[PATCH v3 0/3] Nested virtualization fixes for root partition

[Wei Liu]

On Fri, Jul 11, 2025 at 12:18:49PM -0700, Nuno Das Neves wrote:
> Fixes for running as nested root partition on the Microsoft Hypervisor.
> 
> The first patch changes vmbus to make hypercalls to the L0 hypervisor
> instead of the L1. This is needed because L0 hypervisor, not the L1, is
> the one hosting the Windows root partition with the VMM that provides
> vmbus.
> 
> The 2nd and 3rd patches fix interrupt unmasking on nested. In this
> scenario, the L1 (nested) hypervisor does the interrupt mapping to root
> partition cores. The vectors just need to be mapped with
> MAP_DEVICE_INTERRUPT instead of affinitized with RETARGET_INTERRUPT.
> 
> Changes in v3:
> - Remove 3 patches (#1,#3,#4 from v2) which were merged already (Wei Liu)
> - Fix bug in #1 introduced in v2 (Michael Kelley)
> - Improve commit message in #2 (Michael Kelley)
> - Document return value of hv_map_msi_interrupt() in #2 (Michael Kelley)
> 
> Changes in v2:
> - Reword commit messages for clarity (Michael Kelley, Bjorn Helgaas)
> - Open-code nested hypercalls to reduce unnecessary code (Michael Kelley)
> - Add patch (#3) to fix cpu_online_mask issue (Thomas Gleixner)
> - Add patch (#4) to fix error return values (Michael Kelley)
> - Remove several redundant error messages and checks (Michael Kelley)
> 
> Nuno Das Neves (1):
>   Drivers: hv: Use nested hypercall for post message and signal event
> 
> Stanislav Kinsburskii (2):
>   x86/hyperv: Expose hv_map_msi_interrupt()
>   PCI: hv: Use the correct hypercall for unmasking interrupts on nested
> 

Applied. Thanks.