From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751709AbaLROdF (ORCPT ); Thu, 18 Dec 2014 09:33:05 -0500 Received: from mga11.intel.com ([192.55.52.93]:3146 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbaLROdC convert rfc822-to-8bit (ORCPT ); Thu, 18 Dec 2014 09:33:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="430748863" From: "Zhang, Yang Z" To: "Wu, Feng" , "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: "eric.auger@linaro.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "Wu, Feng" Subject: RE: [v3 06/26] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Thread-Topic: [v3 06/26] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Thread-Index: AQHQFiFw/2wcwNXVUk6mLzPIG8E78JyVcJsw Date: Thu, 18 Dec 2014 14:26:24 +0000 Message-ID: References: <1418397300-10870-1-git-send-email-feng.wu@intel.com> <1418397300-10870-7-git-send-email-feng.wu@intel.com> In-Reply-To: <1418397300-10870-7-git-send-email-feng.wu@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Feng Wu wrote on 2014-12-12: > 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 > --- > drivers/iommu/intel_irq_remapping.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > 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); What happens if user changes the IRQ affinity manually? > > /* > * After this point, all the interrupts will start arriving Best regards, Yang