Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754932AbbH0PR1 (ORCPT ); Thu, 27 Aug 2015 11:17:27 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45726 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753252AbbH0PRY (ORCPT ); Thu, 27 Aug 2015 11:17:24 -0400 Date: Thu, 27 Aug 2015 08:16:47 -0700 From: tip-bot for Marc Zyngier Message-ID: Cc: eric.auger@linaro.org, jiang.liu@linux.intel.com, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de, christoffer.dall@linaro.org, marc.zyngier@arm.com Reply-To: jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org, jiang.liu@linux.intel.com, eric.auger@linaro.org, marc.zyngier@arm.com, tglx@linutronix.de, christoffer.dall@linaro.org, linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org In-Reply-To: <1440604845-28229-5-git-send-email-marc.zyngier@arm.com> References: <1440604845-28229-5-git-send-email-marc.zyngier@arm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:irq/core] irqchip/GIC: Don' t deactivate interrupts forwarded to a guest Git-Commit-ID: 01f779f4862b53810ba4eb247f57bd1ad31d1c18 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4275 Lines: 130 Commit-ID: 01f779f4862b53810ba4eb247f57bd1ad31d1c18 Gitweb: http://git.kernel.org/tip/01f779f4862b53810ba4eb247f57bd1ad31d1c18 Author: Marc Zyngier AuthorDate: Wed, 26 Aug 2015 17:00:45 +0100 Committer: Thomas Gleixner CommitDate: Thu, 27 Aug 2015 17:13:49 +0200 irqchip/GIC: Don't deactivate interrupts forwarded to a guest Commit 0a4377de3056 ("genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPU") added just what we needed at the lowest level to allow an interrupt to be deactivated by a guest. When such a request reaches the GIC, it knows it doesn't need to perform the deactivation anymore, and can safely leave the guest do its magic. This of course requires additional support in both VFIO and KVM. Signed-off-by: Marc Zyngier Reviewed-and-tested-by: Eric Auger Cc: Christoffer Dall Cc: Jiang Liu Cc: Cc: kvmarm@lists.cs.columbia.edu Cc: Jason Cooper Link: http://lkml.kernel.org/r/1440604845-28229-5-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- drivers/irqchip/irq-gic.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index c835f4c..72bf81b 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -140,6 +140,36 @@ static inline unsigned int gic_irq(struct irq_data *d) return d->hwirq; } +static inline bool cascading_gic_irq(struct irq_data *d) +{ + void *data = irq_data_get_irq_handler_data(d); + + /* + * If handler_data pointing to one of the secondary GICs, then + * this is a cascading interrupt, and it cannot possibly be + * forwarded. + */ + if (data >= (void *)(gic_data + 1) && + data < (void *)(gic_data + MAX_GIC_NR)) + return true; + + return false; +} + +static inline bool forwarded_irq(struct irq_data *d) +{ + /* + * A forwarded interrupt: + * - is on the primary GIC + * - has its handler_data set to a value + * - that isn't a secondary GIC + */ + if (d->handler_data && !cascading_gic_irq(d)) + return true; + + return false; +} + /* * Routines to acknowledge, disable and enable interrupts */ @@ -163,6 +193,16 @@ static void gic_mask_irq(struct irq_data *d) static void gic_eoimode1_mask_irq(struct irq_data *d) { gic_mask_irq(d); + /* + * When masking a forwarded interrupt, make sure it is + * deactivated as well. + * + * This ensures that an interrupt that is getting + * disabled/masked will not get "stuck", because there is + * noone to deactivate it (guest is being terminated). + */ + if (forwarded_irq(d)) + gic_poke_irq(d, GIC_DIST_ACTIVE_CLEAR); } static void gic_unmask_irq(struct irq_data *d) @@ -177,6 +217,10 @@ static void gic_eoi_irq(struct irq_data *d) static void gic_eoimode1_eoi_irq(struct irq_data *d) { + /* Do not deactivate an IRQ forwarded to a vcpu. */ + if (forwarded_irq(d)) + return; + writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_DEACTIVATE); } @@ -246,6 +290,16 @@ static int gic_set_type(struct irq_data *d, unsigned int type) return gic_configure_irq(gicirq, type, base, NULL); } +static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu) +{ + /* Only interrupts on the primary GIC can be forwarded to a vcpu. */ + if (cascading_gic_irq(d)) + return -EINVAL; + + d->handler_data = vcpu; + return 0; +} + #ifdef CONFIG_SMP static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, bool force) @@ -357,6 +411,7 @@ static struct irq_chip gic_eoimode1_chip = { #endif .irq_get_irqchip_state = gic_irq_get_irqchip_state, .irq_set_irqchip_state = gic_irq_set_irqchip_state, + .irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity, .flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/