From mboxrd@z Thu Jan 1 00:00:00 1970 From: Feng Wu Subject: [v7 4/8] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Date: Mon, 25 May 2015 13:28:50 +0800 Message-ID: <1432531734-25978-5-git-send-email-feng.wu@intel.com> References: <1432531734-25978-1-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: <1432531734-25978-1-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: joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org Cc: tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, jiang.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@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 | 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 1955b09..646f4cf 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -994,7 +994,10 @@ 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->pst != 1) + modify_irte(&ir_data->irq_2_iommu, irte); /* * After this point, all the interrupts will start arriving -- 2.1.0