Re: [PATCH 2/2] x86: make hyperv support optional

[Wei Liu <wei.liu@kernel.org>]

On Tue, Nov 17, 2020 at 09:23:08PM +0100, Enrico Weigelt, metux IT consult wrote:
> Make it possible to opt-out from hyperv support.
> 

"Hyper-V support".

Have you tested this patch? If so, how?

> Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
> ---
>  arch/x86/Kconfig                 | 7 +++++++
>  arch/x86/kernel/cpu/Makefile     | 4 ++--
>  arch/x86/kernel/cpu/hypervisor.c | 2 ++
>  drivers/hv/Kconfig               | 2 +-
>  4 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index c227c1fa0091..60aab344d6ab 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -808,6 +808,13 @@ config VMWARE_GUEST
>  	  This option enables several optimizations for running under the
>  	  VMware hypervisor.
>  
> +config HYPERV_GUEST
> +	bool "HyperV Guest support"

Hyper-V here.

> +	default y
> +	help
> +	  This option enables several optimizations for running under the
> +	  HyperV hypervisor.
> +

"for running under Hyper-V".

>  config KVM_GUEST
>  	bool "KVM Guest support (including kvmclock)"
>  	depends on PARAVIRT
> diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> index a615b0152bf0..5536b801cb44 100644
> --- a/arch/x86/kernel/cpu/Makefile
> +++ b/arch/x86/kernel/cpu/Makefile
> @@ -51,9 +51,9 @@ obj-$(CONFIG_X86_CPU_RESCTRL)		+= resctrl/
>  
>  obj-$(CONFIG_X86_LOCAL_APIC)		+= perfctr-watchdog.o
>  
> -obj-$(CONFIG_HYPERVISOR_GUEST)		+= hypervisor.o mshyperv.o
> +obj-$(CONFIG_HYPERVISOR_GUEST)		+= hypervisor.o
>  obj-$(CONFIG_VMWARE_GUEST)		+= vmware.o
> -
> +obj-$(CONFIG_HYPERV_GUEST)		+= mshyperv.o
>  obj-$(CONFIG_ACRN_GUEST)		+= acrn.o
>  
>  ifdef CONFIG_X86_FEATURE_NAMES
> diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
> index c0e770a224aa..32d6b2084d05 100644
> --- a/arch/x86/kernel/cpu/hypervisor.c
> +++ b/arch/x86/kernel/cpu/hypervisor.c
> @@ -37,7 +37,9 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
>  #ifdef CONFIG_VMWARE_GUEST
>  	&x86_hyper_vmware,
>  #endif
> +#ifdef CONFIG_HYPERV_GUEST
>  	&x86_hyper_ms_hyperv,
> +#endif
>  #ifdef CONFIG_KVM_GUEST
>  	&x86_hyper_kvm,
>  #endif
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 79e5356a737a..7b3094c59a81 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -4,7 +4,7 @@ menu "Microsoft Hyper-V guest support"
>  
>  config HYPERV
>  	tristate "Microsoft Hyper-V client drivers"
> -	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
> +	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERV_GUEST
>  	select PARAVIRT
>  	select X86_HV_CALLBACK_VECTOR
>  	help

Maybe that one should be moved to x86/Kconfig and used instead?

Wei.

> -- 
> 2.11.0
>