Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Pasi Kärkkäinen]

Hello,

I know there has been some discussion about this already, 
but I just noticed it myself when I upgraded my testbox.

So, I have Xen 4.0.0, and the latest xen/stable-2.6.32.x dom0 kernel, ie. 2.6.32.15.

On system startup I notice xenstored and xend fail to start.
I look around and notice /dev/xen/ is empty.

I do "rmmod xen-evtchn" and "modprobe xen-evtchn" and then I have:

# ls -la /dev/xen
total 0
drwxr-xr-x  2 root root     60 Jun 19 15:22 .
drwxr-xr-x 20 root root   4580 Jun 19 15:20 ..
crw-rw----  1 root root 10, 58 Jun 19 15:22 evtchn

Based on some earlier emails it has wrong major/minor? 

Also "modprobe xen-gntdev" gives this:

# ls -la /dev/xen
total 0
0 crw-rw---- 1 root root 10, 58 Jun 19 15:22 evtchn
0 crw-rw---- 1 root root 10, 57 Jun 19 15:25 gntdev

So what's the actual problem here? I guess something got changed in the kernel,
and now xen tools/scripts should create the devnodes with a different major/minor? 

Is the correct fix to upgrade Xen to 4.0.1-rcX ? 

I just want to get this correct so I can update the wiki pages.. 
it seems many people hit this problem.

Thanks!

-- Pasi

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Boris Derzhavets]

[-- Attachment #1.1: Type: text/plain, Size: 1965 bytes --]

> Is the correct fix to upgrade Xen to 4.0.1-rcX ? 

Via my experience rc2 should be good.
Similar question was asked by myself some time ago. 
It's on the list.

Boris.
P.S. Some CS from xen-unstable ( libxc related) was back ported to xen-4-testing.hg.
There was also Keir's feed regarding this issue.

--- On Sat, 6/19/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:

From: Pasi Kärkkäinen <pasik@iki.fi>
Subject: [Xen-devel] Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting
To: xen-devel@lists.xensource.com
Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>
Date: Saturday, June 19, 2010, 8:32 AM

Hello,

I know there has been some discussion about this already, 
but I just noticed it myself when I upgraded my testbox.

So, I have Xen 4.0.0, and the latest xen/stable-2.6.32.x dom0 kernel, ie. 2.6.32.15.

On system startup I notice xenstored and xend fail to start.
I look around and notice /dev/xen/ is empty.

I do "rmmod xen-evtchn" and "modprobe xen-evtchn" and then I have:

# ls -la /dev/xen
total 0
drwxr-xr-x  2 root root     60 Jun 19 15:22 .
drwxr-xr-x 20 root root   4580 Jun 19 15:20 ..
crw-rw----  1 root root 10, 58 Jun 19 15:22 evtchn

Based on some earlier emails it has wrong major/minor? 

Also "modprobe xen-gntdev" gives this:

# ls -la /dev/xen
total 0
0 crw-rw---- 1 root root 10, 58 Jun 19 15:22 evtchn
0 crw-rw---- 1 root root 10, 57 Jun 19 15:25 gntdev

So what's the actual problem here? I guess something got changed in the kernel,
and now xen tools/scripts should create the devnodes with a different major/minor? 

Is the correct fix to upgrade Xen to 4.0.1-rcX ? 

I just want to get this correct so I can update the wiki pages.. 
it seems many people hit this problem.

Thanks!

-- Pasi


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



      

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http://lists.xensource.com/xen-devel

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Pasi Kärkkäinen]

On Sat, Jun 19, 2010 at 05:44:03AM -0700, Boris Derzhavets wrote:
>    > Is the correct fix to upgrade Xen to 4.0.1-rcX ?
> 
>    Via my experience rc2 should be good.
>    Similar question was asked by myself some time ago.
>    It's on the list.
> 
>    Boris.
>    P.S. Some CS from xen-unstable ( libxc related) was back ported to
>    xen-4-testing.hg.
>    There was also Keir's feed regarding this issue.
> 

Looks like it's this one in xen-4.0.1-rc2-pre:
http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2

What was the corresponding changeset/patch in xen/stable-2.6.32.x that breaks things with Xen 4.0.0 ?

