From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6860DC432C3 for ; Wed, 13 Nov 2019 19:37:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC56B206DC for ; Wed, 13 Nov 2019 19:37:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="lINcAqrg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726173AbfKMThg (ORCPT ); Wed, 13 Nov 2019 14:37:36 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:2572 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726120AbfKMThg (ORCPT ); Wed, 13 Nov 2019 14:37:36 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 13 Nov 2019 11:37:37 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 13 Nov 2019 11:37:34 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 13 Nov 2019 11:37:34 -0800 Received: from [10.25.73.195] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 13 Nov 2019 19:37:25 +0000 Subject: Re: [PATCH v9 Kernel 2/5] vfio iommu: Add ioctl defination to get dirty pages bitmap. To: Alex Williamson CC: , , , , , , , , , , , , , , , , , , , , References: <1573578220-7530-1-git-send-email-kwankhede@nvidia.com> <1573578220-7530-3-git-send-email-kwankhede@nvidia.com> <20191112153020.71406c44@x1.home> X-Nvconfidentiality: public From: Kirti Wankhede Message-ID: <324ce4f8-d655-ee37-036c-fc9ef9045bef@nvidia.com> Date: Thu, 14 Nov 2019 01:07:21 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20191112153020.71406c44@x1.home> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573673857; bh=6fNZc2mHwEswrolJj1VDa99wf4sYflIbMrzvc45iAFs=; h=X-PGP-Universal:Subject:To:CC:References:X-Nvconfidentiality:From: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=lINcAqrguOlRieumuvDf33LJlToXpndTmzQVE7Umbdg2fukbs/FsQuO8LG09mLMbT dF/mhOYz0CbIHm+Z7Fldewq+TzeeQ4uaSRSgJ2wZ+3HEteE0hYnhBcXgZwlDo384yv Tw723jIeUDyHfCS19eTJtlCVaBedNHi3LPT+0PUCMruh4YkMQhNSimTKBdtFuuB4nw JSq6cWas/z26CqW2c31HLs9fS2vWKZGW78PEp4ssVBETLzLHpG1VuY7fs0XTc8aKyY PpaWTWRGSanA4VBu1VUlvGmtomCLNqtMmGucf3+E0BI8TQ09EikX3n2JPWbmL/NBY8 uN1SsDxMiLAUQ== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 11/13/2019 4:00 AM, Alex Williamson wrote: > On Tue, 12 Nov 2019 22:33:37 +0530 > Kirti Wankhede wrote: > >> All pages pinned by vendor driver through vfio_pin_pages API should be >> considered as dirty during migration. IOMMU container maintains a list of >> all such pinned pages. Added an ioctl defination to get bitmap of such > > definition > >> pinned pages for requested IO virtual address range. > > Additionally, all mapped pages are considered dirty when physically > mapped through to an IOMMU, modulo we discussed devices opting in to > per page pinning to indicate finer granularity with a TBD mechanism to > figure out if any non-opt-in devices remain. > You mean, in case of device direct assignment (device pass through)? >> Signed-off-by: Kirti Wankhede >> Reviewed-by: Neo Jia >> --- >> include/uapi/linux/vfio.h | 23 +++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h >> index 35b09427ad9f..6fd3822aa610 100644 >> --- a/include/uapi/linux/vfio.h >> +++ b/include/uapi/linux/vfio.h >> @@ -902,6 +902,29 @@ struct vfio_iommu_type1_dma_unmap { >> #define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15) >> #define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16) >> >> +/** >> + * VFIO_IOMMU_GET_DIRTY_BITMAP - _IOWR(VFIO_TYPE, VFIO_BASE + 17, >> + * struct vfio_iommu_type1_dirty_bitmap) >> + * >> + * IOCTL to get dirty pages bitmap for IOMMU container during migration. >> + * Get dirty pages bitmap of given IO virtual addresses range using >> + * struct vfio_iommu_type1_dirty_bitmap. Caller sets argsz, which is size of >> + * struct vfio_iommu_type1_dirty_bitmap. User should allocate memory to get >> + * bitmap and should set size of allocated memory in bitmap_size field. >> + * One bit is used to represent per page consecutively starting from iova >> + * offset. Bit set indicates page at that offset from iova is dirty. >> + */ >> +struct vfio_iommu_type1_dirty_bitmap { >> + __u32 argsz; >> + __u32 flags; >> + __u64 iova; /* IO virtual address */ >> + __u64 size; /* Size of iova range */ >> + __u64 bitmap_size; /* in bytes */ > > This seems redundant. We can calculate the size of the bitmap based on > the iova size. > But in kernel space, we need to validate the size of memory allocated by user instead of assuming user is always correct, right? >> + void __user *bitmap; /* one bit per page */ > > Should we define that as a __u64* to (a) help with the size > calculation, and (b) assure that we can use 8-byte ops on it? > > However, who defines page size? Is it necessarily the processor page > size? A physical IOMMU may support page sizes other than the CPU page > size. It might be more important to indicate the expected page size > than the bitmap size. Thanks, > I see in QEMU and in vfio_iommu_type1 module, page sizes considered for mapping are CPU page size, 4K. Do we still need to have such argument? Thanks, Kirti > Alex > >> +}; >> + >> +#define VFIO_IOMMU_GET_DIRTY_BITMAP _IO(VFIO_TYPE, VFIO_BASE + 17) >> + >> /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ >> >> /* >