Re: [PATCH 2/2] x86 Kconfig: move guest-side options under "Virtualization"

[Paolo Bonzini <pbonzini@redhat.com>]

Il 14/01/2014 01:11, Dave Hansen ha scritto:
> We now have two groups of options in "Virtualization": one for
> host-side support and a matching one for guest-side stuff.  We do
> not need separate submenus for this stuff since there are so few
> options.
> 
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Dmitry Torokhov <dtor@vmware.com>
> Cc: K. Y. Srinivasan <kys@microsoft.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Alexander Graf <agraf@suse.de>
> Cc: Gleb Natapov <gleb@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> ---
> 
>  linux.git-davehans/arch/x86/Kconfig        |   83 ----------------------------
>  linux.git-davehans/arch/x86/Kconfig.virt   |   85 +++++++++++++++++++++++++++++
>  linux.git-davehans/arch/x86/kvm/Kconfig    |    2 
>  linux.git-davehans/arch/x86/lguest/Kconfig |    1 
>  4 files changed, 85 insertions(+), 86 deletions(-)
> 
> diff -puN arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really arch/x86/Kconfig
> --- linux.git/arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really	2014-01-13 16:10:05.721497873 -0800
> +++ linux.git-davehans/arch/x86/Kconfig	2014-01-13 16:10:05.758499543 -0800
> @@ -1018,89 +1018,6 @@ config X86_ES7000
>  	  Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
>  	  supposed to run on an IA32-based Unisys ES7000 system.
>  
> -menuconfig HYPERVISOR_GUEST
> -	bool "Linux guest support"
> -	---help---
> -	  Say Y here to enable options for running Linux under various hyper-
> -	  visors. This option enables basic hypervisor detection and platform
> -	  setup.
> -
> -	  If you say N, all options in this submenu will be skipped and
> -	  disabled, and Linux guest support won't be built in.
> -
> -if HYPERVISOR_GUEST
> -
> -config PARAVIRT
> -	bool "Enable paravirtualization code"
> -	---help---
> -	  This changes the kernel so it can modify itself when it is run
> -	  under a hypervisor, potentially improving performance significantly
> -	  over full virtualization.  However, when run without a hypervisor
> -	  the kernel is theoretically slower and slightly larger.
> -
> -config PARAVIRT_DEBUG
> -	bool "paravirt-ops debugging"
> -	depends on PARAVIRT && DEBUG_KERNEL
> -	---help---
> -	  Enable to debug paravirt_ops internals.  Specifically, BUG if
> -	  a paravirt_op is missing when it is called.
> -
> -config PARAVIRT_SPINLOCKS
> -	bool "Paravirtualization layer for spinlocks"
> -	depends on PARAVIRT && SMP
> -	select UNINLINE_SPIN_UNLOCK
> -	---help---
> -	  Paravirtualized spinlocks allow a pvops backend to replace the
> -	  spinlock implementation with something virtualization-friendly
> -	  (for example, block the virtual CPU rather than spinning).
> -
> -	  It has a minimal impact on native kernels and gives a nice performance
> -	  benefit on paravirtualized KVM / Xen kernels.
> -
> -	  If you are unsure how to answer this question, answer Y.
> -
> -source "arch/x86/xen/Kconfig"
> -
> -config KVM_GUEST
> -	bool "KVM Guest support (including kvmclock)"
> -	depends on PARAVIRT
> -	select PARAVIRT_CLOCK
> -	default y
> -	---help---
> -	  This option enables various optimizations for running under the KVM
> -	  hypervisor. It includes a paravirtualized clock, so that instead
> -	  of relying on a PIT (or probably other) emulation by the
> -	  underlying device model, the host provides the guest with
> -	  timing infrastructure such as time of day, and system time
> -
> -config KVM_DEBUG_FS
> -	bool "Enable debug information for KVM Guests in debugfs"
> -	depends on KVM_GUEST && DEBUG_FS
> -	default n
> -	---help---
> -	  This option enables collection of various statistics for KVM guest.
> -	  Statistics are displayed in debugfs filesystem. Enabling this option
> -	  may incur significant overhead.
> -
> -source "arch/x86/lguest/Kconfig"
> -
> -config PARAVIRT_TIME_ACCOUNTING
> -	bool "Paravirtual steal time accounting"
> -	depends on PARAVIRT
> -	default n
> -	---help---
> -	  Select this option to enable fine granularity task steal time
> -	  accounting. Time spent executing other tasks in parallel with
> -	  the current vCPU is discounted from the vCPU power. To account for
> -	  that, there can be a small performance impact.
> -
> -	  If in doubt, say N here.
