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 610BAC4829A for ; Tue, 13 Feb 2024 10:37:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rZq8x-0002te-10; Tue, 13 Feb 2024 05:36:04 -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 1rZq8t-0002tB-Mh for qemu-devel@nongnu.org; Tue, 13 Feb 2024 05:35:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rZq8r-0001iO-7h for qemu-devel@nongnu.org; Tue, 13 Feb 2024 05:35:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707820556; 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=RFjrhB1ldpJXgTU5OlqMUbOLWfQyxcNHDpBMUn/46ws=; b=YDcby66NEYGhEfunLXN2vJDjswVDx2LNLp467AAL3yfzPdlojZXIIa6MSy6m9ytOj5Qrqt BIhPOmjxYJ4i/W+xanpkdhYNeNhBiUMPip7n0mFjM8CeBvBe0M8bstAwtRRw9Z78Kfxl57 Ld6KGJq99F0kD64XRNFNGr7ehSlS7MY= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-543-LKg_x0g8Mq-RQ6HPLqdsFA-1; Tue, 13 Feb 2024 05:35:53 -0500 X-MC-Unique: LKg_x0g8Mq-RQ6HPLqdsFA-1 Received: by mail-ej1-f69.google.com with SMTP id a640c23a62f3a-a3a3cb0ed1aso177227766b.2 for ; Tue, 13 Feb 2024 02:35:52 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707820552; x=1708425352; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=RFjrhB1ldpJXgTU5OlqMUbOLWfQyxcNHDpBMUn/46ws=; b=Iwt3Aztg7COhig00pSx+C7HB8QocEZZkUOZ2mWOIccLfp1eYOAJihjWPltT7xXucgf SlwCVlPGdyJeC0SNd/P3AFQFvBzmKrs0E6EJm2pjUjrg6bRtf/QKIrgIavkrY7XuYr7q veL4/3gVOeE/9gn3HpTEpL6hf5NWAfGZSBSU1NfOzjSJqvLi4V2U+iE0sOrPyGZKNxO6 jd/LxVkB9aRiy/9XqMxCHAQWhaMUoBkssk3VqNgJ5HsJDX2Udbup7G9xr6M2Fp6Bm6aw 61EZQcppMhcPa7Q9YNNyMaiXiajzT2Zyia1gACfpxVF5xJJWHtymwKBnS+E7RfvOp8K2 eejw== X-Gm-Message-State: AOJu0YxbbqPHLYpqnwHqHSDdg/zMH5YQyGYpVgQO5Ep9jDDEu9st5rWt wAvX3Qn1If842UqgKXASJr4OcVKMsXL+8pgWo63C8oCvu9Vpj9an7y02kyfPs5lgiFRkbKB+0KH S2BGe4pwU7kRqU5hhctah+CXwWhI8ifmPP8G0laRuki+SbbaPtXMR X-Received: by 2002:a17:906:6845:b0:a3c:91aa:6a6d with SMTP id a5-20020a170906684500b00a3c91aa6a6dmr4525476ejs.25.1707820551925; Tue, 13 Feb 2024 02:35:51 -0800 (PST) X-Google-Smtp-Source: AGHT+IGanGJBwetyTUFVHEz+e9IhcedykuE8vYfIau+2mljZ4cgRu1EGXPaJDT4TloNQjDz4hk10EA== X-Received: by 2002:a17:906:6845:b0:a3c:91aa:6a6d with SMTP id a5-20020a170906684500b00a3c91aa6a6dmr4525444ejs.25.1707820551055; Tue, 13 Feb 2024 02:35:51 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCVvBvywEm7K5jLDZ8be5qTgWamq5hMlGlVQC4QTQbl3Z7ORtV/4+5aogBV5C5g6Dk9xEDMfPJAp3/HGnCk5WzSKuLmx96j8/X1AkGfNQKP9rB4Yp/ZZkO/dQaP41NVeX1oZA1AksROAfPelhnfVt8DCAaQcKlPmCDZLr4lgybuHJkG6gYrM8aJUyOTsKv6GBuNm3mpOL0+km1HVdbrtlqc3nK0RcEQgyagEly3PtZLgGnybSQ2+VnanZH4Lpztxo2HdQpFGvwgCzMJOxb7eTYWCzwjeFPYhigpqakFiEs0NXcxNpuYcrUTEI2pWqiKOGWGR0RpveVFAxed29+2+8A== Received: from redhat.com ([2.52.146.238]) by smtp.gmail.com with ESMTPSA id a22-20020a170906191600b00a3ca40f5045sm1148691eje.72.2024.02.13.02.35.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Feb 2024 02:35:50 -0800 (PST) Date: Tue, 13 Feb 2024 05:35:45 -0500 From: "Michael S. Tsirkin" To: Eric Auger Cc: eric.auger.pro@gmail.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, jean-philippe@linaro.org, peter.maydell@linaro.org, clg@redhat.com, zhenzhong.duan@intel.com, yanghliu@redhat.com, alex.williamson@redhat.com, jasowang@redhat.com Subject: Re: [PATCH v3 0/3] VIRTIO-IOMMU: Introduce an aw-bits option Message-ID: <20240213053502-mutt-send-email-mst@kernel.org> References: <20240208101128.655167-1-eric.auger@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240208101128.655167-1-eric.auger@redhat.