From: Tianyu Lan <tiala@microsoft.com>

Secure AVIC is a new hardware feature in the AMD64
architecture to allow SEV-SNP guests to prevent the
hypervisor from generating unexpected interrupts to
a vCPU or otherwise violate architectural assumptions
around APIC behavior.

Each vCPU has a guest-allocated APIC backing page of
size 4K, which maintains APIC state for that vCPU.
APIC backing page's ALLOWED_IRR field indicates the
interrupt vectors which the guest allows the hypervisor
to send.

This patchset is to enable the feature for Hyper-V
platform. Patch "Expose x2apic_savic_update_vector()"
is to expose new fucntion and device driver and arch
code may update AVIC backing page ALLOWED_IRR field to
allow Hyper-V inject associated vector.

This patchset is based on the AMD patchset "AMD: Add
Secure AVIC Guest Support"
https://lkml.org/lkml/2025/4/17/585

Tianyu Lan (6):
  x86/Hyper-V: Not use hv apic driver when Secure AVIC is available
  x86/x2apic-savic: Expose x2apic_savic_update_vector()
  drivers/hv: Allow vmbus message synic interrupt injected from Hyper-V
  x86/Hyper-V: Allow Hyper-V to inject Hyper-V vectors
  x86/Hyper-V: Not use auto-eoi when Secure AVIC is available
  x86/x2apic-savic: Not set APIC backing page if Secure AVIC is not
    enabled.

 arch/x86/hyperv/hv_apic.c           |  3 +++
 arch/x86/hyperv/hv_init.c           | 12 ++++++++++++
 arch/x86/include/asm/apic.h         |  9 +++++++++
 arch/x86/kernel/apic/x2apic_savic.c | 13 ++++++++++++-
 arch/x86/kernel/cpu/mshyperv.c      |  3 +++
 drivers/hv/hv.c                     |  2 ++
 6 files changed, 41 insertions(+), 1 deletion(-)

-- 
2.25.1