From 1e6aaae93e9ddb9dc664993eb949b1da94cab3a5 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Fri, 25 Sep 2020 09:32:43 -0700 Subject: [PATCH] iommu/uapi: Add argsz for user filled data As IOMMU UAPI gets extended, user data size may increase. To support backward compatibiliy, this patch introduces a size field to each UAPI data structures. It is *always* the responsibility for the user to fill in the correct size. Padding fields are adjusted to ensure 8 byte alignment. Specific scenarios for user data handling are documented in: Documentation/userspace-api/iommu.rst As there is no current users of the API, struct version is not incremented. Signed-off-by: Liu Yi L Signed-off-by: Jacob Pan Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/1601051567-54787-3-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel --- include/uapi/linux/iommu.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h index c2b2caf9ed412..b42acc8fe007a 100644 --- a/include/uapi/linux/iommu.h +++ b/include/uapi/linux/iommu.h @@ -139,6 +139,7 @@ enum iommu_page_response_code { /** * struct iommu_page_response - Generic page response information + * @argsz: User filled size of this data * @version: API version of this structure * @flags: encodes whether the corresponding fields are valid * (IOMMU_FAULT_PAGE_RESPONSE_* values) @@ -147,6 +148,7 @@ enum iommu_page_response_code { * @code: response code from &enum iommu_page_response_code */ struct iommu_page_response { + __u32 argsz; #define IOMMU_PAGE_RESP_VERSION_1 1 __u32 version; #define IOMMU_PAGE_RESP_PASID_VALID (1 << 0) @@ -222,6 +224,7 @@ struct iommu_inv_pasid_info { /** * struct iommu_cache_invalidate_info - First level/stage invalidation * information + * @argsz: User filled size of this data * @version: API version of this structure * @cache: bitfield that allows to select which caches to invalidate * @granularity: defines the lowest granularity used for the invalidation: @@ -250,6 +253,7 @@ struct iommu_inv_pasid_info { * must support the used granularity. */ struct iommu_cache_invalidate_info { + __u32 argsz; #define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1 __u32 version; /* IOMMU paging structure cache */ @@ -259,7 +263,7 @@ struct iommu_cache_invalidate_info { #define IOMMU_CACHE_INV_TYPE_NR (3) __u8 cache; __u8 granularity; - __u8 padding[2]; + __u8 padding[6]; union { struct iommu_inv_pasid_info pasid_info; struct iommu_inv_addr_info addr_info; @@ -296,6 +300,7 @@ struct iommu_gpasid_bind_data_vtd { /** * struct iommu_gpasid_bind_data - Information about device and guest PASID binding + * @argsz: User filled size of this data * @version: Version of this data structure * @format: PASID table entry format * @flags: Additional information on guest bind request @@ -313,17 +318,18 @@ struct iommu_gpasid_bind_data_vtd { * PASID to host PASID based on this bind data. */ struct iommu_gpasid_bind_data { + __u32 argsz; #define IOMMU_GPASID_BIND_VERSION_1 1 __u32 version; #define IOMMU_PASID_FORMAT_INTEL_VTD 1 __u32 format; + __u32 addr_width; #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid */ __u64 flags; __u64 gpgd; __u64 hpasid; __u64 gpasid; - __u32 addr_width; - __u8 padding[12]; + __u8 padding[8]; /* Vendor specific data */ union { struct iommu_gpasid_bind_data_vtd vtd; -- 2.30.2