From patchwork Tue Feb 2 04:13:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 12060609 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 685FBC433E0 for ; Tue, 2 Feb 2021 04:21:10 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E71EB64ED9 for ; Tue, 2 Feb 2021 04:21:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E71EB64ED9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l6nBd-0007KD-0a for qemu-devel@archiver.kernel.org; Mon, 01 Feb 2021 23:21:09 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46004) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6n4U-00069E-Fk; Mon, 01 Feb 2021 23:13:46 -0500 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:38949 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6n4R-0004zI-Sr; Mon, 01 Feb 2021 23:13:46 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4DVBJ042nvz9tlG; Tue, 2 Feb 2021 15:13:20 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1612239200; bh=kIonU8SS9uqw0f6IgA4IJrI2gSOoAYwIy/ciHXZai4o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/wUqoA4yNdX1eHOsJ/9p/nVHiCS5VE1aqXkXDnrCqnQ/v9q014bmFf/703OQhfbv +EU/D2AM5SeuKf2ZEz9a3T9ZSk5wmbjZZwT8fXXbPvAdtoo3pvR/WVtHlzbMM/mNUr ZUkVIFy+EExV/McXFTxdfFGyXfdmKcP30Cd79/W8= From: David Gibson To: dgilbert@redhat.com, pair@us.ibm.com, qemu-devel@nongnu.org, brijesh.singh@amd.com, pasic@linux.ibm.com Subject: [PATCH v8 12/13] confidential guest support: Alter virtio default properties for protected guests Date: Tue, 2 Feb 2021 15:13:14 +1100 Message-Id: <20210202041315.196530-13-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210202041315.196530-1-david@gibson.dropbear.id.au> References: <20210202041315.196530-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com, Cornelia Huck , berrange@redhat.com, mst@redhat.com, kvm@vger.kernel.org, David Hildenbrand , jun.nakajima@intel.com, mtosatti@redhat.com, richard.henderson@linaro.org, mdroth@linux.vnet.ibm.com, Eduardo Habkost , Greg Kurz , pragyansri.pathi@intel.com, qemu-s390x@nongnu.org, frankja@linux.ibm.com, qemu-ppc@nongnu.org, andi.kleen@intel.com, pbonzini@redhat.com, borntraeger@de.ibm.com, David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The default behaviour for virtio devices is not to use the platforms normal DMA paths, but instead to use the fact that it's running in a hypervisor to directly access guest memory. That doesn't work if the guest's memory is protected from hypervisor access, such as with AMD's SEV or POWER's PEF. So, if a confidential guest mechanism is enabled, then apply the iommu_platform=on option so it will go through normal DMA mechanisms. Those will presumably have some way of marking memory as shared with the hypervisor or hardware so that DMA will work. Signed-off-by: David Gibson Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Cornelia Huck Reviewed-by: Greg Kurz --- hw/core/machine.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index 94194ab82d..497949899b 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -33,6 +33,8 @@ #include "migration/global_state.h" #include "migration/vmstate.h" #include "exec/confidential-guest-support.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_2[] = {}; const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2); @@ -1196,6 +1198,17 @@ void machine_run_board_init(MachineState *machine) * areas. */ machine_set_mem_merge(OBJECT(machine), false, &error_abort); + + /* + * Virtio devices can't count on directly accessing guest + * memory, so they need iommu_platform=on to use normal DMA + * mechanisms. That requires also disabling legacy virtio + * support for those virtio pci devices which allow it. + */ + object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy", + "on", true); + object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform", + "on", false); } machine_class->init(machine);