Re: [Xen-users] How to build a PV domU kernel

[lei yang <yanglei.fage@xxxxxxxxx>]

On Fri, May 14, 2010 at 12:17 AM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:

On Fri, May 14, 2010 at 12:10:28AM +0800, lei yang wrote:
>    On Thu, May 13, 2010 at 11:53 PM, Pasi Kärkkäinen <[1]pasik@xxxxxx> wrote:
>
>      On Thu, May 13, 2010 at 11:47:03PM +0800, lei yang wrote:
>      >    On Thu, May 13, 2010 at 8:33 PM, Pasi Kärkkäinen

>      <[1][2]pasik@xxxxxx> wrote:
>      >
>      >      On Thu, May 13, 2010 at 11:13:00AM +0800, lei yang wrote:
>      >      >    Hi All,
>      >      >
>      >      >    I download a xen 4.0.0, after I run "make world" I got a
>      2.6.33.1
>      >      kernel,
>      >      >    it should be a kernel for Dom0, my question is " how to get
>      a domU
>      >      kernel
>      >      >    for 2.6.33.1"
>      >      >
>      >
>      >      The same kernel can be used also for domU.
>      >
>      >
>      >    a.I'm confused by this in the readme of xen4.0.0, I saw we can get
>      domU
>      >    with "   KERNELS="linux-2.6-xen0 linux-2.6-xenU"" when run "make",
>      and I
>      >    got two kernel one is for dom0, anther is domU, the size of dom0 is
>      bigger
>      >    than domU, do you mean we can ignor this(KERNELS="linux-2.6-xen0
>      >    linux-2.6-xenU), just use one dom0 kernel for domU?
>      >
>
>      Those options are required for building the linux-2.6.18-xen based "old"
>      xenlinux kernels.
>      If you don't specify KERNELS= at all, and only use "make world", it'll
>      build you a pvops kernel.
>      >    b. if I saw some document, they tell "the dom0 need the patch for
>      xen "
>      >    eg:wget
>      >

>       [2][3]http://gentoo-xen-kernel.googlecode.com/files/xen-patches-2.6.33-1.tar.bz2

>      >    , my question is "does domU kernel need this patch?
>      >
>
>      If you want to build a Xenlinux based domU kernel, then you need that
>      patch.
>      pvops kernels don't require that patch.
>

>      See [4]http://wiki.xensource.com/xenwiki/XenDom0Kernels for more

>      information.
>      That says Dom0Kernels, but it also applies for domU kernels.
>
>
>    do you mean the Dom0 kernel *image* can be used for DomU? one quick
>    quesion here"
>    dom0 enabled CONFIG_XEN_DOM0=y , if we use dom0 kernel image for domU, do
>    we need to disable this CONFIG_XEN_DOM0
>

The exact same built binary *image* can be used for dom0 and domU.

When booting the same image as domU it won't have access to any of the
privileged (dom0) things, so having the CONFIG_XEN_DOM0 enabled doesn't matter.

 

 

It seems the patch for dom0 doesn't affect domU boot when use dom0 kernel for domU.

domU doesn't need that patch.

 

Lei

 

 

-- Pasi

>    Thanks
>    Lei
>
>
>
>      You can see the two different types described there (Xenlinux and
>      pvops).
>      >
>      >    c.if domU does not use that patch, and I download a kernel from

>      >    [3][5]kernel.org, which kernel config need to be opened for
>      >     pvops Xen domU,
>      >
>
>      You don't need a special config for upstream/[6]kernel.org pvops based

>      domU kernel.
>      You just need to enable the pvops Xen domU related options.

>      See: [7]http://wiki.xensource.com/xenwiki/XenParavirtOps

>
>      >
>      >    d.which kernel version is the latest one for dom0 kernel support, I
>      go to

>      >    [4][8]http://code.google.com/p/gentoo-xen-kernel/updates/list , I

>      find the
>      >    latest patch for dom0 is xen-patches-2.6.33-1.tar.bz2, does it mean
>      the
>      >    *official* latest one is 2.6.33? and how about domU,which is the
>      >    latest kernel version for domU, I think it may be the latest one in

>      >    [5][9]kernel.org(2.6.43-r6)

>      >
>
>      The latest Xenlinux patches are for 2.6.33, yes.
>      I'd recommend using 2.6.32 instead, since that's the long term supported
>      kernel,
>      and it's picked up by multiple Linux distros.
>
>      Also the latest recommended pvops based dom0 kernel is 2.6.32,
>      it's available in Jeremy's xen.git xen/stable-2.6.32.x branch.

>      See [10]http://wiki.xensource.com/xenwiki/XenParavirtOps for more

>      information.
>
>      >
>      >    Sorry to ask for so many quesion, I'm new to xen
>      >
>
>      No problems.
>
>      -- Pasi
>
>      >    Thanks
>      >    Lei
>      >
>      >
>      >
>      >
>      >

>      >      Or then you can grab a kernel from [6][11]kernel.org and build it

>      with pvops
>      >      Xen domU support
>      >      enabled.
>      >
>      >      Or you can get any of the other xenlinux source trees.
>      >      -- Pasi
>      >
>      >    --
>      >    "We learn from failure, not from success!"
>      >
>      > References
>      >
>      >    Visible links

>      >    1. mailto:[12]pasik@xxxxxx
>      >    2.
>      [13]http://gentoo-xen-kernel.googlecode.com/files/xen-patches-2.6.33-1.tar.bz2
>      >    3. [14]http://kernel.org/
>      >    4. [15]http://code.google.com/p/gentoo-xen-kernel/updates/list
>      >    5. [16]http://kernel.org/
>      >    6. [17]http://kernel.org/

>
>    --
>    "We learn from failure, not from success!"
>

> References
>
>    Visible links
>    1. mailto:pasik@xxxxxx

>    2. mailto:pasik@xxxxxx
>    3. http://gentoo-xen-kernel.googlecode.com/files/xen-patches-2.6.33-1.tar.bz2
>    4. http://wiki.xensource.com/xenwiki/XenDom0Kernels

>    5. http://kernel.org/
>    6. http://kernel.org/

>    7. http://wiki.xensource.com/xenwiki/XenParavirtOps
>    8. http://code.google.com/p/gentoo-xen-kernel/updates/list
>    9. http://kernel.org/
>   10. http://wiki.xensource.com/xenwiki/XenParavirtOps
>   11. http://kernel.org/
>   12. mailto:pasik@xxxxxx
>   13. http://gentoo-xen-kernel.googlecode.com/files/xen-patches-2.6.33-1.tar.bz2
>   14. http://kernel.org/
>   15. http://code.google.com/p/gentoo-xen-kernel/updates/list
>   16. http://kernel.org/
>   17. http://kernel.org/

-- 
"We learn from failure, not from success!"
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