From patchwork Wed Oct 12 13:22:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 9373051 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 26D2C60772 for ; Wed, 12 Oct 2016 13:30:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 146AC28B4D for ; Wed, 12 Oct 2016 13:30:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 05FFE295E7; Wed, 12 Oct 2016 13:30:40 +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=ham 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 D9FF128B4D for ; Wed, 12 Oct 2016 13:30:38 +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 1buJag-00037t-Hj; Wed, 12 Oct 2016 13:29:02 +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 1buJVi-0005zp-HD for linux-arm-kernel@lists.infradead.org; Wed, 12 Oct 2016 13:23:57 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (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 3BF7FC056792; Wed, 12 Oct 2016 13:23:38 +0000 (UTC) Received: from localhost.redhat.com (vpn1-6-235.ams2.redhat.com [10.36.6.235]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u9CDMQCs010906; Wed, 12 Oct 2016 09:23:33 -0400 From: Eric Auger To: eric.auger@redhat.com, eric.auger.pro@gmail.com, christoffer.dall@linaro.org, marc.zyngier@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 v14 14/16] vfio/type1: Check doorbell safety Date: Wed, 12 Oct 2016 13:22:22 +0000 Message-Id: <1476278544-3397-15-git-send-email-eric.auger@redhat.com> In-Reply-To: <1476278544-3397-1-git-send-email-eric.auger@redhat.com> References: <1476278544-3397-1-git-send-email-eric.auger@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 12 Oct 2016 13:23:38 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161012_062354_865136_0DB8EE28 X-CRM114-Status: GOOD ( 14.01 ) 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, 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 coarse 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 --- v13 -> v15: - check vfio_msi_resv before checking whether msi doorbell is safe 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 | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index e0c97ef..c18ba9d 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -442,6 +442,29 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) } /** + * vfio_msi_resv - Return whether any VFIO iommu domain requires + * MSI mapping + * + * @iommu: vfio iommu handle + * + * Return: true of MSI mapping is needed, false otherwise + */ +static bool vfio_msi_resv(struct vfio_iommu *iommu) +{ + struct iommu_domain_msi_resv msi_resv; + struct vfio_domain *d; + int ret; + + list_for_each_entry(d, &iommu->domain_list, next) { + ret = iommu_domain_get_attr(d->domain, DOMAIN_ATTR_MSI_RESV, + &msi_resv); + if (!ret) + return true; + } + return false; +} + +/** * vfio_set_msi_aperture - Sets the msi aperture on all domains * requesting MSI mapping * @@ -945,8 +968,13 @@ 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) + */ if (!allow_unsafe_interrupts && - !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) { + (!iommu_capable(bus, IOMMU_CAP_INTR_REMAP) && + !(vfio_msi_resv(iommu) && iommu_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;