From patchwork Wed Jan 4 13:32:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 9497959 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 2B63E60237 for ; Wed, 4 Jan 2017 22:26:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0D3D027BFC for ; Wed, 4 Jan 2017 22:26:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 01CA02832D; Wed, 4 Jan 2017 22:26:10 +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 A34CE27BFC for ; Wed, 4 Jan 2017 22:26:10 +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 1cOtzK-0001q6-Vg; Wed, 04 Jan 2017 22:24:54 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cOtlC-0003Q7-Ds for linux-arm-kernel@bombadil.infradead.org; Wed, 04 Jan 2017 22:10:18 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1cOlhR-0006Eh-Pb for linux-arm-kernel@lists.infradead.org; Wed, 04 Jan 2017 13:33:54 +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 215074D690; Wed, 4 Jan 2017 13:33:37 +0000 (UTC) Received: from localhost.redhat.com (vpn1-4-93.ams2.redhat.com [10.36.4.93]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v04DWS26024520; Wed, 4 Jan 2017 08:33:32 -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 v5 13/17] irqdomain: irq_domain_check_msi_remap Date: Wed, 4 Jan 2017 13:32:22 +0000 Message-Id: <1483536746-2725-14-git-send-email-eric.auger@redhat.com> In-Reply-To: <1483536746-2725-1-git-send-email-eric.auger@redhat.com> References: <1483536746-2725-1-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 [10.5.110.26]); Wed, 04 Jan 2017 13:33:37 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170104_083353_971969_4516ED1F X-CRM114-Status: GOOD ( 13.98 ) 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 platform and PCI MSI 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 --- v4 -> v5: - Handle DOMAIN_BUS_FSL_MC_MSI domains - Check parents --- include/linux/irqdomain.h | 1 + kernel/irq/irqdomain.c | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index ab017b2..281a40f 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -219,6 +219,7 @@ 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 8c0a0ae..700caea 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -278,6 +278,47 @@ struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec, EXPORT_SYMBOL_GPL(irq_find_matching_fwspec); /** + * irq_domain_is_msi_remap - Check if @domain or any parent + * has MSI remapping support + * @domain: domain pointer + */ +static bool irq_domain_is_msi_remap(struct irq_domain *domain) +{ + struct irq_domain *h = domain; + + for (; h; h = h->parent) { + if (h->flags & IRQ_DOMAIN_FLAG_MSI_REMAP) + return true; + } + return false; +} + +/** + * irq_domain_check_msi_remap() - Checks 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 (((h->bus_token & DOMAIN_BUS_PCI_MSI) || + (h->bus_token & DOMAIN_BUS_PLATFORM_MSI) || + (h->bus_token & DOMAIN_BUS_FSL_MC_MSI)) && + !irq_domain_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 *