[PATCH] make KVM selectable again

[PATCH] make KVM selectable again

[Dave Hansen]

Current git for me (b1d0e4f535e10775cffde922208b49629169aeaa) doesn't
let me build KVM.  In fact, I don't seem to have *ANY* kvm-related
symbols in my .config at all.

I've verified that arch/x86/kvm/Kconfig was getting run by putting some
comments in it.  It seems to me like just putting:

	config HAVE_KVM
	       bool

isn't letting anything come into my .config at all.  I'm not sure why we
do that, and then have:

	select HAVE_KVM

in arch/x86/Kconfig.

This patch just defines HAVE_KVM in the x86 Kconfig and is done with it.
Seems to work for me.

Was there some reason that it was done this way?  Was it ever tested?

-- Dave

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 65a70b7..cbbf35d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -115,7 +115,8 @@ config ARCH_HAS_CPU_RELAX
 config HAVE_SETUP_PER_CPU_AREA
 	def_bool X86_64
 
-select HAVE_KVM
+config HAVE_KVM
+	def_bool y
 
 config ARCH_HIBERNATION_POSSIBLE
 	def_bool y
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 41962e7..f2177ec 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -1,8 +1,6 @@
 #
 # KVM configuration
 #
-config HAVE_KVM
-       bool
 
 menuconfig VIRTUALIZATION
 	bool "Virtualization"

Re: [PATCH] make KVM selectable again

[Ingo Molnar]

* Dave Hansen <haveblue@us.ibm.com> wrote:

>  config HAVE_SETUP_PER_CPU_AREA
>  	def_bool X86_64
>  
> -select HAVE_KVM
> +config HAVE_KVM
> +	def_bool y

i think it might be better to just move the select to after the "config 
X86" option. (this is a legitimate use of select) Sam, do you concur?

(but, your current fix should go in ASAP, so no objections from me.)

	Ingo

Re: [PATCH] make KVM selectable again

[Sam Ravnborg]

On Sat, Feb 09, 2008 at 10:24:01PM +0100, Ingo Molnar wrote:
> 
> * Dave Hansen <haveblue@us.ibm.com> wrote:
> 
> >  config HAVE_SETUP_PER_CPU_AREA
> >  	def_bool X86_64
> >  
> > -select HAVE_KVM
> > +config HAVE_KVM
> > +	def_bool y
> 
> i think it might be better to just move the select to after the "config 
> X86" option. (this is a legitimate use of select) Sam, do you concur?

Correct.
We should see it used like this:

config X86
	select HAVE_KVM

	Sam

Re: [PATCH] make KVM selectable again

[Sam Ravnborg]

Hi Dave.
> 
> I've verified that arch/x86/kvm/Kconfig was getting run by putting some
> comments in it.  It seems to me like just putting:
> 
> 	config HAVE_KVM
> 	       bool
> 
> isn't letting anything come into my .config at all.  I'm not sure why we
> do that, and then have:
> 
> 	select HAVE_KVM
> 
> in arch/x86/Kconfig.

See rationale in Documentation/kbuild/kconfig-language.txt - last chapter.
In this case the select was just placed wrongly.

	Sam

Re: [PATCH] make KVM selectable again

[Balbir Singh]

On Feb 10, 2008 2:29 AM, Dave Hansen <haveblue@us.ibm.com> wrote:
> Current git for me (b1d0e4f535e10775cffde922208b49629169aeaa) doesn't
> let me build KVM.  In fact, I don't seem to have *ANY* kvm-related
> symbols in my .config at all.
>
> I've verified that arch/x86/kvm/Kconfig was getting run by putting some
> comments in it.  It seems to me like just putting:
>
>         config HAVE_KVM
>                bool
>
> isn't letting anything come into my .config at all.  I'm not sure why we
> do that, and then have:
>
>         select HAVE_KVM
>
> in arch/x86/Kconfig.
>
> This patch just defines HAVE_KVM in the x86 Kconfig and is done with it.
> Seems to work for me.
>
> Was there some reason that it was done this way?  Was it ever tested?
>
> -- Dave
>
> Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 65a70b7..cbbf35d 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -115,7 +115,8 @@ config ARCH_HAS_CPU_RELAX
>  config HAVE_SETUP_PER_CPU_AREA
>         def_bool X86_64
>
> -select HAVE_KVM
> +config HAVE_KVM
> +       def_bool y
>
>  config ARCH_HIBERNATION_POSSIBLE
>         def_bool y
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index 41962e7..f2177ec 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -1,8 +1,6 @@
>  #
>  # KVM configuration
>  #
> -config HAVE_KVM
> -       bool
>
>  menuconfig VIRTUALIZATION
>         bool "Virtualization"
>

Hi, Dave,

I did not see your email, until just now. I've posted a patch at
http://lkml.org/lkml/2008/2/10/26. Avi has acked it

Balbir