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author | Lan Tianyu | 2019-02-27 15:54:04 +0100 |
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committer | Joerg Roedel | 2019-02-28 11:12:16 +0100 |
commit | 29217a4746835fef35279abbd12c1a1efe83bfca (patch) | |
tree | c5ea0066251ce2605754dd785373bb27126d68dc /kernel/umh.c | |
parent | x86/Hyper-V: Set x2apic destination mode to physical when x2apic is available (diff) | |
download | kernel-qcow2-linux-29217a4746835fef35279abbd12c1a1efe83bfca.tar.gz kernel-qcow2-linux-29217a4746835fef35279abbd12c1a1efe83bfca.tar.xz kernel-qcow2-linux-29217a4746835fef35279abbd12c1a1efe83bfca.zip |
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 'kernel/umh.c')
0 files changed, 0 insertions, 0 deletions