Re: 2.6.22-rc4-mm2: kvm compile breakage with X86_CMPXCHG64=n

[Avi Kivity <avi@qumranet.com>]

Adrian Bunk wrote:
> On Wed, Jun 06, 2007 at 10:03:13PM -0700, Andrew Morton wrote:
>   
>> ...
>> Changes since 2.6.22-rc4-mm1:
>> ...
>>  git-kvm.patch
>> ...
>>  git trees
>> ...
>>     
>
> I'm getting the following compile error with CONFIG_X86_CMPXCHG64=n 
> (with -Werror-implicit-function-declaration - otherwise it would be a 
> link error):
>
> <--  snip  -->
>
> ...
>   CC [M]  drivers/kvm/mmu.o
> /home/bunk/linux/kernel-2.6/linux-2.6.22-rc4-mm2/drivers/kvm/mmu.c: In function ‘set_shadow_pte’:
> /home/bunk/linux/kernel-2.6/linux-2.6.22-rc4-mm2/drivers/kvm/mmu.c:199: error: implicit declaration of function ‘set_64bit’
> make[3]: *** [drivers/kvm/mmu.o] Error 1
>
> <--  snip  -->
>   

I've committed the following, which should disable kvm on i486 and below:

diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig
index 2f661e5..33fa28a 100644
--- a/drivers/kvm/Kconfig
+++ b/drivers/kvm/Kconfig
@@ -11,6 +11,7 @@ if VIRTUALIZATION
 config KVM
        tristate "Kernel-based Virtual Machine (KVM) support"
        depends on X86 && EXPERIMENTAL
+       depends on X86_CMPXCHG64 || 64BIT
        ---help---
          Support hosting fully virtualized guest machines using hardware
          virtualization extensions.  You will need a fairly recent


-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.