From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx> On the bare metal, enabling X2APIC mode requires interrupt remapping function which helps to deliver irq to cpu with 32-bit APIC ID. Hyper-V doesn't provide interrupt remapping function so far and Hyper-V MSI protocol already supports to deliver interrupt to the CPU whose virtual processor index is more than 255. IO-APIC interrupt still has 8-bit APIC ID limitation. This patchset is to add Hyper-V stub IOMMU driver in order to enable X2APIC mode successfully in Hyper-V Linux guest. The driver returns X2APIC interrupt remapping capability when X2APIC mode is available. X2APIC destination mode is set to physical by PATCH 1 when X2APIC is available. Hyper-V IOMMU driver will scan cpu 0~255 and set cpu into IO-APIC MAX cpu affinity cpumask if its APIC ID is 8-bit. Driver creates a Hyper-V irq domain to limit IO-APIC interrupts' affinity and make sure cpus assigned with IO-APIC interrupt are in the scope of IO-APIC MAX cpu affinity. Lan Tianyu (3): x86/Hyper-V: Set x2apic destination mode to physical when x2apic is available HYPERV/IOMMU: Add Hyper-V stub IOMMU driver MAINTAINERS: Add Hyper-V IOMMU driver into Hyper-V CORE AND DRIVERS scope MAINTAINERS | 1 + arch/x86/kernel/cpu/mshyperv.c | 10 +++ drivers/iommu/Kconfig | 8 ++ drivers/iommu/Makefile | 1 + drivers/iommu/hyperv-iommu.c | 194 +++++++++++++++++++++++++++++++++++++++++ drivers/iommu/irq_remapping.c | 3 + drivers/iommu/irq_remapping.h | 1 + 7 files changed, 218 insertions(+) create mode 100644 drivers/iommu/hyperv-iommu.c -- 2.7.4 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel