Re: Xen 4.14.0 is busted on Dell 300x IoT Gateways

From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Roman Shaposhnik <roman@zededa.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>,
	"Paul Durrant" <paul@xen.org>, "Jan Beulich" <jbeulich@suse.com>,
	"Juergen Gross" <jgross@suse.com>,
	"Boris Ostrovsky" <boris.ostrovsky@oracle.com>
Subject: Re: Xen 4.14.0 is busted on Dell 300x IoT Gateways
Date: Tue, 18 Aug 2020 23:20:35 +0100	[thread overview]
Message-ID: <0f6b9a9d-e25f-c2ae-ea2b-fd13107a3b06@citrix.com> (raw)
In-Reply-To: <CAMmSBy9-cJuxC0jLPh6O-UCraThzg2wvNO29ZvxrBmVkatt_sg@mail.gmail.com>

On 18/08/2020 23:09, Roman Shaposhnik wrote:
> Hi!
>
> first things first -- booting on those devices have always
> required efi=no-rs

That is a bug.  Please start a separate thread about it.  EFI Runtime
Services are de-facto mandatory on modern systems, and it is totally
unacceptable (from a users perspective) that Xen just doesn't work by
default.

It needs fixing.

> -- but it seems that Xen 4.14 is now 
> busted at a more fundamental level. I'm attaching two
> boot sequences (one with kernel 4.19.5 and one with 5.4.51)
> in the hopes that this may provide some clues right away.

As a note, from your logs:

Kernel command line: console=hvc0 root=(hd0,gpt1)/rootfs.img
dom0_mem=1024M,max:1024M dom0_max_vcpus=1 dom0_vcpus_pin
eve_mem=650M,max:650M eve_max_vcpus=1 ctrd_mem=300M,max:300M
ctrd_max_vcpus=1 rootdelay=3 setup_loops eve_installer

You've got some Xen command line parameters on the Kernel command line,
which won't be helping matters.

>
> Any help would be greatly appreciated!
>
> Oh, and finally it appears that this is NOT a regression from
> Xen 4.13 -- it fails the same way. I haven't tried Xen's earlier
> than that.

This is a Linux issue, not a Xen issue.

It is hitting a BUG_ON() while setting up interrupts.

Interestingly, they are both in byt_gpio_runtime_resume() which I guess
is BayTrail as the Intel platform, which probably means that something
pertaining to GPIO interrupts isn't being initialised normally.

~Andrew