IRQ_POSTING_CAP
enable_posted_msi && irq_remapping_cap(IRQ_POSTING_CAP);
irq_remapping_cap(IRQ_POSTING_CAP);
amd_iommu_irq_ops.capability |= (1 << IRQ_POSTING_CAP);
amd_iommu_irq_ops.capability &= ~(1 << IRQ_POSTING_CAP);
intel_irq_remap_ops.capability &= ~(1 << IRQ_POSTING_CAP);
if (irq_remapping_cap(IRQ_POSTING_CAP) &&
intel_irq_remap_ops.capability |= 1 << IRQ_POSTING_CAP;
~(1 << IRQ_POSTING_CAP);