-- Pasi


>    --- On Sat, 6/19/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> 
>      From: Pasi Kärkkäinen <pasik@iki.fi>
>      Subject: [Xen-devel] Latest pvops dom0 kernel and missing
>      /dev/xen/evtchn, xenstored and xend not starting
>      To: xen-devel@lists.xensource.com
>      Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>
>      Date: Saturday, June 19, 2010, 8:32 AM
> 
>      Hello,
> 
>      I know there has been some discussion about this already,
>      but I just noticed it myself when I upgraded my testbox.
> 
>      So, I have Xen 4.0.0, and the latest xen/stable-2.6.32.x dom0 kernel,
>      ie. 2.6.32.15.
> 
>      On system startup I notice xenstored and xend fail to start.
>      I look around and notice /dev/xen/ is empty.
> 
>      I do "rmmod xen-evtchn" and "modprobe xen-evtchn" and then I have:
> 
>      # ls -la /dev/xen
>      total 0
>      drwxr-xr-x  2 root root     60 Jun 19 15:22 .
>      drwxr-xr-x 20 root root   4580 Jun 19 15:20 ..
>      crw-rw----  1 root root 10, 58 Jun 19 15:22 evtchn
> 
>      Based on some earlier emails it has wrong major/minor?
> 
>      Also "modprobe xen-gntdev" gives this:
> 
>      # ls -la /dev/xen
>      total 0
>      0 crw-rw---- 1 root root 10, 58 Jun 19 15:22 evtchn
>      0 crw-rw---- 1 root root 10, 57 Jun 19 15:25 gntdev
> 
>      So what's the actual problem here? I guess something got changed in the
>      kernel,
>      and now xen tools/scripts should create the devnodes with a different
>      major/minor?
> 
>      Is the correct fix to upgrade Xen to 4.0.1-rcX ?
> 
>      I just want to get this correct so I can update the wiki pages..
>      it seems many people hit this problem.
> 
>      Thanks!
> 
>      -- Pasi
> 
>      _______________________________________________
>      Xen-devel mailing list
>      [1]Xen-devel@lists.xensource.com
>      [2]http://lists.xensource.com/xen-devel
> 
> References
> 
>    Visible links
>    1. file:///mc/compose?to=Xen-devel@lists.xensource.com
>    2. http://lists.xensource.com/xen-devel

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Boris Derzhavets]

[-- Attachment #1.1: Type: text/plain, Size: 3788 bytes --]

> Looks like it's this one in xen-4.0.1-rc2-pre:
> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2

I believe you are right.

> What
 was the corresponding changeset/patch in xen/stable-2.6.32.x that 
breaks things > with Xen 4.0.0 ?

If you mean PV network issue after merge netback-tasklets . I don't remember commit
to revert. I guess in meantime patches from Ian Campbell and Dongxiao Xu have been
applied . Tip 01d9fbca207ec232c758d991d66466fc6e38349e works for me.

Boris.
--- On Sat, 6/19/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:

From: Pasi Kärkkäinen <pasik@iki.fi>
Subject: Re: [Xen-devel] Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting
To: "Boris Derzhavets" <bderzhavets@yahoo.com>
Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>, xen-devel@lists.xensource.com
Date: Saturday, June 19, 2010, 9:18 AM

On Sat, Jun 19, 2010 at 05:44:03AM -0700, Boris Derzhavets wrote:
>    > Is the correct fix to upgrade Xen to 4.0.1-rcX ?
> 
>    Via my experience rc2 should be good.
>    Similar question was asked by myself some time ago.
>    It's on the list.
> 
>    Boris.
>    P.S. Some CS from xen-unstable ( libxc related) was back ported to
>    xen-4-testing.hg.
>    There was also Keir's feed regarding this issue.
> 

Looks like it's this one in xen-4.0.1-rc2-pre:
http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2

What was the corresponding changeset/patch in xen/stable-2.6.32.x that breaks things with Xen 4.0.0 ?

-- Pasi


>    --- On Sat, 6/19/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> 
>      From: Pasi Kärkkäinen <pasik@iki.fi>
>      Subject: [Xen-devel] Latest pvops dom0 kernel and missing
>      /dev/xen/evtchn, xenstored and xend not starting
>      To: xen-devel@lists.xensource.com
>      Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>
>      Date: Saturday, June 19, 2010, 8:32 AM
> 
>      Hello,
> 
>      I know there has been some discussion about this already,
>      but I just noticed it myself when I upgraded my testbox.
> 
>      So, I have Xen 4.0.0, and the latest xen/stable-2.6.32.x dom0 kernel,
>      ie. 2.6.32.15.
> 
>      On system startup I notice xenstored and xend fail to start.
>      I look around and notice /dev/xen/ is empty.
> 
>      I do "rmmod xen-evtchn" and "modprobe xen-evtchn" and then I have:
> 
>      # ls -la /dev/xen
>      total 0
>      drwxr-xr-x  2 root root     60 Jun 19 15:22 .
>      drwxr-xr-x 20 root root   4580 Jun 19 15:20 ..
>      crw-rw----  1 root root 10, 58 Jun 19 15:22 evtchn
> 
>      Based on some earlier emails it has wrong major/minor?
> 
>      Also "modprobe xen-gntdev" gives this:
> 
>      # ls -la /dev/xen
>      total 0
>      0 crw-rw---- 1 root root 10, 58 Jun 19 15:22 evtchn
>      0 crw-rw---- 1 root root 10, 57 Jun 19 15:25 gntdev
> 
>      So what's the actual problem here? I guess something got changed in the
>      kernel,
>      and now xen tools/scripts should create the devnodes with a different
>      major/minor?
> 
>      Is the correct fix to upgrade Xen to 4.0.1-rcX ?
> 
>      I just want to get this correct so I can update the wiki pages..
>      it seems many people hit this problem.
> 
>      Thanks!
> 
>      -- Pasi
> 
>      _______________________________________________
>      Xen-devel mailing list
>      [1]Xen-devel@lists.xensource.com
>      [2]http://lists.xensource.com/xen-devel
> 
> References
> 
>    Visible links
>    1. file:///mc/compose?to=Xen-devel@lists.xensource.com
>    2. http://lists.xensource.com/xen-devel

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



      

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http://lists.xensource.com/xen-devel

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Pasi Kärkkäinen]

On Sat, Jun 19, 2010 at 06:32:21AM -0700, Boris Derzhavets wrote:
>    > Looks like it's this one in xen-4.0.1-rc2-pre:
>    [1]> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
> 
>    I believe you are right.
> 
>    > What was the corresponding changeset/patch in xen/stable-2.6.32.x that
>    breaks things > with Xen 4.0.0 ?
> 
>    If you mean PV network issue after merge netback-tasklets . 
>

No, I don't mean that.

I mean older xen/stable-2.6.32.x kernels DO work with xen-4.0.0,
but the latest xen/stable-2.6.32.x does NOT work with xen-4.0.0.

So there is some change/patch in the dom0 kernel that breaks things with xen 4.0.0.


> I don't remember commit
>    to revert. I guess in meantime patches from Ian Campbell and Dongxiao Xu
>    have been
>    applied . Tip 01d9fbca207ec232c758d991d66466fc6e38349e works for me.
> 

The latest xen/stable-2.6.32.x should have the netback/tasklet stuff working again, afaik.
No need for patches or reverts.

