[PATCH 1/2] x86 Kconfig: create x86/Kconfig.virt

[PATCH 1/2] x86 Kconfig: create x86/Kconfig.virt

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

Right now, there is a "Enable paravirtualization code" option in
the "Processor Features" menu, which means Xen.  There is also a
group of host-side paravirtualization options specific to KVM
under the top-level "Virtualization" menu.

I think it makes a lot of sense to group the host and guest side
things together, especially since the top-level "Virtualization"
menu is so sparsely populated.

This creates a new hypervisor-independent arch/x86/Kconfig.virt
file, and moves the "Virtualization" menu to be defined in there.
Currently CONFIG_VIRTUALIZATION really means "host-side", so
create a new config option which matches the guest-side one, and
default its value to be what CONFIG_VIRTUALIZATION was set to.

This also removes the very counterintuitive references to
lguest/vhost code *from* kvm-specific code and removes the silly:

	depends on HAVE_KVM || X86

dependency.  It makes zero sense to have entries defined in
arch/x86 depend on x86.

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      |    2 +-
 linux.git-davehans/arch/x86/Kconfig.virt |   25 +++++++++++++++++++++++++
 linux.git-davehans/arch/x86/kvm/Kconfig  |   19 -------------------
 3 files changed, 26 insertions(+), 20 deletions(-)

diff -puN arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization arch/x86/Kconfig
--- linux.git/arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization	2014-01-13 16:09:29.785875796 -0800
+++ linux.git-davehans/arch/x86/Kconfig	2014-01-13 16:09:29.793876157 -0800
@@ -2416,6 +2416,6 @@ source "security/Kconfig"
 
 source "crypto/Kconfig"
 
-source "arch/x86/kvm/Kconfig"
+source "arch/x86/Kconfig.virt"
 
 source "lib/Kconfig"
diff -puN /dev/null arch/x86/Kconfig.virt
--- /dev/null	2013-11-27 17:20:18.337162396 -0800
+++ linux.git-davehans/arch/x86/Kconfig.virt	2014-01-13 16:09:29.793876157 -0800
@@ -0,0 +1,25 @@
+
+menu "Virtualization"
+
+config VIRTUALIZATION
+	bool
+
+config HYPERVISOR_HOST
+	bool "Host-Side Features (Linux as the Hypervisor)"
+	default y if VIRTUALIZATION
+	---help---
+	  Say Y here to get to see options for using your Linux host to run other
+	  operating systems inside virtual machines (guests).
+	  This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and disabled.
+
+if HYPERVISOR_HOST
+
+source arch/x86/kvm/Kconfig
+source drivers/vhost/Kconfig
+source drivers/lguest/Kconfig
+
+endif # HYPERVISOR_HOST
+
+endmenu # "Virtualization"
diff -puN arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization arch/x86/kvm/Kconfig
--- linux.git/arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization	2014-01-13 16:09:29.787875886 -0800
+++ linux.git-davehans/arch/x86/kvm/Kconfig	2014-01-13 16:09:29.793876157 -0800
@@ -4,19 +4,6 @@
 
 source "virt/kvm/Kconfig"
 
-menuconfig VIRTUALIZATION
-	bool "Virtualization"
-	depends on HAVE_KVM || X86
-	default y
-	---help---
-	  Say Y here to get to see options for using your Linux host to run other
-	  operating systems inside virtual machines (guests).
-	  This option alone does not add any kernel code.
-
-	  If you say N, all options in this submenu will be skipped and disabled.
-
-if VIRTUALIZATION
-
 config KVM
 	tristate "Kernel-based Virtual Machine (KVM) support"
 	depends on HAVE_KVM
@@ -93,9 +80,3 @@ config KVM_DEVICE_ASSIGNMENT
 
 	  If unsure, say Y.
 
-# OK, it's a little counter-intuitive to do this, but it puts it neatly under
-# the virtualization menu.
-source drivers/vhost/Kconfig
-source drivers/lguest/Kconfig
-
-endif # VIRTUALIZATION
_

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

[Dave Hansen]

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
_

Re: [PATCH 1/2] x86 Kconfig: create x86/Kconfig.virt

[Paolo Bonzini]

