Re: [libvirt] [PATCH] kvm: maxVCPU runtime detection

[Guido Günther <agx sigxcpu org>]

On Fri, Aug 22, 2008 at 07:26:12PM +0200, Jim Meyering wrote:
[..snip..] 
> I've just checked up to date rawhide and debian unstable systems.
> Both had this:
> 
>     $ grep KVM_CHECK_EXTENSION /usr/include/linux/kvm.h
>     #define KVM_CHECK_EXTENSION       _IO(KVMIO,   0x03)
> 
> But rawhide lacks KVM_CAP_NR_VCPUS, while Debian has it.
> 
>     $ grep -r KVM_CAP_NR_VCPUS /usr/include/linux/kvm.h
>     #define KVM_CAP_NR_VCPUS 9       /* returns max vcpus per vm */

Debian has it only in unstable not in testing. That's why I added the
header check as well as the "#if defined(KVM_CAP_NR_VCPUS)" - the code
stays as is for old header files and uses the definition (and therefore
the ioctl) if available. 
Rawhide will get the defintion with the next libc header update I guess.
 -- Guido