Tian, Kevin
2022-Sep-21 08:14 UTC
[PATCH v3 5/6] iommu: Use EINVAL for incompatible device/domain in ->attach_dev
> From: Jason Gunthorpe <jgg at nvidia.com> > Sent: Wednesday, September 21, 2022 2:07 AM > > On Tue, Sep 20, 2022 at 06:38:18AM +0000, Tian, Kevin wrote: > > > Above lacks of a conversion in intel-iommu: > > > > intel_iommu_attach_device() > > if (domain->type == IOMMU_DOMAIN_UNMANAGED && > > device_is_rmrr_locked(dev)) { > > dev_warn(dev, "Device is ineligible for IOMMU domain > attach due to platform RMRR requirement. Contact your platform > vendor.\n"); > > return -EPERM; > > } > > > > since it's based on the domain type, picking a different domain > > may work in theory though it won't apply to vfio which always > > creates unmanaged type. > > IMHO this test shouldn't even be here, that is why it is so > strange.. > > VFIO should be checking if somehow the device doesn't support > unmanaged domains at all. We already have several drivers that can't > support full featured unamanged domains that vfio needs, this is just > another case of that. > > But it isn't urgent to fix, I would just ignore this branch for this > series. >OK, then let's leave it as is. Anyway this is a rare path. In reality most RMRR devices are gpu/usb which are already exempted from the above check.