On 18/08/17 17:04, Bjorn Helgaas wrote: > [+cc Robin] > > This series looks fine to me as far as PCI is concerned, and I'd be > happy to take it via my tree given an ack from David for this IOMMU > piece. Alternatively, you can add my > > Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > to the other patches if you want to take it via another tree. > > Robin raised a question about basically this same patch the first time > around. Not sure whether there's still an objection there. Oh, I don't actually mind the patch as-is - implementing proper IOMMU group support for VMD almost certainly should be the longer-term goal, but for all I know that may be non-trivial so in the meantime a quick and simple way to make things safe is good, however heavy-handed. Robin. > On Thu, Aug 17, 2017 at 12:10:14PM -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> >> --- >> drivers/iommu/intel-iommu.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index 687f18f..94353a6e 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -901,6 +901,11 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf >> struct pci_dev *pf_pdev; >> >> pdev = to_pci_dev(dev); >> + >> + /* VMD child devices currently cannot be handled individually */ >> + if (is_vmd(pdev->bus)) >> + return NULL; >> + >> /* VFs aren't listed in scope tables; we need to look up >> * the PF instead to find the IOMMU. */ >> pf_pdev = pci_physfn(pdev); >> -- >> 2.9.4 >>
