From patchwork Fri Dec 4 05:44:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 11950657 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 C8745C4361A for ; Fri, 4 Dec 2020 05:49:44 +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 2686D224DF for ; Fri, 4 Dec 2020 05:49:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2686D224DF 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]:47924 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kl3yR-0003dp-1l for qemu-devel@archiver.kernel.org; Fri, 04 Dec 2020 00:49:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56862) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kl3tX-0004EV-Rn; Fri, 04 Dec 2020 00:44:39 -0500 Received: from bilbo.ozlabs.org ([203.11.71.1]:46815 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 1kl3tV-00006I-9r; Fri, 04 Dec 2020 00:44:39 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4CnM8j2ctRz9sWD; Fri, 4 Dec 2020 16:44:21 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1607060661; bh=VJ+LxQJOkUVbhfEUmAX9VA/bXYtOMYSQX40lQmDmveM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n/hPt3e/EfOiifh/tLDcORyx4cp37QBDhJC+dZIUX84hluIDTzl9WSZvn2hpjXPci iutHioNHKh8PvMKfetFpm85FIdF3HrtE9XlCKmt8JHPB0ePHauUOLRQyH6eq8Y1d0P K3T3aL3fPzr4KyCGKJ9rj8SPkzOU8TG8bRBuz+E0= From: David Gibson To: pair@us.ibm.com, pbonzini@redhat.com, frankja@linux.ibm.com, brijesh.singh@amd.com, dgilbert@redhat.com, qemu-devel@nongnu.org Subject: [for-6.0 v5 12/13] securable guest memory: Alter virtio default properties for protected guests Date: Fri, 4 Dec 2020 16:44:14 +1100 Message-Id: <20201204054415.579042-13-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201204054415.579042-1-david@gibson.dropbear.id.au> References: <20201204054415.579042-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Received-SPF: pass client-ip=203.11.71.1; 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, cohuck@redhat.com, berrange@redhat.com, Eduardo Habkost , kvm@vger.kernel.org, "Michael S. Tsirkin" , Richard Henderson , Marcelo Tosatti , david@redhat.com, mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, borntraeger@de.ibm.com, qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, David Gibson , rth@twiddle.net 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 securable guest memory 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 --- hw/core/machine.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index a67a27d03c..d16273d75d 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -28,6 +28,8 @@ #include "hw/mem/nvdimm.h" #include "migration/vmstate.h" #include "exec/securable-guest-memory.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_1[] = { { "vhost-scsi", "num_queues", "1"}, @@ -1169,6 +1171,17 @@ 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);