Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753604AbbERKWT (ORCPT ); Mon, 18 May 2015 06:22:19 -0400 Received: from mga14.intel.com ([192.55.52.115]:50910 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753035AbbERKWH (ORCPT ); Mon, 18 May 2015 06:22:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,453,1427785200"; d="scan'208";a="711804865" From: Feng Wu To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: linux-kernel@vger.kernel.org, jiang.liu@linux.intel.com, Feng Wu Subject: [v5 1/3] genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPU Date: Mon, 18 May 2015 18:13:13 +0800 Message-Id: <1431943995-3344-2-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1431943995-3344-1-git-send-email-feng.wu@intel.com> References: <1431943995-3344-1-git-send-email-feng.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4934 Lines: 134 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. 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 | 6 ++++++ kernel/irq/chip.c | 14 ++++++++++++++ kernel/irq/manage.c | 21 +++++++++++++++++++++ 3 files changed, 41 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index 62c6901..cb688fb 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -327,6 +327,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * @irq_write_msi_msg: optional to write message content for MSI * @irq_get_irqchip_state: return the internal state of an interrupt * @irq_set_irqchip_state: set the internal state of a interrupt + * @irq_set_vcpu_affinity: optional to target a vCPU in a virtual machine * @flags: chip specific flags */ struct irq_chip { @@ -369,6 +370,8 @@ struct irq_chip { int (*irq_get_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool *state); int (*irq_set_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool state); + int (*irq_set_vcpu_affinity)(struct irq_data *data, void *vcpu_info); + unsigned long flags; }; @@ -422,6 +425,7 @@ 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); @@ -467,6 +471,8 @@ extern int irq_chip_set_affinity_parent(struct irq_data *data, const struct cpumask *dest, bool force); extern int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on); +extern int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, + void *vcpu_info); #endif /* Handling of unhandled and spurious interrupts: */ diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index eb9a4ea..55016b2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -950,6 +950,20 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data) } /** + * 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; +} + +/** * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt * @data: Pointer to interrupt specific data * @on: Whether to set or reset the wake-up capability of this irq diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e68932b..7167825 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -256,6 +256,27 @@ 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) +{ + unsigned long flags; + struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); + struct irq_data *data; + struct irq_chip *chip; + int ret = -ENOSYS; + + if (!desc) + return -EINVAL; + + data = irq_desc_get_irq_data(desc); + chip = irq_data_get_irq_chip(data); + if (chip && chip->irq_set_vcpu_affinity) + ret = chip->irq_set_vcpu_affinity(data, vcpu_info); + irq_put_desc_unlock(desc, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity); + static void irq_affinity_notify(struct work_struct *work) { struct irq_affinity_notify *notify = -- 2.1.0 -- 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/