Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Hollis Blanchard]

On Sun, 02 Dec 2007 10:50:06 +0200, Avi Kivity wrote:
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 368864d..eded44e
> 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -112,6 +112,9 @@ config GENERIC_TIME_VSYSCALL
>  	bool
>  	default X86_64
>  
> +config ARCH_SUPPORTS_KVM
> +	bool
> +	default y
>  
>  
>  
> diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig index
> 6569206..4086080 100644
> --- a/drivers/kvm/Kconfig
> +++ b/drivers/kvm/Kconfig
> @@ -3,7 +3,7 @@
>  #
>  menuconfig VIRTUALIZATION
>  	bool "Virtualization"
> -	depends on X86
> +	depends on ARCH_SUPPORTS_KVM || X86
>  	default y
>  	---help---
>  	  Say Y here to get to see options for using your Linux host to 
run
>  	  other

I think this approach is fine, but don't forget that lguest was snuck 
into drivers/kvm/Kconfig. It might be a good idea to move 
CONFIG_VIRTUALIZATION into drivers/Kconfig at this point... maybe a task 
for Rusty.

-- 
Hollis Blanchard
IBM Linux Technology Center


-------------------------------------------------------------------------
SF.Net email is sponsored by: The Future of Linux Business White Paper
from Novell.  From the desktop to the data center, Linux is going
mainstream.  Let it simplify your IT future.
http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Avi Kivity]

Hollis Blanchard wrote:
>>  
>> diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig index
>> 6569206..4086080 100644
>> --- a/drivers/kvm/Kconfig
>> +++ b/drivers/kvm/Kconfig
>> @@ -3,7 +3,7 @@
>>  #
>>  menuconfig VIRTUALIZATION
>>  	bool "Virtualization"
>> -	depends on X86
>> +	depends on ARCH_SUPPORTS_KVM || X86
>>  	default y
> I think this approach is fine, but don't forget that lguest was snuck 
> into drivers/kvm/Kconfig. 

Actually I considered this. X86 in the depends statement above is short 
for "ARCH_SUPPORTS_LGUEST"; otherwise it is not needed.


> It might be a good idea to move 
> CONFIG_VIRTUALIZATION into drivers/Kconfig at this point

I prefer a top-level virt/ and arch/*/virt/.

-- 
error compiling committee.c: too many arguments to function


-------------------------------------------------------------------------
SF.Net email is sponsored by: The Future of Linux Business White Paper
from Novell.  From the desktop to the data center, Linux is going
mainstream.  Let it simplify your IT future.
http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Olaf Hering]

> Currently, make headers_check barfs due to <asm/kvm.h>, which <linux/kvm.h>
> includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export kvm.h
> only if the arch actually supports it.

This makes headers_install_all unreliable.
linux/kvm.h will not be exported, depending on what system the libc
headers will be generated. Please revert
fb56dbb31c4738a3918db81fd24da732ce3b4ae6 and find a different way to run
make headers_check successfully.

Similar CONFIG_* usage is in include/asm-cris/Kbuild.
Fortunately, its not relevant in practice.

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Avi Kivity]

Olaf Hering wrote:
>> Currently, make headers_check barfs due to <asm/kvm.h>, which <linux/kvm.h>
>> includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export kvm.h
>> only if the arch actually supports it.
>>     
>
> This makes headers_install_all unreliable.
> linux/kvm.h will not be exported, depending on what system the libc
> headers will be generated. 

I see.  Any suggestions besides adding lots of asm-*/kvm.h?

-- 
Any sufficiently difficult bug is indistinguishable from a feature.

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Sam Ravnborg]

On Wed, Feb 13, 2008 at 09:43:49AM +0200, Avi Kivity wrote:
> Olaf Hering wrote:
> >>Currently, make headers_check barfs due to <asm/kvm.h>, which 
> >><linux/kvm.h>
> >>includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export 
> >>kvm.h
> >>only if the arch actually supports it.
> >>    
> >
> >This makes headers_install_all unreliable.
> >linux/kvm.h will not be exported, depending on what system the libc
> >headers will be generated. 
> 
> I see.  Any suggestions besides adding lots of asm-*/kvm.h?

Do not include asm/kvm.h from linux/kvm.h.
And in the few places where it is needed explicit include asm/kvm.h before
linux/kvm.h.

Alternatively inlcude asm/kvm.h inside #ifdef KERNEL"
so only userspace has to do explicit include of asm before linux variant.

	Sam

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Avi Kivity]

Sam Ravnborg wrote:
> On Wed, Feb 13, 2008 at 09:43:49AM +0200, Avi Kivity wrote:
>   
>> Olaf Hering wrote:
>>     
>>>> Currently, make headers_check barfs due to <asm/kvm.h>, which 
>>>> <linux/kvm.h>
>>>> includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export 
>>>> kvm.h
>>>> only if the arch actually supports it.
>>>>    
>>>>         
>>> This makes headers_install_all unreliable.
>>> linux/kvm.h will not be exported, depending on what system the libc
>>> headers will be generated. 
>>>       
>> I see.  Any suggestions besides adding lots of asm-*/kvm.h?
>>     
>
> Do not include asm/kvm.h from linux/kvm.h.
> And in the few places where it is needed explicit include asm/kvm.h before
> linux/kvm.h.
>
> Alternatively inlcude asm/kvm.h inside #ifdef KERNEL"
> so only userspace has to do explicit include of asm before linux variant.
>   

That's not very nice for userspace, which needs asm/kvm.h for the arch 
specific parts of the interface.  I'll add asm-*/kvm.h.

-- 
Any sufficiently difficult bug is indistinguishable from a feature.

Re: KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

[Olaf Hering]

On Thu, Feb 14, Avi Kivity wrote:

> Sam Ravnborg wrote:
>> On Wed, Feb 13, 2008 at 09:43:49AM +0200, Avi Kivity wrote:
>>   
>>> Olaf Hering wrote:
>>>     
>>>>> Currently, make headers_check barfs due to <asm/kvm.h>, which 
>>>>> <linux/kvm.h>
>>>>> includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export 
>>>>> kvm.h
>>>>> only if the arch actually supports it.
>>>>>            
>>>> This makes headers_install_all unreliable.
>>>> linux/kvm.h will not be exported, depending on what system the libc
>>>> headers will be generated.       
>>> I see.  Any suggestions besides adding lots of asm-*/kvm.h?
>>>     
>>
>> Do not include asm/kvm.h from linux/kvm.h.
>> And in the few places where it is needed explicit include asm/kvm.h before
>> linux/kvm.h.
>>
>> Alternatively inlcude asm/kvm.h inside #ifdef KERNEL"
>> so only userspace has to do explicit include of asm before linux variant.
>>   
>
> That's not very nice for userspace, which needs asm/kvm.h for the arch 
> specific parts of the interface.  I'll add asm-*/kvm.h.

Can you please revert this change before 2.6.25 is released?
'make headers_install_all' has to be reliable.

 commit fb56dbb31c4738a3918db81fd24da732ce3b4ae6
 Author: Avi Kivity <avi@qumranet.com>
 Date:   Sun Dec 2 10:50:06 2007 +0200

    KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

    Currently, make headers_check barfs due to <asm/kvm.h>, which <linux/kvm.h>
    includes, not existing.  Rather than add a zillion <asm/kvm.h>s, export kvm.h
    only if the arch actually supports it.