Path: csiph.com!aioe.org!bofh.it!news.nic.it!robomod From: "Wu, Feng" Newsgroups: linux.kernel Subject: RE: [v8 3/9] iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip Date: Wed, 03 Jun 2015 03:10:02 +0200 Message-ID: References: X-Original-To: Thomas Gleixner X-Extloop1: 1 X-Ironport-Av: E=Sophos;i="5.13,543,1427785200"; d="scan'208";a="739813325" Thread-Topic: [v8 3/9] iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip Thread-Index: AQHQnTxSKZL2JvVadEGdlc0zvUy9852Z90Dg Accept-Language: en-US Content-Language: en-US X-Originating-IP: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 54 Organization: linux.* mail to news gateway X-Original-Cc: "joro@8bytes.org" , "dwmw2@infradead.org" , "jiang.liu@linux.intel.com" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "Wu, Feng" X-Original-Date: Wed, 3 Jun 2015 01:05:24 +0000 X-Original-Message-ID: X-Original-References: <1432699544-17444-1-git-send-email-feng.wu@intel.com> <1432699544-17444-4-git-send-email-feng.wu@intel.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: aioe.org linux.kernel:1157011 > -----Original Message----- > From: Thomas Gleixner [mailto:tglx@linutronix.de] > Sent: Tuesday, June 02, 2015 9:59 PM > To: Wu, Feng > Cc: joro@8bytes.org; dwmw2@infradead.org; jiang.liu@linux.intel.com; > iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org > Subject: Re: [v8 3/9] iommu, x86: Implement irq_set_vcpu_affinity for > intel_ir_chip > > On Wed, 27 May 2015, Feng Wu wrote: > > + /* stop posting interrupts, back to remapping mode */ > > + if (!vcpu_info) { > > + modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry); > > + } else { > > + vcpu_pi_info = (struct vcpu_data *)vcpu_info; > > + > > + /* > > + * "ir_data->irte_entry" saves the remapped format of IRTE, > > + * which being a cached irte is still updated when setting > > + * the affinity even when we are in posted mode. So this make > > s/make/makes/ > > > + * it possible to switch back to remapped mode from posted mode, > > + * we can just set "ir_data->irte_entry" to hardware for that > > + * purpose. Here we store the posted format of IRTE in another > > + * new member "ir_data->irte_pi_entry" to not corrupt > > Remove the 'another new member' please. That member is not longer new > once that patch is applied. > > Now there is another question. Are we actually using that pi_entry > cached value for anything else than this code here? If not, we can do > this on the stack and avoid the extra storage in ir_data. > That's a good comments. I also thought about this before. Right now the cached value is only used here in this function, but I am not sure whether we need it in future. Anyway, I think we can delete it now. Thanks, Feng > Thanks, > > tglx -- 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/