Re: [PATCH v6 1/5] iommu: Return -EMEDIUMTYPE for incompatible domain and device/group
From: Joerg Roedel <joro@8bytes.org>
Date: 2022-09-07 12:51:21
Also in:
asahi, kvm, linux-arm-kernel, linux-arm-msm, linux-iommu, linux-s390, linux-tegra, lkml
On Mon, Aug 15, 2022 at 11:14:33AM -0700, Nicolin Chen wrote:
Provide a dedicated errno from the IOMMU driver during attach that the reason attached failed is because of domain incompatability. EMEDIUMTYPE is chosen because it is never used within the iommu subsystem today and evokes a sense that the 'medium' aka the domain is incompatible.
I am not a fan of re-using EMEDIUMTYPE or any other special value. What is needed here in EINVAL, but with a way to tell the caller which of the function parameters is actually invalid. For that I prefer adding an additional pointer parameter to the attach functions in which the reason for the failure can be communicated up the chain. For the top-level iommu_attach_device() function I am okay with having a special version which has this additional paremter. Regards, Joerg _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization