On Tue, Sep 29, 2020 at 04:05:21PM +0200, Jürgen Groß wrote:

On 29.09.20 14:41, Marek Marczykowski-Górecki wrote:

quoted

On Tue, Sep 29, 2020 at 03:27:43PM +0300, Denis Efremov wrote:

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Hi,

On 9/28/20 12:36 PM, Marek Marczykowski-Górecki wrote:

quoted

On Mon, Sep 28, 2020 at 07:02:19AM +0200, Jürgen Groß wrote:

quoted

On 27.09.20 13:14, Marek Marczykowski-Górecki wrote:

quoted

Hi all,

I get kernel panic on 'floppy' module load. If I blacklist the module,
then everything works.
The issue happens in Xen HVM, other virtualization modes (PV, PVH) works
fine. PV dom0 works too. I haven't tried bare metal, but I assume it
works fine too.

Could you please try bare metal?

I don't have any hw with floppy controller at hand...
Booting on what I have, it works, loading floppy just says -ENODEV.

I saw that the issue was bisected [1] to commit
c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a
per interrupt XEN data pointer which contains XEN specific information.")

I have hardware, but I've never worked with Xen. It will take me some time
to set it up and reproduce the problem. I think I will do it in a week.

Can you try to boot 4.19.143 (or any other including that commit)
directly on the hardware and make sure floppy module is loaded? We do
know it's broken in Xen HVM, it would be interested to see if it works
without Xen. Even better if you could use the same kernel config:
https://gist.github.com/marmarek/1e6a359c9a99af3ed8fc16af0f36d8a6

I think it is not directly related to floppy, but a more general problem
for HVM guests.

I'm suspecting an issue with legacy IRQs. Could you please try the
attached patch?

Yes, this fixes the issue.

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?