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=-8.5 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,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 044E0C43331 for ; Tue, 31 Mar 2020 19:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1A46208E0 for ; Tue, 31 Mar 2020 19:09:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="i70eDpzG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726411AbgCaTJD (ORCPT ); Tue, 31 Mar 2020 15:09:03 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:11526 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726295AbgCaTJD (ORCPT ); Tue, 31 Mar 2020 15:09:03 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 31 Mar 2020 12:07:26 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Tue, 31 Mar 2020 12:09:02 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Tue, 31 Mar 2020 12:09:02 -0700 Received: from [10.40.162.111] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 31 Mar 2020 19:08:53 +0000 Subject: Re: [PATCH v17 Kernel 6/7] vfio iommu: Adds flag to indicate dirty pages tracking capability support To: Alex Williamson CC: , , , , , , , , , , , , , , , , , , , , References: <1585587044-2408-1-git-send-email-kwankhede@nvidia.com> <1585587044-2408-7-git-send-email-kwankhede@nvidia.com> <20200330145814.32d9b652@w520.home> X-Nvconfidentiality: public From: Kirti Wankhede Message-ID: <6c6e6625-6dfd-d885-23fe-511744816d5b@nvidia.com> Date: Wed, 1 Apr 2020 00:38:49 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200330145814.32d9b652@w520.home> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; 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=1585681646; bh=+yRWf/dhtXvw/FAHRSSc0ZeH7kuo6HPCnZdE9zKjc0M=; 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=i70eDpzGIkE90JVwCF92NHeLs5KCZXzNyiNCBffWHIw5ILFL8dbHxySZwtXKoN5j0 qPhA1SX8fIuw1UbJwdiUPkE2jY3ti4qY0FXNz0s+9aptIIwBdh1054hbl8kxOF9vME ICGngr/G+MkI9W77J7jbL3QJMvSsEJO4CFtqB3E7Hx6HfYm87Yvcd6eCUBo7gfx4o7 DxPxccSQk49IAj8BG8xA/hVVlQDxM6HqZQfrQ/Xc1msSFwoARDrKWE3Pi2i+B9gq0R tGeD/mdUjsiYzOUA97jJ/1sX2Jg6x83OPFc8STgwgyxY8DlsG7MeE2jRHI49dc5UUS gF4m8C2N1QMig== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 3/31/2020 2:28 AM, Alex Williamson wrote: > On Mon, 30 Mar 2020 22:20:43 +0530 > Kirti Wankhede wrote: > >> Flag VFIO_IOMMU_INFO_DIRTY_PGS in VFIO_IOMMU_GET_INFO indicates that driver >> support dirty pages tracking. >> >> Signed-off-by: Kirti Wankhede >> Reviewed-by: Neo Jia >> --- >> drivers/vfio/vfio_iommu_type1.c | 3 ++- >> include/uapi/linux/vfio.h | 5 +++-- >> 2 files changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c >> index 266550bd7307..9fe12b425976 100644 >> --- a/drivers/vfio/vfio_iommu_type1.c >> +++ b/drivers/vfio/vfio_iommu_type1.c >> @@ -2390,7 +2390,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, >> info.cap_offset = 0; /* output, no-recopy necessary */ >> } >> >> - info.flags = VFIO_IOMMU_INFO_PGSIZES; >> + info.flags = VFIO_IOMMU_INFO_PGSIZES | >> + VFIO_IOMMU_INFO_DIRTY_PGS; >> >> info.iova_pgsizes = vfio_pgsize_bitmap(iommu); >> >> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h >> index e3cbf8b78623..0fe7c9a6f211 100644 >> --- a/include/uapi/linux/vfio.h >> +++ b/include/uapi/linux/vfio.h >> @@ -985,8 +985,9 @@ struct vfio_device_feature { >> struct vfio_iommu_type1_info { >> __u32 argsz; >> __u32 flags; >> -#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */ >> -#define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */ >> +#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */ >> +#define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */ >> +#define VFIO_IOMMU_INFO_DIRTY_PGS (1 << 2) /* supports dirty page tracking */ >> __u64 iova_pgsizes; /* Bitmap of supported page sizes */ >> __u32 cap_offset; /* Offset within info struct of first cap */ >> }; > > > As I just mentioned in my reply to Yan, I'm wondering if > VFIO_CHECK_EXTENSION would be a better way to expose this. The > difference is relatively trivial, but currently the only flag > set by VFIO_IOMMU_GET_INFO is to indicate the presence of a field in > the returned structure. I think this is largely true of other INFO > ioctls within vfio as well and we're already using the > VFIO_CHECK_EXTENSION ioctl to check supported IOMMU models, and IOMMU > cache coherency. We'd simply need to define a VFIO_DIRTY_PGS_IOMMU > value (9) and return 1 for that case. Then when we enable support for > dirt pages that can span multiple mappings, we can add a v2 extensions, > or "MULTI" variant of this extension, since it should be backwards > compatible. > > The v2/multi version will again require that the user provide a zero'd > bitmap, but I don't think that should be a problem as part of the > definition of that version (we won't know if the user is using v1 or > v2, but a v1 user should only retrieve bitmaps that exactly match > existing mappings, where all bits will be written). Thanks, > > Alex > I look at these two ioctls as : VFIO_CHECK_EXTENSION is used to get IOMMU type, while VFIO_IOMMU_GET_INFO is used to get properties of a particular IOMMU type, right? Then I think VFIO_IOMMU_INFO_DIRTY_PGS should be part of VFIO_IOMMU_GET_INFO and when we add code for v2/multi, a flag should be added to VFIO_IOMMU_GET_INFO. Thanks, Kirti