From: Arnd Bergmann <arnd@xxxxxxxx> Sent: Saturday, March 8, 2025 1:05 PM > > On Fri, Mar 7, 2025, at 23:02, Roman Kisel wrote: > > @@ -5,18 +5,20 @@ menu "Microsoft Hyper-V guest support" > > config HYPERV > > tristate "Microsoft Hyper-V client drivers" > > depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \ > > - || (ACPI && ARM64 && !CPU_BIG_ENDIAN) > > + || (ARM64 && !CPU_BIG_ENDIAN) > > + depends on (ACPI || HYPERV_VTL_MODE) > > select PARAVIRT > > select X86_HV_CALLBACK_VECTOR if X86 > > - select OF_EARLY_FLATTREE if OF > > help > > Select this option to run Linux as a Hyper-V client operating > > system. > > > > config HYPERV_VTL_MODE > > bool "Enable Linux to boot in VTL context" > > - depends on X86_64 && HYPERV > > + depends on (X86_64 || ARM64) > > depends on SMP > > + select OF_EARLY_FLATTREE > > + select OF > > default n > > help > > Having the dependency below the top-level Kconfig entry feels a little > counterintuitive. You could flip that back as it was before by doing > > select HYPERV_VTL_MODE if !ACPI > depends on ACPI || SMP > > in the HYPERV option, leaving the dependency on HYPERV in > HYPERV_VTL_MODE. I would argue that we don't ever want to implicitly select HYPERV_VTL_MODE because of some other config setting or lack thereof. VTL mode is enough of a special case that it should only be explicitly selected. If someone omits ACPI, then HYPERV should not be selectable unless HYPERV_VTL_MODE is explicitly selected. The last line of the comment for HYPERV_VTL_MODE says "A kernel built with this option must run at VTL2, and will not run as a normal guest." In other words, don't choose this unless you 100% know that VTL2 is what you want. Michael > > Is OF_EARLY_FLATTREE actually needed on x86? > > Arnd
