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=-11.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 89EC9C433E0 for ; Tue, 2 Feb 2021 17:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 454E464F94 for ; Tue, 2 Feb 2021 17:25:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237512AbhBBRZV (ORCPT ); Tue, 2 Feb 2021 12:25:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:58927 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236982AbhBBRXI (ORCPT ); Tue, 2 Feb 2021 12:23:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612286502; 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=rtng0npx+0yDN+RLW8SrKhZZ+4kV4zvwZY21R7GQprE=; b=GD2Rbbow20Gf/47q35dWwd784+1Q8PkaoFOO4yVaJUzr29t/XlvMg2duLmwaRn1QlXMhbB d1GR5rs87B+b4oBeBKe/z24WUnvsEHWpjL9P7zKAzQn/cwebyesTHdogQ9EG3iR24SHgUG unbHFD2seFiIaU9mKXOtfAZYK9f7J+A= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-532-ZWKH4kK_NJaI_lc0RJdl-g-1; Tue, 02 Feb 2021 12:21:39 -0500 X-MC-Unique: ZWKH4kK_NJaI_lc0RJdl-g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0D6AA106BC6B; Tue, 2 Feb 2021 17:21:38 +0000 (UTC) Received: from omen.home.shazbot.org (ovpn-112-255.phx2.redhat.com [10.3.112.255]) by smtp.corp.redhat.com (Postfix) with ESMTP id BA7DA6EF46; Tue, 2 Feb 2021 17:21:37 +0000 (UTC) Date: Tue, 2 Feb 2021 10:21:37 -0700 From: Alex Williamson To: Steve Sistare Cc: kvm@vger.kernel.org, Cornelia Huck , Kirti Wankhede Subject: Re: [PATCH V3 0/9] vfio virtual address update Message-ID: <20210202102137.1cf74d8f@omen.home.shazbot.org> In-Reply-To: <1611939252-7240-1-git-send-email-steven.sistare@oracle.com> References: <1611939252-7240-1-git-send-email-steven.sistare@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, 29 Jan 2021 08:54:03 -0800 Steve Sistare wrote: > Add interfaces that allow the underlying memory object of an iova range > to be mapped to a new virtual address in the host process: > > - VFIO_DMA_UNMAP_FLAG_VADDR for VFIO_IOMMU_UNMAP_DMA > - VFIO_DMA_MAP_FLAG_VADDR flag for VFIO_IOMMU_MAP_DMA > - VFIO_UPDATE_VADDR for VFIO_CHECK_EXTENSION > - VFIO_DMA_UNMAP_FLAG_ALL for VFIO_IOMMU_UNMAP_DMA > - VFIO_UNMAP_ALL for VFIO_CHECK_EXTENSION > > Unmap-vaddr invalidates the host virtual address in an iova range and blocks > vfio translation of host virtual addresses, but DMA to already-mapped pages > continues. Map-vaddr updates the base VA and resumes translation. The > implementation supports iommu type1 and mediated devices. Unmap-all allows > all ranges to be unmapped or invalidated in a single ioctl, which simplifies > userland code. > > This functionality is necessary for live update, in which a host process > such as qemu exec's an updated version of itself, while preserving its > guest and vfio devices. The process blocks vfio VA translation, exec's > its new self, mmap's the memory object(s) underlying vfio object, updates > the VA, and unblocks translation. For a working example that uses these > new interfaces, see the QEMU patch series "[PATCH V2] Live Update" at > https://lore.kernel.org/qemu-devel/1609861330-129855-1-git-send-email-steven.sistare@oracle.com > > Patches 1-3 define and implement the flag to unmap all ranges. > Patches 4-6 define and implement the flags to update vaddr. > Patches 7-9 add blocking to complete the implementation. > > Changes in V2: > - define a flag for unmap all instead of special range values > - define the VFIO_UNMAP_ALL extension > - forbid the combination of unmap-all and get-dirty-bitmap > - unwind in unmap on vaddr error > - add a new function to find first dma in a range instead of modifying > an existing function > - change names of update flags > - fix concurrency bugs due to iommu lock being dropped > - call down from from vfio to a new backend interface instead of up from > driver to detect container close > - use wait/wake instead of sleep and polling > - refine the uapi specification > - split patches into vfio vs type1 > > Changes in V3: > - add vaddr_invalid_count to fix pin_pages race with unmap > - refactor the wait helper functions > - traverse dma entries more efficiently in unmap > - check unmap flag conflicts more explicitly > - rename some local variables and functions > > Steve Sistare (9): > vfio: option to unmap all > vfio/type1: unmap cleanup > vfio/type1: implement unmap all > vfio: interfaces to update vaddr > vfio/type1: massage unmap iteration > vfio/type1: implement interfaces to update vaddr > vfio: iommu driver notify callback > vfio/type1: implement notify callback > vfio/type1: block on invalid vaddr > > drivers/vfio/vfio.c | 5 + > drivers/vfio/vfio_iommu_type1.c | 251 +++++++++++++++++++++++++++++++++++----- > include/linux/vfio.h | 5 + > include/uapi/linux/vfio.h | 27 +++++ > 4 files changed, 256 insertions(+), 32 deletions(-) > Applied to vfio next branch for v5.12 with discussed changes and Connie's R-b. Thanks, Alex