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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4FAF8C5478A for ; Wed, 21 Feb 2024 21:00:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rctgq-0000qL-43; Wed, 21 Feb 2024 15:59:40 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rctgn-0000q5-3v for qemu-devel@nongnu.org; Wed, 21 Feb 2024 15:59:37 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rctgk-0005nY-Ks for qemu-devel@nongnu.org; Wed, 21 Feb 2024 15:59:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708549173; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=NdbAglMEp6apZkI73sm61ThlRrgopBdcdsCQVathT14=; b=C+20laCLFiCHiYF5Yh+fYnYzQRPbdG5rc/qhc5RHtJEy/retJm/lvtL/7pwvP3SE8EPoGR irZ1er7kFnsAbqKxCWy7widY7D6Adi5QXmuHkytTRKLZBazF5X8rWNIQnveFu+mWStRzFQ /nWBtVfW142gztTW3q8emw8Aaqb5ZIs= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-376--1emY2reMSalFSIIC4we6g-1; Wed, 21 Feb 2024 15:59:31 -0500 X-MC-Unique: -1emY2reMSalFSIIC4we6g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 580E91C05AC4; Wed, 21 Feb 2024 20:59:31 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.39.195.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B5E014F0; Wed, 21 Feb 2024 20:59:27 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, mst@redhat.com, jean-philippe@linaro.org, peter.maydell@linaro.org, clg@redhat.com, yanghliu@redhat.com Cc: alex.williamson@redhat.com, zhenzhong.duan@intel.com, jasowang@redhat.com, pbonzini@redhat.com, berrange@redhat.com Subject: [PATCH v3 0/3] VIRTIO-IOMMU: Set default granule to host page size Date: Wed, 21 Feb 2024 21:58:25 +0100 Message-ID: <20240221205926.40066-1-eric.auger@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eric.auger@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.05, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org We used to set the default granule to 4KB but with VFIO assignment it makes more sense to use the actual host page size. Indeed when hotplugging a VFIO device protected by a virtio-iommu on a 64kB/64kB host/guest config, we current get a qemu crash: "vfio: DMA mapping failed, unable to continue" This is due to the hot-attached VFIO device calling memory_region_iommu_set_page_size_mask() with 64kB granule whereas the virtio-iommu granule was already frozen to 4KB on machine init done. Introduce a new granule property and set this latter to "host" and introduce a new compat. Note that the new default will prevent 4kB guest on 64kB host because the granule will be set to 64kB which would be larger than the guest page size. In that situation, the virtio-iommu driver fails on viommu_domain_finalise() with "granule 0x10000 larger than system page size 0x1000". The current limitation of global granule in the virtio-iommu should be removed and turned into per domain granule. But until we get this upgraded, this new default is probably better because I don't think anyone is currently interested in running a 4KB page size guest with virtio-iommu on a 64KB host. However supporting 64kB guest on 64kB host with virtio-iommu and VFIO looks a more important feature. This series can be found at: https://github.com/eauger/qemu/tree/granule-v1 Previous version: [PATCH v2] virtio-iommu: Use qemu_real_host_page_mask as default page_size_mask https://lore.kernel.org/all/20240117132039.332273-1-eric.auger@redhat.com/ Applied on top of [PATCH v5 0/4] VIRTIO-IOMMU: Introduce an aw-bits option https://lore.kernel.org/all/20240215084315.863897-1-eric.auger@redhat.com/ History: v2 -> v3 - introduce a dedicated granule option to handle the compat Eric Auger (3): qdev: Add a granule_mode property virtio-iommu: Add a granule property virtio-iommu: Change the default granule to the host page size include/hw/qdev-properties-system.h | 3 +++ include/hw/virtio/virtio-iommu.h | 11 ++++++++++ hw/core/machine.c | 1 + hw/core/qdev-properties-system.c | 15 +++++++++++++ hw/virtio/virtio-iommu.c | 34 ++++++++++++++++++++++++++--- qemu-options.hx | 3 +++ 6 files changed, 64 insertions(+), 3 deletions(-) -- 2.41.0