diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 831613959a92..46668e255421 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -475,6 +475,12 @@ static bool __init ms_hyperv_x2apic_available(void) * (logically) generates MSIs directly to the system APIC irq domain. * There is no HPET, and PCI MSI/MSI-X interrupts are remapped by the * pci-hyperv host bridge. + * + * Note: for a Hyper-V root partition, this will always return false. + * The hypervisor doesn't expose these HYPERV_CPUID_VIRT_STACK_* cpuids by + * default, they are implemented as intercepts by the Windows Hyper-V stack. + * Even a nested root partition (L2 root) will not get them because the + * nested (L1) hypervisor filters them out. */ static bool __init ms_hyperv_msi_ext_dest_id(void) { |