Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752004AbaLCHto (ORCPT ); Wed, 3 Dec 2014 02:49:44 -0500 Received: from mga11.intel.com ([192.55.52.93]:60624 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751923AbaLCHtm (ORCPT ); Wed, 3 Dec 2014 02:49:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,506,1413270000"; d="scan'208";a="631852195" From: Feng Wu To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, gleb@kernel.org, pbonzini@redhat.com, dwmw2@infradead.org, joro@8bytes.org, alex.williamson@redhat.com, jiang.liu@linux.intel.com Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, Feng Wu Subject: [v2 01/25] genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPU Date: Wed, 3 Dec 2014 15:39:30 +0800 Message-Id: <1417592394-24343-2-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1417592394-24343-1-git-send-email-feng.wu@intel.com> References: <1417592394-24343-1-git-send-email-feng.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiang Liu With Posted-Interrupts support in Intel CPU and IOMMU, an external interrupt from assigned-devices could be directly delivered to a virtual CPU in a virtual machine. Instead of hacking KVM and Intel IOMMU drivers, we propose a platform independent interface to target an interrupt to a specific virtual CPU in a virtual machine, or set virtual CPU affinity for an interrupt. By adopting this new interface and the hierarchy irqdomain, we could easily support posted-interrupts on Intel platforms, and also provide flexible enough interfaces for other platforms to support similar features. We may also cooperate between set_affinity() and set_vcpu_affinity() in IRQ core or irq chip drivers. Here is the usage scenario for this interface: Guest update MSI/MSI-X interrupt configuration -->QEMU and KVM handle this -->KVM call this interface (passing posted interrupts descriptor and guest vector) -->irq core will transfer the control to IOMMU -->IOMMU will do the real work of updating IRTE (IRTE has new format for VT-d Posted-Interrupts) Signed-off-by: Jiang Liu Signed-off-by: Feng Wu --- include/linux/irq.h | 4 ++++ kernel/irq/chip.c | 14 ++++++++++++++ kernel/irq/manage.c | 20 ++++++++++++++++++++ 3 files changed, 38 insertions(+), 0 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index f26e736..83abafc 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -324,6 +324,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * irq_request_resources * @irq_compose_msi_msg: optional to compose message content for MSI * @irq_write_msi_msg: optional to write message content for MSI + * @irq_set_vcpu_affinity: optional to target a virtual CPU in a virtual + * machine * @flags: chip specific flags */ struct irq_chip { @@ -362,6 +364,7 @@ struct irq_chip { void (*irq_compose_msi_msg)(struct irq_data *data, struct msi_msg *msg); void (*irq_write_msi_msg)(struct irq_data *data, struct msi_msg *msg); + int (*irq_set_vcpu_affinity)(struct irq_data *data, void *vcpu_info); unsigned long flags; }; @@ -416,6 +419,7 @@ extern void irq_cpu_online(void); extern void irq_cpu_offline(void); extern int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *cpumask, bool force); +extern int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info); #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_PENDING_IRQ) void irq_move_irq(struct irq_data *data); diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 6f1c7a5..fe0908f 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -948,6 +948,20 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data) return -ENOSYS; } + +/** + * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt + * @data: Pointer to interrupt specific data + * @dest: The vcpu affinity information + */ +int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info) +{ + data = data->parent_data; + if (data->chip->irq_set_vcpu_affinity) + return data->chip->irq_set_vcpu_affinity(data, vcpu_info); + + return -ENOSYS; +} #endif /** diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 8069237..bd3a1ba 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -247,6 +247,26 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) } EXPORT_SYMBOL_GPL(irq_set_affinity_hint); +int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info) +{ + struct irq_desc *desc = irq_to_desc(irq); + struct irq_chip *chip; + unsigned long flags; + int ret = -ENOSYS; + + if (!desc) + return -EINVAL; + + raw_spin_lock_irqsave(&desc->lock, flags); + chip = desc->irq_data.chip; + if (chip && chip->irq_set_vcpu_affinity) + ret = chip->irq_set_vcpu_affinity(irq_desc_get_irq_data(desc), + vcpu_info); + raw_spin_unlock_irqrestore(&desc->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity); + static void irq_affinity_notify(struct work_struct *work) { struct irq_affinity_notify *notify = -- 1.7.1 -- 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/