-- Pasi

>    Boris.
>    --- On Sat, 6/19/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> 
>      From: Pasi Kärkkäinen <pasik@iki.fi>
>      Subject: Re: [Xen-devel] Latest pvops dom0 kernel and missing
>      /dev/xen/evtchn, xenstored and xend not starting
>      To: "Boris Derzhavets" <bderzhavets@yahoo.com>
>      Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>,
>      xen-devel@lists.xensource.com
>      Date: Saturday, June 19, 2010, 9:18 AM
> 
>      On Sat, Jun 19, 2010 at 05:44:03AM -0700, Boris Derzhavets wrote:
>      >    > Is the correct fix to upgrade Xen to 4.0.1-rcX ?
>      >
>      >    Via my experience rc2 should be good.
>      >    Similar question was asked by myself some time ago.
>      >    It's on the list.
>      >
>      >    Boris.
>      >    P.S. Some CS from xen-unstable ( libxc related) was back ported to
>      >    xen-4-testing.hg.
>      >    There was also Keir's feed regarding this issue.
>      >
> 
>      Looks like it's this one in xen-4.0.1-rc2-pre:
>      [2]http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
> 
>      What was the corresponding changeset/patch in xen/stable-2.6.32.x that
>      breaks things with Xen 4.0.0 ?
> 
>      -- Pasi
> 
>      >    --- On Sat, 6/19/10, Pasi Kärkkäinen <[3]pasik@iki.fi> wrote:
>      >
>      >      From: Pasi Kärkkäinen <[4]pasik@iki.fi>
>      >      Subject: [Xen-devel] Latest pvops dom0 kernel and missing
>      >      /dev/xen/evtchn, xenstored and xend not starting
>      >      To: [5]xen-devel@lists.xensource.com
>      >      Cc: "Jeremy Fitzhardinge" <[6]jeremy@goop.org>
>      >      Date: Saturday, June 19, 2010, 8:32 AM
>      >
>      >      Hello,
>      >
>      >      I know there has been some discussion about this already,
>      >      but I just noticed it myself when I upgraded my testbox.
>      >
>      >      So, I have Xen 4.0.0, and the latest xen/stable-2.6.32.x dom0
>      kernel,
>      >      ie. 2.6.32.15.
>      >
>      >      On system startup I notice xenstored and xend fail to start.
>      >      I look around and notice /dev/xen/ is empty.
>      >
>      >      I do "rmmod xen-evtchn" and "modprobe xen-evtchn" and then I
>      have:
>      >
>      >      # ls -la /dev/xen
>      >      total 0
>      >      drwxr-xr-x  2 root root     60 Jun 19 15:22 .
>      >      drwxr-xr-x 20 root root   4580 Jun 19 15:20 ..
>      >      crw-rw----  1 root root 10, 58 Jun 19 15:22 evtchn
>      >
>      >      Based on some earlier emails it has wrong major/minor?
>      >
>      >      Also "modprobe xen-gntdev" gives this:
>      >
>      >      # ls -la /dev/xen
>      >      total 0
>      >      0 crw-rw---- 1 root root 10, 58 Jun 19 15:22 evtchn
>      >      0 crw-rw---- 1 root root 10, 57 Jun 19 15:25 gntdev
>      >
>      >      So what's the actual problem here? I guess something got changed
>      in the
>      >      kernel,
>      >      and now xen tools/scripts should create the devnodes with a
>      different
>      >      major/minor?
>      >
>      >      Is the correct fix to upgrade Xen to 4.0.1-rcX ?
>      >
>      >      I just want to get this correct so I can update the wiki pages..
>      >      it seems many people hit this problem.
>      >
>      >      Thanks!
>      >
>      >      -- Pasi
>      >
>      >      _______________________________________________
>      >      Xen-devel mailing list
>      >      [1][7]Xen-devel@lists.xensource.com
>      >      [2][8]http://lists.xensource.com/xen-devel
>      >
>      > References
>      >
>      >    Visible links
>      >    1. file:///mc/compose?to=[9]Xen-devel@lists.xensource.com
>      >    2. [10]http://lists.xensource.com/xen-devel
> 
>      _______________________________________________
>      Xen-devel mailing list
>      [11]Xen-devel@lists.xensource.com
>      [12]http://lists.xensource.com/xen-devel
> 
> References
> 
>    Visible links
>    1. http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
>    2. http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
>    3. file:///mc/compose?to=pasik@iki.fi
>    4. file:///mc/compose?to=pasik@iki.fi
>    5. file:///mc/compose?to=xen-devel@lists.xensource.com
>    6. file:///mc/compose?to=jeremy@goop.org
>    7. file:///mc/compose?to=Xen-devel@lists.xensource.com
>    8. http://lists.xensource.com/xen-devel
>    9. file:///mc/compose?to=Xen-devel@lists.xensource.com
>   10. http://lists.xensource.com/xen-devel
>   11. file:///mc/compose?to=Xen-devel@lists.xensource.com
>   12. http://lists.xensource.com/xen-devel

