From mboxrd@z Thu Jan 1 00:00:00 1970 From: 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> References: <1422864424-19411-1-git-send-email-feng.wu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1422864424-19411-1-git-send-email-feng.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, jiang.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.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 | 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