From 9dcef98dbee35b8ae784df04c041efffdd42a69c Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Thu, 12 Mar 2026 17:36:35 -0700 Subject: iommu/tegra241-cmdqv: Update uAPI to clarify HYP_OWN requirement >From hardware implementation perspective, a guest tegra241-cmdqv hardware is different than the host hardware: - Host HW is backed by a VINTF (HYP_OWN=1) - Guest HW is backed by a VINTF (HYP_OWN=0) The kernel driver has an implementation requirement of the HYP_OWN bit in the VM. So, VMM must follow that to allow the same copy of Linux to work. Add this requirement to the uAPI, which is currently missing. Fixes: 4dc0d12474f9 ("iommu/tegra241-cmdqv: Add user-space use support") Signed-off-by: Nicolin Chen Reviewed-by: Eric Auger Reviewed-by: Jason Gunthorpe Signed-off-by: Will Deacon --- include/uapi/linux/iommufd.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 1dafbc552d37..f63edbe71d54 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -1052,6 +1052,11 @@ struct iommu_fault_alloc { enum iommu_viommu_type { IOMMU_VIOMMU_TYPE_DEFAULT = 0, IOMMU_VIOMMU_TYPE_ARM_SMMUV3 = 1, + /* + * TEGRA241_CMDQV requirements (otherwise, VCMDQs will not work) + * - Kernel will allocate a VINTF (HYP_OWN=0) to back this VIOMMU. So, + * VMM must wire the HYP_OWN bit to 0 in guest VINTF_CONFIG register + */ IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV = 2, }; -- cgit v1.2.3