From: lantianyu1...@gmail.com <lantianyu1...@gmail.com> Sent: Wednesday, February 27, 2019 6:54 AM > > 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 <mikel...@microsoft.com> > Signed-off-by: Lan Tianyu <tianyu....@microsoft.com>
Reconfirming my reviewed-by after the change to fix the compile error detected by the kbuild test robot. Reviewed-by: Michael Kelley <mikel...@microsoft.com>
