VMD child devices from returning an IOMMU, which > prevents it from exposing an iommu_group sysfs directories and allowing > subsequent binding by userspace-access drivers such as VFIO. > > Signed-off-by: Jon Derrick <jonathan.derrick@xxxxxxxxx> Applied to pci/host-vmd for v4.14, thanks! > --- > v2->3, wrapped in x86 ifdef to avoid ia64 compilation errors > > drivers/iommu/intel-iommu.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 687f18f..2800a6e 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -901,6 +901,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf > struct pci_dev *pf_pdev; > > pdev = to_pci_dev(dev); > + > +#ifdef CONFIG_X86 > + /* VMD child devices currently cannot be handled individually */ > + if (is_vmd(pdev->bus)) > + return NULL; > +#endif > + > /* VFs aren't listed in scope tables; we need to look up > * the PF instead to find the IOMMU. */ > pf_pdev = pci_physfn(pdev); > -- > 1.8.3.1 >