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.774, 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_H2=-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 On Thu, Feb 08, 2024 at 11:10:16AM +0100, Eric Auger wrote: > In [1] and [2] we attempted to fix a case where a VFIO-PCI device > protected with a virtio-iommu is assigned to an x86 guest. On x86 > the physical IOMMU may have an address width (gaw) of 39 or 48 bits > whereas the virtio-iommu exposes a 64b input address space by default. > Hence the guest may try to use the full 64b space and DMA MAP > failures may be encountered. To work around this issue we endeavoured > to pass usable host IOVA regions (excluding the out of range space) from > VFIO to the virtio-iommu device so that the virtio-iommu driver can > query those latter during the probe request and let the guest iommu > kernel subsystem carve them out. > > However if there are several devices in the same iommu group, > only the reserved regions of the first one are taken into > account by the iommu subsystem of the guest. This generally > works on baremetal because devices are not going to > expose different reserved regions. However in our case, this > may prevent from taking into account the host iommu geometry. > > So the simplest solution to this problem looks to introduce an > input address width option, aw-bits, which matches what is > done on the intel-iommu. By default, from now on it is set > to 39 bits with pc_q35 and 48 with arm virt. This replaces the > previous default value of 64b. So we need to introduce a compat > for machines older than 9.0 to behave similarly. We use > hw_compat_8_2 to acheive that goal. > > Outstanding series [2] remains useful to let resv regions beeing > communicated on time before the probe request. > > [1] [PATCH v4 00/12] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space > https://lore.kernel.org/all/20231019134651.842175-1-eric.auger@redhat.com/ > - This is merged - > > [2] [RFC 0/7] VIRTIO-IOMMU/VFIO: Fix host iommu geometry handling for hotplugged devices > https://lore.kernel.org/all/20240117080414.316890-1-eric.auger@redhat.com/ > - This is pending for review on the ML - > > This series can be found at: > https://github.com/eauger/qemu/tree/virtio-iommu-aw-bits-v3 > previous > https://github.com/eauger/qemu/tree/virtio-iommu-aw-bits-v2 > > Applied on top of [3] > [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/ So, I applied this without that patch until we agree whether there are compat issues in that one. Seems to work without or did I miss anything? > History: > v2 -> v3: > - Collected Zhenzhong and Cédric's R-b + Yanghang's T-b > - use &error_abort instead of NULL error handle > on object_property_get_uint() call (Cédric) > - use VTD_HOST_AW_39BIT (Cédric) > > v1 -> v2 > - Limit aw to 48b on ARM > - Check aw is within [32,64] > - Use hw_compat_8_2 > > > Eric Auger (3): > virtio-iommu: Add an option to define the input range width > virtio-iommu: Trace domain range limits as unsigned int > hw: Set virtio-iommu aw-bits default value on pc_q35 and arm virt > > include/hw/virtio/virtio-iommu.h | 1 + > hw/arm/virt.c | 6 ++++++ > hw/core/machine.c | 5 ++++- > hw/i386/pc.c | 6 ++++++ > hw/virtio/virtio-iommu.c | 7 ++++++- > hw/virtio/trace-events | 2 +- > 6 files changed, 24 insertions(+), 3 deletions(-) > > -- > 2.41.0