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Jeremy Fitzhardinge]

On 06/19/2010 02:37 PM, Pasi Kärkkäinen wrote:
> On Sat, Jun 19, 2010 at 06:32:21AM -0700, Boris Derzhavets wrote:
>   
>>    > Looks like it's this one in xen-4.0.1-rc2-pre:
>>    [1]> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
>>
>>    I believe you are right.
>>
>>    > What was the corresponding changeset/patch in xen/stable-2.6.32.x that
>>    breaks things > with Xen 4.0.0 ?
>>
>>    If you mean PV network issue after merge netback-tasklets . 
>>
>>     
> No, I don't mean that.
>
> I mean older xen/stable-2.6.32.x kernels DO work with xen-4.0.0,
> but the latest xen/stable-2.6.32.x does NOT work with xen-4.0.0.
>
> So there is some change/patch in the dom0 kernel that breaks things with xen 4.0.0.
>   

376d908f52427591cef4acd172db9c3ef28676ec and
9d85e25edbcb8a684db8470119077475ac4d90b5

    J

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Pasi Kärkkäinen]

On Sat, Jun 19, 2010 at 04:21:54PM +0100, Jeremy Fitzhardinge wrote:
> On 06/19/2010 02:37 PM, Pasi Kärkkäinen wrote:
> > On Sat, Jun 19, 2010 at 06:32:21AM -0700, Boris Derzhavets wrote:
> >   
> >>    > Looks like it's this one in xen-4.0.1-rc2-pre:
> >>    [1]> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
> >>
> >>    I believe you are right.
> >>
> >>    > What was the corresponding changeset/patch in xen/stable-2.6.32.x that
> >>    breaks things > with Xen 4.0.0 ?
> >>
> >>    If you mean PV network issue after merge netback-tasklets . 
> >>
> >>     
> > No, I don't mean that.
> >
> > I mean older xen/stable-2.6.32.x kernels DO work with xen-4.0.0,
> > but the latest xen/stable-2.6.32.x does NOT work with xen-4.0.0.
> >
> > So there is some change/patch in the dom0 kernel that breaks things with xen 4.0.0.
> >   
> 
> 376d908f52427591cef4acd172db9c3ef28676ec and
> 9d85e25edbcb8a684db8470119077475ac4d90b5
> 

Ok, thanks.

I seem to have these major/minors on my devices:

# ls -la /dev/xen
total 0
drwxr-xr-x  2 root root     80 Jun 19 19:17 .
drwxr-xr-x 20 root root   4580 Jun 19 19:33 ..
crw-rw----  1 root root 10, 58 Jun 19 19:17 evtchn
crw-rw----  1 root root 10, 57 Jun 19 19:17 gntdev

Is that correct? They don't seem to match what you pasted earlier..

Then again things seem to work.. I can install new guests using virt-manager etc :)

-- Pasi

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Jeremy Fitzhardinge]

On 06/19/2010 05:38 PM, Pasi Kärkkäinen wrote:
> On Sat, Jun 19, 2010 at 04:21:54PM +0100, Jeremy Fitzhardinge wrote:
>   
>> On 06/19/2010 02:37 PM, Pasi Kärkkäinen wrote:
>>     
>>> On Sat, Jun 19, 2010 at 06:32:21AM -0700, Boris Derzhavets wrote:
>>>   
>>>       
>>>>    > Looks like it's this one in xen-4.0.1-rc2-pre:
>>>>    [1]> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
>>>>
>>>>    I believe you are right.
>>>>
>>>>    > What was the corresponding changeset/patch in xen/stable-2.6.32.x that
>>>>    breaks things > with Xen 4.0.0 ?
>>>>
>>>>    If you mean PV network issue after merge netback-tasklets . 
>>>>
>>>>     
>>>>         
>>> No, I don't mean that.
>>>
>>> I mean older xen/stable-2.6.32.x kernels DO work with xen-4.0.0,
>>> but the latest xen/stable-2.6.32.x does NOT work with xen-4.0.0.
>>>
>>> So there is some change/patch in the dom0 kernel that breaks things with xen 4.0.0.
>>>   
>>>       
>> 376d908f52427591cef4acd172db9c3ef28676ec and
>> 9d85e25edbcb8a684db8470119077475ac4d90b5
>>
>>     
> Ok, thanks.
>
> I seem to have these major/minors on my devices:
>
> # ls -la /dev/xen
> total 0
> drwxr-xr-x  2 root root     80 Jun 19 19:17 .
> drwxr-xr-x 20 root root   4580 Jun 19 19:33 ..
> crw-rw----  1 root root 10, 58 Jun 19 19:17 evtchn
> crw-rw----  1 root root 10, 57 Jun 19 19:17 gntdev
>
> Is that correct? They don't seem to match what you pasted earlier..
>
> Then again things seem to work.. I can install new guests using virt-manager etc :)
>   

