From: Lan Tianyu <tianyu....@microsoft.com>
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 | 14 +++
drivers/iommu/Kconfig | 7 ++
drivers/iommu/Makefile | 1 +
drivers/iommu/hyperv-iommu.c | 189 +++++++++++++++++++++++++++++++++++++++++
drivers/iommu/irq_remapping.c | 3 +
drivers/iommu/irq_remapping.h | 1 +
7 files changed, 216 insertions(+)
create mode 100644 drivers/iommu/hyperv-iommu.c
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2.7.4
