Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933169AbbBBITk (ORCPT ); Mon, 2 Feb 2015 03:19:40 -0500 Received: from mga02.intel.com ([134.134.136.20]:43164 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933100AbbBBISR (ORCPT ); Mon, 2 Feb 2015 03:18:17 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,505,1418112000"; d="scan'208";a="679561032" From: Feng Wu To: dwmw2@infradead.org, joro@8bytes.org Cc: jiang.liu@linux.intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Feng Wu Subject: [v4 4/8] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Date: Mon, 2 Feb 2015 16:07:00 +0800 Message-Id: <1422864424-19411-5-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1422864424-19411-1-git-send-email-feng.wu@intel.com> References: <1422864424-19411-1-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: 1882 Lines: 48 We don't need to migrate the irqs for VT-d Posted-Interrupts here. When 'pst' is set in IRTE, the associated irq will be posted to guests instead of interrupt remapping. The destination of the interrupt is set in Posted-Interrupts Descriptor, and the migration happens during vCPU scheduling. However, we still update the cached irte here, which can be used when changing back to remapping mode. Signed-off-by: Feng Wu Reviewed-by: Jiang Liu Acked-by: David Woodhouse --- drivers/iommu/intel_irq_remapping.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 48c2051..ab9057a 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -977,6 +977,7 @@ intel_ir_set_affinity(struct irq_data *data, const struct cpumask *mask, { struct intel_ir_data *ir_data = data->chip_data; struct irte *irte = &ir_data->irte_entry; + struct irte_pi *irte_pi = (struct irte_pi *)irte; struct irq_cfg *cfg = irqd_cfg(data); struct irq_data *parent = data->parent_data; int ret; @@ -991,7 +992,10 @@ intel_ir_set_affinity(struct irq_data *data, const struct cpumask *mask, */ irte->vector = cfg->vector; irte->dest_id = IRTE_DEST(cfg->dest_apicid); - modify_irte(&ir_data->irq_2_iommu, irte); + + /* We don't need to modify irte if the interrupt is for posting. */ + if (irte_pi->pst != 1) + modify_irte(&ir_data->irq_2_iommu, irte); /* * After this point, all the interrupts will start arriving -- 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/