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 <feng...@intel.com>
Reviewed-by: Jiang Liu <jiang....@linux.intel.com>
Acked-by: David Woodhouse <david.woodho...@intel.com>
---
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 741896e..cb54c0a 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -980,6 +980,7 @@ 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;
@@ -994,7 +995,10 @@ 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
--
2.1.0
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