From: Joao Martins Date: Tue, 24 Oct 2023 13:50:56 +0000 (+0100) Subject: iommufd: Add a flag to enforce dirty tracking on attach X-Git-Tag: v6.7-rc1~121^2~37 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5f9bdbf4c65860cc8b9c544d92bfd76fbea8d9c5;p=thirdparty%2Fkernel%2Flinux.git iommufd: Add a flag to enforce dirty tracking on attach Throughout IOMMU domain lifetime that wants to use dirty tracking, some guarantees are needed such that any device attached to the iommu_domain supports dirty tracking. The idea is to handle a case where IOMMU in the system are assymetric feature-wise and thus the capability may not be supported for all devices. The enforcement is done by adding a flag into HWPT_ALLOC namely: IOMMU_HWPT_ALLOC_DIRTY_TRACKING .. Passed in HWPT_ALLOC ioctl() flags. The enforcement is done by creating a iommu_domain via domain_alloc_user() and validating the requested flags with what the device IOMMU supports (and failing accordingly) advertised). Advertising the new IOMMU domain feature flag requires that the individual iommu driver capability is supported when a future device attachment happens. Link: https://lore.kernel.org/r/20231024135109.73787-6-joao.m.martins@oracle.com Signed-off-by: Joao Martins Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 8b3d2875d642d..dd50ca9e2c096 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -157,7 +157,9 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) struct iommufd_ioas *ioas; int rc; - if ((cmd->flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT)) || cmd->__reserved) + if ((cmd->flags & ~(IOMMU_HWPT_ALLOC_NEST_PARENT | + IOMMU_HWPT_ALLOC_DIRTY_TRACKING)) || + cmd->__reserved) return -EOPNOTSUPP; idev = iommufd_get_device(ucmd, cmd->dev_id); diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index be7a95042677b..c76248410120a 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -351,9 +351,12 @@ struct iommu_vfio_ioas { * enum iommufd_hwpt_alloc_flags - Flags for HWPT allocation * @IOMMU_HWPT_ALLOC_NEST_PARENT: If set, allocate a HWPT that can serve as * the parent HWPT in a nesting configuration. + * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is + * enforced on device attachment */ enum iommufd_hwpt_alloc_flags { IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0, + IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1, }; /**