From patchwork Tue Feb 27 16:55:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 13574137 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 CE1C7C5478C for ; Tue, 27 Feb 2024 16:59:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rf0mE-0005MY-I3; Tue, 27 Feb 2024 11:57:58 -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 1rf0mD-0005MI-GL for qemu-devel@nongnu.org; Tue, 27 Feb 2024 11:57:57 -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 1rf0mC-000560-0h for qemu-devel@nongnu.org; Tue, 27 Feb 2024 11:57:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709053075; 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=KTplvI6/gFdX2/UhXfHC90lA0fM8hwlb4jQEj8TJeWM=; b=AT8nIjvZXKveHMEc5+PSIzlvVD4vTbcT1asLIVBwDmK0DzFghLlQyZmtvLOhsuOoxq3vPN hjSvNutr83Np/jwlOrpOTstjjUiD9RPxfJP71twgiYKS6Q+cJ968d1hBwKCNWzFeN4K17Q mwa8p6Zo91GOvbXnkq9AyGJ0Sy7zDuA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-647-LJe9LkuhNzeHeTYa9gJSng-1; Tue, 27 Feb 2024 11:57:52 -0500 X-MC-Unique: LJe9LkuhNzeHeTYa9gJSng-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 AC047185A785; Tue, 27 Feb 2024 16:57:51 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.39.193.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE88B2166B5D; Tue, 27 Feb 2024 16:57:47 +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 v6 3/3] virtio-iommu: Change the default granule to the host page size Date: Tue, 27 Feb 2024 17:55:50 +0100 Message-ID: <20240227165730.14099-4-eric.auger@redhat.com> In-Reply-To: <20240227165730.14099-1-eric.auger@redhat.com> References: <20240227165730.14099-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; 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=-0.088, 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 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. Set the granule property to "host" and introduce a new compat. The page size mask used before 9.0 was qemu_target_page_mask(). Since the virtio-iommu currently only supports x86_64 and aarch64, this matched a 4KB granule. 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". In that case the workaround is to request 4K granule. 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. Signed-off-by: Eric Auger Reviewed-by: Philippe Mathieu-Daudé --- v4 -> v5 - use low case, mandated by the jason qapi --- hw/core/machine.c | 1 + hw/virtio/virtio-iommu.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index 70ac96954c..56f38b6579 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -35,6 +35,7 @@ GlobalProperty hw_compat_8_2[] = { { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "64" }, + { TYPE_VIRTIO_IOMMU_PCI, "granule", "4k" }, }; const size_t hw_compat_8_2_len = G_N_ELEMENTS(hw_compat_8_2); diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index 33e0520bc8..6831446e29 100644 --- a/hw/virtio/virtio-iommu.c +++ b/hw/virtio/virtio-iommu.c @@ -1548,7 +1548,7 @@ static Property virtio_iommu_properties[] = { DEFINE_PROP_BOOL("boot-bypass", VirtIOIOMMU, boot_bypass, true), DEFINE_PROP_UINT8("aw-bits", VirtIOIOMMU, aw_bits, 0), DEFINE_PROP_GRANULE_MODE("granule", VirtIOIOMMU, granule_mode, - GRANULE_MODE_4K), + GRANULE_MODE_HOST), DEFINE_PROP_END_OF_LIST(), };