Fix bugs where using posted MSIs will clobber IRTEs that are configured to
post IRQs to a vCPU, and where undoing vCPU posting fails to put the IRTE
backing into posted MSI mode.
Sean Christopherson (2):
iommu/vt-d: Put IRTE back into posted MSI mode if vCPU posting is
disabled
iommu/vt-d: Don't clobber posted vCPU IRTE when host IRQ affinity
changes