From patchwork Tue Jul 19 13:11:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 9237357 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E8EA660574 for ; Tue, 19 Jul 2016 13:22:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D8EE026C2F for ; Tue, 19 Jul 2016 13:22:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CDA2326E64; Tue, 19 Jul 2016 13:22:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6EF4226C2F for ; Tue, 19 Jul 2016 13:22:00 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bPUwj-0002N7-P0; Tue, 19 Jul 2016 13:20:25 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bPUp9-0001EE-4b for linux-arm-kernel@lists.infradead.org; Tue, 19 Jul 2016 13:12:49 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7DAB17F402; Tue, 19 Jul 2016 13:12:16 +0000 (UTC) Received: from localhost.redhat.com (vpn1-4-201.ams2.redhat.com [10.36.4.201]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u6JDBbhM032501; Tue, 19 Jul 2016 09:12:11 -0400 From: Eric Auger To: eric.auger@redhat.com, eric.auger.pro@gmail.com, marc.zyngier@arm.com, christoffer.dall@linaro.org, andre.przywara@arm.com, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org Subject: [PATCH v11 6/8] vfio/type1: check doorbell safety Date: Tue, 19 Jul 2016 13:11:32 +0000 Message-Id: <1468933894-23250-7-git-send-email-eric.auger@redhat.com> In-Reply-To: <1468933894-23250-1-git-send-email-eric.auger@redhat.com> References: <1468933894-23250-1-git-send-email-eric.auger@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 19 Jul 2016 13:12:16 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160719_061235_677171_2D276FBF X-CRM114-Status: GOOD ( 12.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: drjones@redhat.com, kvm@vger.kernel.org, Jean-Philippe.Brucker@arm.com, Manish.Jaggi@caviumnetworks.com, p.fedin@samsung.com, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, iommu@lists.linux-foundation.org, pranav.sawargaonkar@gmail.com, pbonzini@redhat.com, kvmarm@lists.cs.columbia.edu, robert.richter@caviumnetworks.com, yehuday@marvell.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On x86 IRQ remapping is abstracted by the IOMMU. On ARM this is abstracted by the msi controller. Since we currently have no way to detect whether the MSI controller is upstream or downstream to the IOMMU we rely on the MSI doorbell information registered by the interrupt controllers. In case at least one doorbell does not implement proper isolation, we state the assignment is unsafe with regard to interrupts. This is a coase assessment but should allow to wait for a better system description. At this point ARM sMMU still advertises IOMMU_CAP_INTR_REMAP. This is removed in next patch. Signed-off-by: Eric Auger --- v9 -> v10: - coarse safety assessment based on MSI doorbell info v3 -> v4: - rename vfio_msi_parent_irq_remapping_capable into vfio_safe_irq_domain and irq_remapping into safe_irq_domains v2 -> v3: - protect vfio_msi_parent_irq_remapping_capable with CONFIG_GENERIC_MSI_IRQ_DOMAIN --- drivers/vfio/vfio_iommu_type1.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 14dc9ef..7daab53 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -37,6 +37,7 @@ #include #include #include +#include #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson " @@ -922,8 +923,14 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, INIT_LIST_HEAD(&domain->group_list); list_add(&group->next, &domain->group_list); + /* + * to advertise safe interrupts either the IOMMU or the MSI controllers + * must support IRQ remapping (aka. interrupt translation), property + * exposed by their registered doorbells + */ if (!allow_unsafe_interrupts && - !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) { + (!iommu_capable(bus, IOMMU_CAP_INTR_REMAP) && + !msi_doorbell_safe())) { pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n", __func__); ret = -EPERM;