From patchwork Fri Jul 24 02:57:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 11681943 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3C5BA6C1 for ; Fri, 24 Jul 2020 03:02:34 +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 10AD420737 for ; Fri, 24 Jul 2020 03:02:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="Fsw/pl4E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10AD420737 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:60328 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jynyj-0005os-A2 for patchwork-qemu-devel@patchwork.kernel.org; Thu, 23 Jul 2020 23:02:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55498) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jynuR-0007R5-Hg; Thu, 23 Jul 2020 22:58:07 -0400 Received: from ozlabs.org ([203.11.71.1]:35611) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jynuO-00061q-RK; Thu, 23 Jul 2020 22:58:07 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4BCYlw2CWGz9sTR; Fri, 24 Jul 2020 12:57:48 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1595559468; bh=S0SoxbGMoHrm4nxccN2FECIGesfK+qvLP0XWEh7c1/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fsw/pl4ETCgZRnUMnWoMvWLxPNqj0W0aX0j5oGnZxcSxibV0Nu6T7QHmXii5ZyiXd gwcHi8Gw1/rAeCHONaMwMfFat3Kj/nmQxVEVXbnIC3hWgbdO8VZRrKsxwbkkzFOO7K fD6aaWybXL1omHTDqn5vbbG9IPhzpY7SOwrln0IM= From: David Gibson To: dgilbert@redhat.com, frankja@linux.ibm.com, pair@us.ibm.com, qemu-devel@nongnu.org, pbonzini@redhat.com, brijesh.singh@amd.com Subject: [for-5.2 v4 09/10] host trust limitation: Alter virtio default properties for protected guests Date: Fri, 24 Jul 2020 12:57:43 +1000 Message-Id: <20200724025744.69644-10-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200724025744.69644-1-david@gibson.dropbear.id.au> References: <20200724025744.69644-1-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-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/23 22:57:48 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -9 X-Spam_score: -1.0 X-Spam_bar: - X-Spam_report: (-1.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=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: Thomas Huth , Cornelia Huck , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , ehabkost@redhat.com, kvm@vger.kernel.org, "Michael S. Tsirkin" , David Hildenbrand , mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, Christian Borntraeger , qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, Richard Henderson , David Gibson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.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 host trust limitation 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: Halil Pasic --- hw/core/machine.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index b599b0ba65..2a723bf07b 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/host-trust-limitation.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_0[] = { { "virtio-balloon-device", "page-poison", "false" }, @@ -1161,6 +1163,15 @@ 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 disabling legacy virtio support + * for virtio pci devices + */ + object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy", "on"); + object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform", "on"); } machine_class->init(machine);