Il 14/01/2014 01:11, Dave Hansen ha scritto:
> From: Dave Hansen <dave.hansen@linux.intel.com>
> 
> Right now, there is a "Enable paravirtualization code" option in
> the "Processor Features" menu, which means Xen.  There is also a
> group of host-side paravirtualization options specific to KVM
> under the top-level "Virtualization" menu.
> 
> I think it makes a lot of sense to group the host and guest side
> things together, especially since the top-level "Virtualization"
> menu is so sparsely populated.
> 
> This creates a new hypervisor-independent arch/x86/Kconfig.virt
> file, and moves the "Virtualization" menu to be defined in there.
> Currently CONFIG_VIRTUALIZATION really means "host-side", so
> create a new config option which matches the guest-side one, and
> default its value to be what CONFIG_VIRTUALIZATION was set to.
> 
> This also removes the very counterintuitive references to
> lguest/vhost code *from* kvm-specific code and removes the silly:
> 
> 	depends on HAVE_KVM || X86
> 
> dependency.  It makes zero sense to have entries defined in
> arch/x86 depend on x86.
> 
> 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      |    2 +-
>  linux.git-davehans/arch/x86/Kconfig.virt |   25 +++++++++++++++++++++++++
>  linux.git-davehans/arch/x86/kvm/Kconfig  |   19 -------------------
>  3 files changed, 26 insertions(+), 20 deletions(-)
> 
> diff -puN arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization arch/x86/Kconfig
> --- linux.git/arch/x86/Kconfig~x86-Kconfig-move-paravirt-under-virtualization	2014-01-13 16:09:29.785875796 -0800
> +++ linux.git-davehans/arch/x86/Kconfig	2014-01-13 16:09:29.793876157 -0800
> @@ -2416,6 +2416,6 @@ source "security/Kconfig"
>  
>  source "crypto/Kconfig"
>  
> -source "arch/x86/kvm/Kconfig"
> +source "arch/x86/Kconfig.virt"
>  
>  source "lib/Kconfig"
> diff -puN /dev/null arch/x86/Kconfig.virt
> --- /dev/null	2013-11-27 17:20:18.337162396 -0800
> +++ linux.git-davehans/arch/x86/Kconfig.virt	2014-01-13 16:09:29.793876157 -0800
> @@ -0,0 +1,25 @@
> +
> +menu "Virtualization"
> +
> +config VIRTUALIZATION
> +	bool
> +
> +config HYPERVISOR_HOST
> +	bool "Host-Side Features (Linux as the Hypervisor)"
> +	default y if VIRTUALIZATION
> +	---help---
> +	  Say Y here to get to see options for using your Linux host to run other
> +	  operating systems inside virtual machines (guests).
> +	  This option alone does not add any kernel code.
> +
> +	  If you say N, all options in this submenu will be skipped and disabled.
> +
> +if HYPERVISOR_HOST
> +
> +source arch/x86/kvm/Kconfig
> +source drivers/vhost/Kconfig
> +source drivers/lguest/Kconfig
> +
> +endif # HYPERVISOR_HOST
> +
> +endmenu # "Virtualization"
> diff -puN arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization arch/x86/kvm/Kconfig
> --- linux.git/arch/x86/kvm/Kconfig~x86-Kconfig-move-paravirt-under-virtualization	2014-01-13 16:09:29.787875886 -0800
> +++ linux.git-davehans/arch/x86/kvm/Kconfig	2014-01-13 16:09:29.793876157 -0800
> @@ -4,19 +4,6 @@
>  
>  source "virt/kvm/Kconfig"
>  
> -menuconfig VIRTUALIZATION
> -	bool "Virtualization"
> -	depends on HAVE_KVM || X86
> -	default y
> -	---help---
> -	  Say Y here to get to see options for using your Linux host to run other
> -	  operating systems inside virtual machines (guests).
> -	  This option alone does not add any kernel code.
> -
> -	  If you say N, all options in this submenu will be skipped and disabled.
> -
> -if VIRTUALIZATION
> -
>  config KVM
>  	tristate "Kernel-based Virtual Machine (KVM) support"
>  	depends on HAVE_KVM
> @@ -93,9 +80,3 @@ config KVM_DEVICE_ASSIGNMENT
>  
>  	  If unsure, say Y.
>  
> -# OK, it's a little counter-intuitive to do this, but it puts it neatly under
> -# the virtualization menu.
> -source drivers/vhost/Kconfig
> -source drivers/lguest/Kconfig
> -
> -endif # VIRTUALIZATION
> _
> 

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

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

[Paolo Bonzini]

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>

Re: [PATCH 1/2] x86 Kconfig: create x86/Kconfig.virt

[Borislav Petkov]

On Mon, Jan 13, 2014 at 04:11:38PM -0800, Dave Hansen wrote:
> 
> From: Dave Hansen <dave.hansen@linux.intel.com>
> 
> Right now, there is a "Enable paravirtualization code" option in
> the "Processor Features" menu, which means Xen.  There is also a
> group of host-side paravirtualization options specific to KVM
> under the top-level "Virtualization" menu.
> 
> I think it makes a lot of sense to group the host and guest side
> things together, especially since the top-level "Virtualization"
> menu is so sparsely populated.

Whoops, those are 4 years old and look forgotten. The idea still makes
sense though, IMO. You could refresh them, if bored ... :-)

Thx.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--