On 5/8/24 8:25 AM, Jason Gunthorpe wrote:
On Tue, Apr 30, 2024 at 10:57:08PM +0800, Lu Baolu wrote:/** @@ -412,6 +415,9 @@ enum iommu_hwpt_data_type { * @data_type: One of enum iommu_hwpt_data_type * @data_len: Length of the type specific data * @data_uptr: User pointer to the type specific data + * @fault_id: The ID of IOMMUFD_FAULT object. Valid only if flags field of + * IOMMU_HWPT_FAULT_ID_VALID is set. + * @__reserved2: Padding to 64-bit alignment. Must be 0. * * Explicitly allocate a hardware page table object. This is the same object * type that is returned by iommufd_device_attach() and represents the @@ -442,6 +448,8 @@ struct iommu_hwpt_alloc { __u32 data_type; __u32 data_len; __aligned_u64 data_uptr; + __u32 fault_id; + __u32 __reserved2; }; #define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)[..]@@ -359,7 +359,7 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_GET_HW_INFO, iommufd_get_hw_info, struct iommu_hw_info, __reserved), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, - __reserved), + __reserved2),This is now how the back compat mechanism works. The value here is the absolute minimum size, it should never increase. The first __reserved is always the right value. If you change it then old userspace that doesn't include the fault_id will stop working.
Yeah! I will remove this change. Best regards, baolu
