Re: 5.7.0 / BUG: kernel NULL pointer dereference / setup_cpu_watcher

[Christian Kujau <lists@xxxxxxxxxxxxxxx>]

On Fri, 5 Jun 2020, Jürgen Groß wrote:
> Do you happen to start the guest with vcpus < maxvcpus?

Indeed, I was booting with vcpus=2, maxvcpus=4. Setting both to the same 
value made the domU boot.

> If yes there is already a patch pending for 5.8:
> https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git/commit/?h=for-linus-5.8&id=c54b071c192dfe8061336f650ceaf358e6386e0b

Applied that manually and now the system boots even with vcpus < maxvcpus. 
So, if this still matters:
 
   Tested-by: Christian Kujau <lists@xxxxxxxxxxxxxxx>

Thank you for your response, and the fix!

Christian.
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