From patchwork Mon Jan 9 13:46:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 9504859 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 6956D60757 for ; Mon, 9 Jan 2017 14:06:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 57F021FE6A for ; Mon, 9 Jan 2017 14:06:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CC16284E4; Mon, 9 Jan 2017 14:06:24 +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 AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E605F1FE6A for ; Mon, 9 Jan 2017 14:06:23 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cQaaa-0005FS-V0; Mon, 09 Jan 2017 14:06:20 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cQaZl-0002sB-Vj for linux-arm-kernel@bombadil.infradead.org; Mon, 09 Jan 2017 14:05:31 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by casper.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cQaIe-0002iU-La for linux-arm-kernel@lists.infradead.org; Mon, 09 Jan 2017 13:47:51 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (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 58DC8C057FA9; Mon, 9 Jan 2017 13:47:32 +0000 (UTC) Received: from localhost.redhat.com (vpn1-6-91.ams2.redhat.com [10.36.6.91]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v09DkC5t032390; Mon, 9 Jan 2017 08:47:27 -0500 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 v7 15/19] irqdomain: irq_domain_check_msi_remap Date: Mon, 9 Jan 2017 13:46:06 +0000 Message-Id: <1483969570-3154-16-git-send-email-eric.auger@redhat.com> In-Reply-To: <1483969570-3154-1-git-send-email-eric.auger@redhat.com> References: <1483969570-3154-1-git-send-email-eric.auger@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 09 Jan 2017 13:47:32 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170109_134748_991697_93CDB0B1 X-CRM114-Status: GOOD ( 13.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: drjones@redhat.com, kvm@vger.kernel.org, punit.agrawal@arm.com, linux-kernel@vger.kernel.org, geethasowjanya.akula@gmail.com, diana.craciun@nxp.com, iommu@lists.linux-foundation.org, pranav.sawargaonkar@gmail.com, bharat.bhushan@nxp.com, shankerd@codeaurora.org, gpkulkarni@gmail.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 This new function checks whether all MSI irq domains implement IRQ remapping. This is useful to understand whether VFIO passthrough is safe with respect to interrupts. On ARM typically an MSI controller can sit downstream to the IOMMU without preventing VFIO passthrough. As such any assigned device can write into the MSI doorbell. In case the MSI controller implements IRQ remapping, assigned devices will not be able to trigger interrupts towards the host. On the contrary, the assignment must be emphasized as unsafe with respect to interrupts. Signed-off-by: Eric Auger --- v5 -> v6: - use irq_domain_hierarchical_is_msi_remap() - comment rewording v4 -> v5: - Handle DOMAIN_BUS_FSL_MC_MSI domains - Check parents --- include/linux/irqdomain.h | 1 + kernel/irq/irqdomain.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index bc2f571..188eced 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -222,6 +222,7 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node, void *host_data); extern struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec, enum irq_domain_bus_token bus_token); +extern bool irq_domain_check_msi_remap(void); extern void irq_set_default_host(struct irq_domain *host); extern int irq_domain_alloc_descs(int virq, unsigned int nr_irqs, irq_hw_number_t hwirq, int node, diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 101ee8f..fff30cb 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -278,6 +278,29 @@ struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec, EXPORT_SYMBOL_GPL(irq_find_matching_fwspec); /** + * irq_domain_check_msi_remap - Check whether all MSI + * irq domains implement IRQ remapping + */ +bool irq_domain_check_msi_remap(void) +{ + struct irq_domain *h; + bool ret = true; + + mutex_lock(&irq_domain_mutex); + list_for_each_entry(h, &irq_domain_list, link) { + if (irq_domain_is_msi(h) && + !irq_domain_hierarchical_is_msi_remap(h)) { + ret = false; + goto out; + } + } +out: + mutex_unlock(&irq_domain_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(irq_domain_check_msi_remap); + +/** * irq_set_default_host() - Set a "default" irq domain * @domain: default domain pointer *