From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932424AbbFEFwi (ORCPT ); Fri, 5 Jun 2015 01:52:38 -0400 Received: from mga02.intel.com ([134.134.136.20]:33935 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932147AbbFEFwZ (ORCPT ); Fri, 5 Jun 2015 01:52:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,556,1427785200"; d="scan'208";a="705724103" From: Feng Wu To: joro@8bytes.org, dwmw2@infradead.org, tglx@linutronix.de Cc: jiang.liu@linux.intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Feng Wu Subject: [v9 5/9] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Date: Fri, 5 Jun 2015 13:42:50 +0800 Message-Id: <1433482974-14614-6-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1433482974-14614-1-git-send-email-feng.wu@intel.com> References: <1433482974-14614-1-git-send-email-feng.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 028d628..c30845a 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -1002,7 +1002,10 @@ 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); + + /* Update the hardware only if the interrupt is in remapped mode. */ + if (ir_data->irq_2_iommu.mode == IRQ_REMAPPING) + modify_irte(&ir_data->irq_2_iommu, irte); /* * After this point, all the interrupts will start arriving -- 2.1.0