> -
> -config PARAVIRT_CLOCK
> -	bool
> -
> -endif #HYPERVISOR_GUEST
> -
>  config NO_BOOTMEM
>  	def_bool y
>  
> diff -puN arch/x86/Kconfig.virt~x86-Kconfig-move-paravirt-under-virtualization-really arch/x86/Kconfig.virt
> --- linux.git/arch/x86/Kconfig.virt~x86-Kconfig-move-paravirt-under-virtualization-really	2014-01-13 16:10:05.722497918 -0800
> +++ linux.git-davehans/arch/x86/Kconfig.virt	2014-01-13 16:10:35.730852434 -0800
> @@ -1,3 +1,5 @@
> +# No menu items in here, just common config variables:
> +source "virt/kvm/Kconfig"
>  
>  menu "Virtualization"
>  
> @@ -22,4 +24,87 @@ source drivers/lguest/Kconfig
>  
>  endif # HYPERVISOR_HOST
>  
> +config HYPERVISOR_GUEST
> +	bool "Guest-Side Features (Linux running under a Hypervisor)"
> +	---help---
> +	  Say Y here to enable options for running Linux under various hyper-
> +	  visors. This option enables basic hypervisor detection and platform
> +	  setup.
> +
> +	  If you say N, all options in this submenu will be skipped and
> +	  disabled, and Linux guest support won't be built in.
> +
> +if HYPERVISOR_GUEST
> +
> +config PARAVIRT
> +	bool "Enable paravirtualization code"
> +	---help---
> +	  This changes the kernel so it can modify itself when it is run
> +	  under a hypervisor, potentially improving performance significantly
> +	  over full virtualization.  However, when run without a hypervisor
> +	  the kernel is theoretically slower and slightly larger.
> +
> +config PARAVIRT_DEBUG
> +	bool "paravirt-ops debugging"
> +	depends on PARAVIRT && DEBUG_KERNEL
> +	---help---
> +	  Enable to debug paravirt_ops internals.  Specifically, BUG if
> +	  a paravirt_op is missing when it is called.
> +
> +config PARAVIRT_SPINLOCKS
> +	bool "Paravirtualization layer for spinlocks"
> +	depends on PARAVIRT && SMP
> +	select UNINLINE_SPIN_UNLOCK
> +	---help---
> +	  Paravirtualized spinlocks allow a pvops backend to replace the
> +	  spinlock implementation with something virtualization-friendly
> +	  (for example, block the virtual CPU rather than spinning).
> +
> +	  It has a minimal impact on native kernels and gives a nice performance
> +	  benefit on paravirtualized KVM / Xen kernels.
> +
> +	  If you are unsure how to answer this question, answer Y.
> +
> +source "arch/x86/xen/Kconfig"
> +
> +config KVM_GUEST
> +	bool "KVM Guest support (including kvmclock)"
> +	depends on PARAVIRT
> +	select PARAVIRT_CLOCK
> +	default y
> +	---help---
> +	  This option enables various optimizations for running under the KVM
> +	  hypervisor. It includes a paravirtualized clock, so that instead
> +	  of relying on a PIT (or probably other) emulation by the
> +	  underlying device model, the host provides the guest with
> +	  timing infrastructure such as time of day, and system time
> +
> +config KVM_DEBUG_FS
> +	bool "Enable debug information for KVM Guests in debugfs"
> +	depends on KVM_GUEST && DEBUG_FS
> +	default n
> +	---help---
> +	  This option enables collection of various statistics for KVM guest.
> +	  Statistics are displayed in debugfs filesystem. Enabling this option
> +	  may incur significant overhead.
> +
> +source "arch/x86/lguest/Kconfig"
> +
> +config PARAVIRT_TIME_ACCOUNTING
> +	bool "Paravirtual steal time accounting"
> +	depends on PARAVIRT
> +	default n
> +	---help---
> +	  Select this option to enable fine granularity task steal time
> +	  accounting. Time spent executing other tasks in parallel with
> +	  the current vCPU is discounted from the vCPU power. To account for
> +	  that, there can be a small performance impact.
> +
> +	  If in doubt, say N here.
> +
> +config PARAVIRT_CLOCK
> +	bool
> +
> +endif # HYPERVISOR_GUEST
> +
>  endmenu # "Virtualization"
> diff -puN arch/x86/lguest/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really arch/x86/lguest/Kconfig
> --- linux.git/arch/x86/lguest/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really	2014-01-13 16:10:05.724498009 -0800
> +++ linux.git-davehans/arch/x86/lguest/Kconfig	2014-01-13 16:10:05.759499589 -0800
> @@ -2,7 +2,6 @@ config LGUEST_GUEST
>  	bool "Lguest guest support"
>  	depends on X86_32 && PARAVIRT
>  	select TTY
> -	select VIRTUALIZATION
>  	select VIRTIO
>  	select VIRTIO_CONSOLE
>  	help
> diff -puN arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really arch/x86/kvm/Kconfig
> --- linux.git/arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization-really	2014-01-13 16:10:05.729498234 -0800
> +++ linux.git-davehans/arch/x86/kvm/Kconfig	2014-01-13 16:10:05.760499634 -0800
> @@ -2,8 +2,6 @@
>  # KVM configuration
>  #
>  
> -source "virt/kvm/Kconfig"
> -
>  config KVM
>  	tristate "Kernel-based Virtual Machine (KVM) support"
>  	depends on HAVE_KVM
> _
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>