When the interrupt is configured in posted mode, the destination of the interrupt is set in the Posted-Interrupts Descriptor and the migration of these interrupts happens during vCPU scheduling.
We still update the cached irte, which will be used when changing back to remapping mode, but we avoid writing the table entry. Signed-off-by: Feng Wu <feng...@intel.com> Reviewed-by: Jiang Liu <jiang....@linux.intel.com> Acked-by: David Woodhouse <david.woodho...@intel.com> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Joerg Roedel <j...@8bytes.org> --- 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 68bce0a..3bcb459 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -1003,7 +1003,10 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/