Re: Xen 4.14.1 on RPI4: device tree generation failed

[Tamas K Lengyel <tamas.k.lengyel@xxxxxxxxx>]

On Mon, Feb 1, 2021 at 4:24 PM Elliott Mitchell <ehem+xen@xxxxxxx> wrote:
>
> On Mon, Feb 01, 2021 at 10:23:34AM -0500, Tamas K Lengyel wrote:
> > On Mon, Feb 1, 2021 at 12:54 AM Elliott Mitchell <ehem+xen@xxxxxxx> wrote:
> > > On Sun, Jan 31, 2021 at 09:43:13PM -0500, Tamas K Lengyel wrote:
> > > > No output from dom0 received even with the added console options
> > > > (+earlyprintk=xen). The kernel build was from rpi-5.10.y
> > > > c9226080e513181ffb3909a905e9c23b8a6e8f62. I'll check if it still boots
> > > > with 4.19 next.
> > >
> > > So, their current HEAD.  This reads like you've got a problematic kernel
> > > configuration.  What procedure are you following to generate the
> > > configuration you use?
> > >
> > > Using their upstream as a base and then adding the configuration options
> > > for Xen has worked fairly well for me (`make bcm2711_defconfig`,
> > > `make menuconfig`, `make zImage`).
> > >
> > > Notably the options:
> > > CONFIG_PARAVIRT
> > > CONFIG_XEN_DOM0
> > > CONFIG_XEN
> > > CONFIG_XEN_BLKDEV_BACKEND
> > > CONFIG_XEN_NETDEV_BACKEND
> > > CONFIG_HVC_XEN
> > > CONFIG_HVC_XEN_FRONTEND
> > >
> > > Should be set to "y".
> >
> > Yes, these configs are all set the same way for all Linux builds by the 
> > script:
> >         make O=.build-arm64 ARCH=arm64
> > CROSS_COMPILE=aarch64-none-linux-gnu- bcm2711_defconfig xen.config
> >
> > I tried with both the rpi-5.10.y and rpi-5.9.y, neither boot up as
> > dom0. So far only 4.19 boots.
>
> So you're using a scripted procedure to generate the configuration.  The
> actual kernel configuration is saved in the file ".config" in the build
> directory.  Could you confirm whether those are actually being set?
>
> Try running `grep -eCONFIG_PARAVIRT -eCONFIG_XEN_DOM0 -eCONFIG_XEN
> -eCONFIG_HVC_XEN -eCONFIG_HVC_XEN_FRONTEND .config`, those 5 must
> be "=y".  Various kernel configuration options depend upon others, so
> there could be potential you need to set one before those get enabled.

These options are all set, it was one of the first things I did was to
confirm in the actual config file. There is no output from 5.9 or
5.10. With 4.19 and 5.4 there is, but only 4.19 actually manages to
boot to a workable state.

Tamas