This provides a way for userspace to probe supported stage-1 page table types on hardware IOMMU. This is helpful when the user-managed page table is used by hardware IOMMU. e.g. nested translation.
This commit reports the supported types for IOMMU_DEVICE_DATA_INTEL_VTD.
Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommufd/device.c | 7 +++++++ drivers/iommu/iommufd/main.c | 2 +- include/uapi/linux/iommufd.h | 7 +++++++ 3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index c19e2f54a44f..826441c6005d 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -224,6 +224,13 @@ int iommufd_device_get_info(struct iommufd_ucmd *ucmd) cmd->out_device_type = ops->driver_type; cmd->data_len = data_len;
+ if (ops->driver_type != IOMMU_DEVICE_DATA_SELFTEST) + cmd->out_pgtbl_type_bitmap = iommufd_supported_pgtbl_types[ops->driver_type]; +#ifdef CONFIG_IOMMUFD_TEST + else + cmd->out_pgtbl_type_bitmap = 0; +#endif + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
out_free_data: diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 6e2d8805daf3..d8bac1303b33 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -290,7 +290,7 @@ struct iommufd_ioctl_op { static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), IOCTL_OP(IOMMU_DEVICE_GET_INFO, iommufd_device_get_info, struct iommu_device_info, - __reserved), + out_pgtbl_type_bitmap), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, __reserved), IOCTL_OP(IOMMU_HWPT_INVALIDATE, iommufd_hwpt_invalidate, diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index cb6a9ee215f4..2c7533d843bc 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -396,6 +396,8 @@ enum iommu_pgtbl_data_type { * @out_device_type: Output the underlying iommu hardware type, it is * one of enum iommu_device_data_type. * @__reserved: Must be 0 + * @out_pgtbl_type_bitmap: Output the supported page table type. Each + * bit is defined in enum iommu_pgtbl_data_type. * * Query the hardware iommu capability for given device which has been * bound to iommufd. @data_len is set to be the size of the buffer to @@ -408,6 +410,10 @@ enum iommu_pgtbl_data_type { * * The @out_device_type will be filled if the ioctl succeeds. It would * be used to decode the data filled in the buffer pointed by @data_ptr. + * + * @out_pgtbl_type_bitmap tells the userspace the supported page tables. + * This differs per @out_device_type. Userspace should check it before + * allocating hw_pagetable in userspace. */ struct iommu_device_info { __u32 size; @@ -417,6 +423,7 @@ struct iommu_device_info { __aligned_u64 data_ptr; __u32 out_device_type; __u32 __reserved; + __aligned_u64 out_pgtbl_type_bitmap; }; #define IOMMU_DEVICE_GET_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DEVICE_GET_INFO)