I got the 2.6.39-rc3 kernel full source from http://www.kernel.org.
And CONFIG_PARAVIRT is turned on.

Here is the steps I configure the kernel:
1. Processor type and features
High Memory Support--->
64GB
(Then I can see PAE and some xen related options)

2. Processor type and features
--- Paravirtualized guest support--->
[*]Xen guest support

3. Device Drivers
Xen Driver Support--->
(All turned on by default)

4. Device Drivers
Metwork device support--->
<*> Xen network device frontend driver
<*> Xen backend network device

5. Bus options
<*>Xen PCI Frontend 




011-04-19 



Wishes
Ruozeng W 



发件人： Konrad Rzeszutek Wilk 
发送时间： 2011-04-19  00:40:18 
收件人： ruozeng.w 
抄送： Pasi K鋜kk鋓nen; xen-devel 
主题： Re: Re: [Xen-devel] Xend cannot start 
 
On Mon, Apr 18, 2011 at 11:48:19PM +0800, ruozeng.w wrote:
> I also  found that when "make modules_install" executed, it didn't install any module under /drivers/xen/, but I don't know why.
> 
> In the kernel .config file, I can't find some item the Pv_ops direction mentioned, such as CONFIG_XEN_PCI, CONFIG_XEN_KBDDEV_FRONTEND, CONFIG_XEN_BLKDEV_BACKEND, and can't find the definition of these options(grep returns nothing), so I think they might be cancelled in new 2.6.39 kernel.
Where did you get the 2.6.39 kernel from?
Did you turn on CONFIG_PARAVIRT=y