This provides a way for userspace to probe the supported hwpt data types by kernel. Currently, kernel only supports IOMMU_HWPT_TYPE_DEFAULT, new types would be added per vendor drivers' extension.
Userspace that wants to allocate hw_pagetable with user data should check this. While for the allocation without user data, no need for it. It is supported by default.
Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommufd/device.c | 1 + drivers/iommu/iommufd/hw_pagetable.c | 18 +++++++++++++++--- drivers/iommu/iommufd/iommufd_private.h | 2 ++ drivers/iommu/iommufd/main.c | 2 +- include/uapi/linux/iommufd.h | 8 ++++++++ 5 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 19cd6df46c6a..0328071dcac1 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -322,6 +322,7 @@ int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd)
cmd->out_data_type = ops->driver_type; cmd->data_len = length; + cmd->out_hwpt_type_bitmap = iommufd_hwpt_type_bitmaps[ops->driver_type];
rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 67facca98de1..160712256c64 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -173,6 +173,14 @@ static const size_t iommufd_hwpt_alloc_data_size[] = { [IOMMU_HWPT_TYPE_DEFAULT] = 0, };
+/* + * bitmaps of supported hwpt types of by underlying iommu, indexed + * by ops->driver_type which is one of enum iommu_hw_info_type. + */ +const u64 iommufd_hwpt_type_bitmaps[] = { + [IOMMU_HW_INFO_TYPE_DEFAULT] = BIT_ULL(IOMMU_HWPT_TYPE_DEFAULT), +}; + int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) { struct iommu_hwpt_alloc *cmd = ucmd->cmd; @@ -182,7 +190,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) struct iommufd_ioas *ioas; const struct iommu_ops *ops; void *data = NULL; - u32 klen; + u32 driver_type, klen; int rc;
if (cmd->__reserved || cmd->flags) @@ -198,8 +206,12 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) goto out_put_idev; }
- /* Only support IOMMU_HWPT_TYPE_DEFAULT for now */ - if (cmd->data_type != IOMMU_HWPT_TYPE_DEFAULT) { + driver_type = ops->driver_type; + + /* data_type should be a supported type by the driver */ + if (WARN_ON(driver_type >= ARRAY_SIZE(iommufd_hwpt_type_bitmaps)) || + !((1 << cmd->data_type) & + iommufd_hwpt_type_bitmaps[driver_type])) { rc = -EINVAL; goto out_put_idev; } diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index d879264d1acf..164ccfc2e6e0 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -321,6 +321,8 @@ iommufd_get_device(struct iommufd_ucmd *ucmd, u32 id) void iommufd_device_destroy(struct iommufd_object *obj); int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd);
+extern const u64 iommufd_hwpt_type_bitmaps[]; + struct iommufd_access { struct iommufd_object obj; struct iommufd_ctx *ictx; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 2cf45f65b637..7ec3ceac01b3 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -298,7 +298,7 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, data_uptr), IOCTL_OP(IOMMU_DEVICE_GET_HW_INFO, iommufd_device_get_hw_info, - struct iommu_hw_info, __reserved), + struct iommu_hw_info, out_hwpt_type_bitmap), IOCTL_OP(IOMMU_HWPT_INVALIDATE, iommufd_hwpt_invalidate, struct iommu_hwpt_invalidate, data_uptr), IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index d0962c41f8d6..e2eff9c56ab3 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -421,6 +421,8 @@ enum iommu_hw_info_type { * @out_data_type: Output the iommu hardware info type, it is one of * enum iommu_hw_info_type. * @__reserved: Must be 0 + * @out_hwpt_type_bitmap: Output the supported page table type. Each + * bit is defined in enum iommu_hwpt_type. * * Query the hardware iommu information for given device which has been * bound to iommufd. @data_len is the size of the buffer which captures @@ -435,6 +437,11 @@ enum iommu_hw_info_type { * The @out_data_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_hwpt_type_bitmap reports the supported hwpt types. This differs + * per the @out_data_type. Userspace should check it before allocating a + * user-managed hw_pagetable with user data, unless it allocates a default + * hw_pagetable that does not need user data. + * * This is only available for the physical devices bound to iommufd as * only physical devices can have hardware IOMMU. */ @@ -446,6 +453,7 @@ struct iommu_hw_info { __aligned_u64 data_ptr; __u32 out_data_type; __u32 __reserved; + __aligned_u64 out_hwpt_type_bitmap; }; #define IOMMU_DEVICE_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DEVICE_GET_HW_INFO)