RE: [Xen-ia64-devel] Re: [Xen-devel] PATCH: split smpboot.c and createcpuhotplug.c

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

>From: Tristan Gingold
>Sent: 2006年5月23日 15:30
>
>Le Lundi 22 Mai 2006 17:44, Keir Fraser a écrit :
>> On 22 May 2006, at 08:57, Tristan Gingold wrote:
>> > this patch creates a new file: cpuhotplug.c.  The content is the
>xenbus
>> > handler part of smpboot.c.  The purpose is to be able to share this
>> > part with
>> > other architectures.
>> >
>> > Tested by compiling on i386.
>>
>> This raises the obvious question: why don't you use the rest of our
>> smpboot.c to implement SMP bringup? It's all generic except the bit
>> that sets up VCPU initial context.
>I can see three reasons:
>
>* Only a 10 lines change (IPI handling) was required in the linux kernel to
>run SMP on Xen.  All the other changes were in Xen.
>
>* xen/core/smpboot.c is not a drop in replacement for
>arch/ia64/kernel/smpboot.c  Surgery will be required.
>
>* If we used xen/core/smpboot.c, we'd lose transparent virtualization.
>To
>re-enable it we had to do surgery again.
>
>Tristan.

Can't is_running_on_xen help you with transparent virtualization? Checks 
on several major entry paths should be enough... 

The 2nd point seems more reasonable to me if logic does differ a lot.

Thanks,
Kevin

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel