On 28.10.21 18:41, Stefano Stabellini wrote:
> On Thu, 28 Oct 2021, Juergen Gross wrote:
>> On 28.10.21 01:24, Stefano Stabellini wrote:
>>> On Wed, 27 Oct 2021, Stefano Stabellini wrote:
>>>> On Wed, 27 Oct 2021, Juergen Gross wrote:
>>>>> On 26.10.21 02:54, Stefano Stabellini wrote:
>>>>>> On Mon, 25 Oct 2021, Juergen Gross wrote:
>>>>>>> On 22.10.21 21:41, Stefano Stabellini wrote:
>>>>>>>> +Juergen
>>>>>>>>
>>>>>>>> On Fri, 22 Oct 2021, Andrew Cooper wrote:
>>>>>>>>> On 22/10/2021 00:08, Stefano Stabellini wrote:
>>>>>>>>>> +# build depends
>>>>>>>>>> +RUN apt-get update && \
>>>>>>>>>> +    apt-get --quiet --yes install \
>>>>>>>>>> +        build-essential \
>>>>>>>>>> +        libssl-dev \
>>>>>>>>>> +        bc \
>>>>>>>>>> +        curl \
>>>>>>>>>> +        flex \
>>>>>>>>>> +        bison \
>>>>>>>>>> +        libelf-dev \
>>>>>>>>>> +        && \
>>>>>>>>>> +    \
>>>>>>>>>> +    # Build the kernel
>>>>>>>>>> +    curl -fsSLO
>>>>>>>>>> https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-"$LINUX_VERSION".tar.xz
>>>>>>>>>> && \
>>>>>>>>>> +    tar xvJf linux-"$LINUX_VERSION".tar.xz && \
>>>>>>>>>> +    cd linux-"$LINUX_VERSION" && \
>>>>>>>>>> +    make defconfig && \
>>>>>>>>>> +    make xen.config && \
>>>>>>>>>> +    cp .config .config.orig && \
>>>>>>>>>> +    cat .config.orig | grep XEN | grep =m |sed 's/=m/=y/g' >>
>>>>>>>>>> .config
>>>>>>>>>> && \
>>>>>>>>>> +    make -j$(nproc) bzImage && \
>>>>>>>>>
>>>>>>>>> defconfig is huuuuge.  Can we use tinyconfig instead?
>>>>>>>>>
>>>>>>>>> Also, you want to turn off CONFIG_MODULES seeing as you only
>>>>>>>>> copy
>>>>>>>>> bzImage to the test.
>>>>>>>>>
>>>>>>>>> This also fixes the fact that `grep XEN` also matches
>>>>>>>>> CONFIG_NETXEN_NIC
>>>>>>>>> which has nothing to do with Xen.
>>>>>>>>
>>>>>>>> Tinyconfig would be a good idea but it crashes on QEMU with the
>>>>>>>> appended
>>>>>>>> boot log. I did:
>>>>>>>>
>>>>>>>> # make tinyconfig
>>>>>>>> # make xen.config
>>>>>>>> # make bzImage
>>>>>>>>
>>>>>>>> Of course we could have our own tailored special kernel config for
>>>>>>>> this
>>>>>>>> kernel but I like the simplicify of "make tinyconfig" or "make
>>>>>>>> defconfig" followed by "make xen.config".
>>>>>>>>
>>>>>>>> Unless you know one kconfig option or two that we need to add to
>>>>>>>> tinyconfig to make it work my preference is to go with defconfig
>>>>>>>> for
>>>>>>>> now.
>>>>>>>
>>>>>>> You will need to add the dom0 and SMP related config options at
>>>>>>> least.
>>>>>>>
>>>>>>> I'll have a look at config.xen, which is a little bit weird: it
>>>>>>> configures the backends, but not dom0.
>>>>>>
>>>>>> Thanks, it would be good if make tinyconfig && make xen.config would
>>>>>> just work on QEMU. In the meantime I'll keep defconfig for this test,
>>>>>> we
>>>>>> can always improve later.
>>>>>
>>>>> Can you please test the attached patch?
>>>>
>>>> Yes, that works, thanks!
>>>
>>> Sorry, I spoke too soon: same error as before:
>>>
>>> https://gitlab.com/xen-project/people/sstabellini/xen/-/jobs/1722909607/raw
>>>
>>> (XEN) Hardware Dom0 crashed: rebooting machine in 5 seconds.
>>>
>>> No output from the kernel.
>>
>> This is not very surprising, as tinyconfig doesn't have CONFIG_PRINTK.
>> BTW, it doesn't have initrd support either (BLK_DEV_RAM and
>> BLK_DEV_INITRD), so I added those to xen.config as well.
>>
>> With the (updated) attached patch the kernel boots fine as dom0 until
>> rootfs is tried to be mounted on a physical machine.
>>
>> I've added CONFIG_BUG, too, in order to have more debugging output if
>> needed.
> 
> Much better, now there is output:
> https://gitlab.com/xen-project/people/sstabellini/xen/-/jobs/1726396600/raw
> 
> This kernel is used as dom0 and from the logs it looks like for dom0 we
> need a couple more things:
> - flocks

CONFIG_FILE_LOCKING probably wants to be added.

> - the kconfig to recognize #!/bin/sh

This is probably CONFIG_BINFMT_SCRIPT.

I'm not sure those should be added to the upstream xen.config.


Juergen