Re: [PATCH 2/3] automation: Linux 5.10.74 test-artifact

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 29 Oct 2021, Juergen Gross wrote:
> 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.

I don't know either... They are certainly required for dom0, but not for
domU. Do we want xen.config to be for domU only or for domU and dom0? If
we want it to be for both, then CONFIG_FILE_LOCKING and
CONFIG_BINFMT_SCRIPT should be added otherwise not.