From patchwork Wed Feb 21 20:58:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 13566281 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 48B29C48BEB for ; Wed, 21 Feb 2024 21:00:30 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rctgz-00012S-IF; Wed, 21 Feb 2024 15:59:49 -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 1rctgy-00011y-2b for qemu-devel@nongnu.org; Wed, 21 Feb 2024 15:59:48 -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 1rctgw-0005os-JT for qemu-devel@nongnu.org; Wed, 21 Feb 2024 15:59:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708549185; 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: in-reply-to:in-reply-to:references:references; bh=e9KBBuGHB08NJ+ZIcJCgJrqBaD7JtOUqxzBEKSWmsBs=; b=cb8b6J/YjNN+RnUsLhPGvT0vhPzRJKDItFyuQTILWuVZhDUB35AS/fX6QUpC+ffYf1zl6/ RaxZEtY+xCYiHGskpC5zgtkwO5BlOEqN4c5qN1U3kfBLL4PRp7BZFahl6LD54yV9zGIXPR /PIoX0yNRNTOhVVjs1WFM+N64L+ujZ0= 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-531-hAKhyTIjNCmc5yoEK-pgJg-1; Wed, 21 Feb 2024 15:59:42 -0500 X-MC-Unique: hAKhyTIjNCmc5yoEK-pgJg-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 E635985A589; Wed, 21 Feb 2024 20:59:41 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.39.195.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA8122BE; Wed, 21 Feb 2024 20:59:38 +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 3/3] virtio-iommu: Change the default granule to the host page size Date: Wed, 21 Feb 2024 21:58:28 +0100 Message-ID: <20240221205926.40066-4-eric.auger@redhat.com> In-Reply-To: <20240221205926.40066-1-eric.auger@redhat.com> References: <20240221205926.40066-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 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=-0.05, 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_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. 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. Signed-off-by: Eric Auger --- 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..38851df4b8 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 1eded09134..0a6e2e6c9f 100644 --- a/hw/virtio/virtio-iommu.c +++ b/hw/virtio/virtio-iommu.c @@ -1554,7 +1554,7 @@ 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(), };