Re: [PATCH 0/4] xen/arm: Unbreak ACPI

[Julien Grall <julien@xxxxxxx>]

Hi Elliott,

On 09/10/2020 15:22, Elliott Mitchell wrote:
> On Fri, Oct 09, 2020 at 10:39:26AM +0100, Julien Grall wrote:
> > On 08/10/2020 19:39, Elliott Mitchell wrote:
> > > Your (Masami Hiramatsu) patch seems plausible, but things haven't
> > > progressed enough for me to endorse it.  Looks like something closer to
> > > the core of ACPI still needs further work, Julien Grall?
> > I didn't go very far during my testing because QEMU is providing ACPI
> > 5.1 (Xen only supports 6.0+ so far).
> >
> > For your log above, Xen finished to boot and now dom0 should start
> > booting. The lack of console output may be because of a crash in Linux
> > during earlyboot.
> >
> > Do you have the early console enabled Linux? This can be done by adding
> > earlycon=xenboot on the Linux command line.
> Finding all the command-line console settings can be a challenge.  I had
> thought it was supposed to be "console=hvc0 earlycon=hvc0".
>
> With that though I finally have some output which claims to come from the
> Linux kernel (yay! finally hit this point!).  As we were both guessing,
> very early kernel panic:
>
> [    0.000000] efi: Getting EFI parameters from FDT:
> [    0.000000] efi: Can't find 'System Table' in device tree!
Thank you for sending part of the log. Looking at Linux 5.6 code, the 
error message is printed by efi_get_fdt_params() (see 
drivers/firmware/efi.c) when one of the property is missing.
'System Table' suggests that Linux wasn't enable to find 
"linux,uefi-system-table" or "xen,uefi-system-table".
Xen will only create later. Would it be possible to add some code in 
__find_uefi_params() to confirm which property Linux thinks is missing?
> [    0.000000] cma: Failed to reserve 64 MiB
> [    0.000000] Kernel panic - not syncing: Failed to allocate page table page
>
> I don't know whether this is a problem with the mini-DT which was passed
> in versus ACPI tables.  I note a complete lack of ACPI table information.
I think this is normal because, IIRC, the ACPI root pointer will be 
found using the System Table.
> The kernel is from a 5.6-based kernel tree.  I'm unsure which portion to
> try updating next.
Cheers,

--
Julien Grall