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| author | Lan Tianyu <Tianyu.Lan@microsoft.com> | 2019-02-27 22:54:04 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2019-02-28 11:12:16 +0100 |
| commit | 29217a4746835fef35279abbd12c1a1efe83bfca (patch) | |
| tree | c5ea0066251ce2605754dd785373bb27126d68dc /drivers/iommu/Kconfig | |
| parent | 84fdfafab849036b5aefa52824b5cb42e887ef0e (diff) | |
| download | linux-29217a4746835fef35279abbd12c1a1efe83bfca.tar.bz2 | |
iommu/hyper-v: Add Hyper-V stub IOMMU driver
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 patch 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. Otherwise,
it creates a Hyper-V irq domain to limit IO-APIC interrupts' affinity
and make sure cpus assigned with IO-APIC interrupt have 8-bit APIC ID.
Define 24 IO-APIC remapping entries because Hyper-V only expose one
single IO-APIC and one IO-APIC has 24 pins according IO-APIC spec(
https://pdos.csail.mit.edu/6.828/2016/readings/ia32/ioapic.pdf).
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/Kconfig')
| -rw-r--r-- | drivers/iommu/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index d9a25715650e..34b066541491 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -435,4 +435,13 @@ config QCOM_IOMMU help Support for IOMMU on certain Qualcomm SoCs. +config HYPERV_IOMMU + bool "Hyper-V x2APIC IRQ Handling" + depends on HYPERV + select IOMMU_API + default HYPERV + help + Stub IOMMU driver to handle IRQs as to allow Hyper-V Linux + guests to run with x2APIC mode enabled. + endif # IOMMU_SUPPORT |