The major/minors are completely dynamic, depending on what else you've
got in your kernel.  /proc/misc will tell you what they should be.  The
problem is that (old) libxc has some completely broken code to re-create
the device which ends up destroying any correctly created device if it
fails to determine what the major/minor is - and with the change in
kernel device name, it does fail.

    J

    J

Re: Latest pvops dom0 kernel and missing /dev/xen/evtchn, xenstored and xend not starting

[Pasi Kärkkäinen]

On Sat, Jun 19, 2010 at 06:42:28PM +0100, Jeremy Fitzhardinge wrote:
> On 06/19/2010 05:38 PM, Pasi Kärkkäinen wrote:
> > On Sat, Jun 19, 2010 at 04:21:54PM +0100, Jeremy Fitzhardinge wrote:
> >   
> >> On 06/19/2010 02:37 PM, Pasi Kärkkäinen wrote:
> >>     
> >>> On Sat, Jun 19, 2010 at 06:32:21AM -0700, Boris Derzhavets wrote:
> >>>   
> >>>       
> >>>>    > Looks like it's this one in xen-4.0.1-rc2-pre:
> >>>>    [1]> http://xenbits.xen.org/xen-4.0-testing.hg?rev/0e1521f654f2
> >>>>
> >>>>    I believe you are right.
> >>>>
> >>>>    > What was the corresponding changeset/patch in xen/stable-2.6.32.x that
> >>>>    breaks things > with Xen 4.0.0 ?
> >>>>
> >>>>    If you mean PV network issue after merge netback-tasklets . 
> >>>>
> >>>>     
> >>>>         
> >>> No, I don't mean that.
> >>>
> >>> I mean older xen/stable-2.6.32.x kernels DO work with xen-4.0.0,
> >>> but the latest xen/stable-2.6.32.x does NOT work with xen-4.0.0.
> >>>
> >>> So there is some change/patch in the dom0 kernel that breaks things with xen 4.0.0.
> >>>   
> >>>       
> >> 376d908f52427591cef4acd172db9c3ef28676ec and
> >> 9d85e25edbcb8a684db8470119077475ac4d90b5
> >>
> >>     
> > Ok, thanks.
> >
> > I seem to have these major/minors on my devices:
> >
> > # ls -la /dev/xen
> > total 0
> > drwxr-xr-x  2 root root     80 Jun 19 19:17 .
> > drwxr-xr-x 20 root root   4580 Jun 19 19:33 ..
> > crw-rw----  1 root root 10, 58 Jun 19 19:17 evtchn
> > crw-rw----  1 root root 10, 57 Jun 19 19:17 gntdev
> >
> > Is that correct? They don't seem to match what you pasted earlier..
> >
> > Then again things seem to work.. I can install new guests using virt-manager etc :)
> >   
> 
> The major/minors are completely dynamic, depending on what else you've
> got in your kernel.  /proc/misc will tell you what they should be.  The
> problem is that (old) libxc has some completely broken code to re-create
> the device which ends up destroying any correctly created device if it
> fails to determine what the major/minor is - and with the change in
> kernel device name, it does fail.
> 

Thanks.

I added info about that to XenParavirtOps wiki page.

-- Pasi