From patchwork Mon Sep 18 20:56:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13390484 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39C5EC46CA1 for ; Mon, 18 Sep 2023 20:57:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230211AbjIRU5d (ORCPT ); Mon, 18 Sep 2023 16:57:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230100AbjIRU5X (ORCPT ); Mon, 18 Sep 2023 16:57:23 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E10EB114 for ; Mon, 18 Sep 2023 13:56:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695070588; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BLJVBc/pzccugePJdqT4Or41HsOp/4DxwdzX8mZIktY=; b=GBuU2VNFIa7x2Rn1hpoRmVzTX+CZwhpfeD8MYztrOgaefg7qqz/Tnmr2oNSRcaNUf8dqG4 jxCL2iy5w4gLIcKN/QGoyU71frml1AZfiJ3b6ETIbwgtXGq560Af38NwEGkSqi0TWcQTES Fz0hSHN188hJJ7bfX7NcSnEUQ+oAueE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-150-CjqjOcAdPzOEQ4KcAmIYmg-1; Mon, 18 Sep 2023 16:56:22 -0400 X-MC-Unique: CjqjOcAdPzOEQ4KcAmIYmg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 96B51800883; Mon, 18 Sep 2023 20:56:21 +0000 (UTC) Received: from localhost (unknown [10.39.195.53]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1BD9040C2064; Mon, 18 Sep 2023 20:56:20 +0000 (UTC) From: Stefan Hajnoczi To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jason Gunthorpe , Alex Williamson , David Laight , "Tian, Kevin" , Stefan Hajnoczi , Jason Gunthorpe , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= Subject: [PATCH v3 1/3] vfio: trivially use __aligned_u64 for ioctl structs Date: Mon, 18 Sep 2023 16:56:15 -0400 Message-ID: <20230918205617.1478722-2-stefanha@redhat.com> In-Reply-To: <20230918205617.1478722-1-stefanha@redhat.com> References: <20230918205617.1478722-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org u64 alignment behaves differently depending on the architecture and so offers __aligned_u64 to achieve consistent behavior in kernel<->userspace ABIs. There are structs in that can trivially be updated to __aligned_u64 because the struct sizes are multiples of 8 bytes. There is no change in memory layout on any CPU architecture and therefore this change is safe. The commits that follow this one handle the trickier cases where explanation about ABI breakage is necessary. Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Kevin Tian Signed-off-by: Stefan Hajnoczi --- include/uapi/linux/vfio.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index afc1369216d9..4dc0182c6bcb 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -277,8 +277,8 @@ struct vfio_region_info { #define VFIO_REGION_INFO_FLAG_CAPS (1 << 3) /* Info supports caps */ __u32 index; /* Region index */ __u32 cap_offset; /* Offset within info struct of first cap */ - __u64 size; /* Region size (bytes) */ - __u64 offset; /* Region offset from start of device fd */ + __aligned_u64 size; /* Region size (bytes) */ + __aligned_u64 offset; /* Region offset from start of device fd */ }; #define VFIO_DEVICE_GET_REGION_INFO _IO(VFIO_TYPE, VFIO_BASE + 8) @@ -294,8 +294,8 @@ struct vfio_region_info { #define VFIO_REGION_INFO_CAP_SPARSE_MMAP 1 struct vfio_region_sparse_mmap_area { - __u64 offset; /* Offset of mmap'able area within region */ - __u64 size; /* Size of mmap'able area */ + __aligned_u64 offset; /* Offset of mmap'able area within region */ + __aligned_u64 size; /* Size of mmap'able area */ }; struct vfio_region_info_cap_sparse_mmap { @@ -450,9 +450,9 @@ struct vfio_device_migration_info { VFIO_DEVICE_STATE_V1_RESUMING) __u32 reserved; - __u64 pending_bytes; - __u64 data_offset; - __u64 data_size; + __aligned_u64 pending_bytes; + __aligned_u64 data_offset; + __aligned_u64 data_size; }; /* @@ -476,7 +476,7 @@ struct vfio_device_migration_info { struct vfio_region_info_cap_nvlink2_ssatgt { struct vfio_info_cap_header header; - __u64 tgt; + __aligned_u64 tgt; }; /* @@ -1449,7 +1449,7 @@ struct vfio_iommu_type1_info { __u32 flags; #define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */ #define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */ - __u64 iova_pgsizes; /* Bitmap of supported page sizes */ + __aligned_u64 iova_pgsizes; /* Bitmap of supported page sizes */ __u32 cap_offset; /* Offset within info struct of first cap */ __u32 pad; };