Re: [PATCH] virtio: Remove virtio devices on device_shutdown()

[Kirill A. Shutemov]

On Thu, Aug 08, 2024 at 01:37:42PM +0200, Jiri Pirko wrote:
> Thu, Aug 08, 2024 at 09:51:41AM CEST, kirill.shutemov@xxxxxxxxxxxxxxx wrote:
> >Hongyu reported a hang on kexec in a VM. QEMU reported invalid memory
> >accesses during the hang.
> >
> >	Invalid read at addr 0x102877002, size 2, region '(null)', reason: rejected
> >	Invalid write at addr 0x102877A44, size 2, region '(null)', reason: rejected
> >	...
> >
> >It was traced down to virtio-console. Kexec works fine if virtio-console
> >is not in use.
> >
> >Looks like virtio-console continues to write to the MMIO even after
> >underlying virtio-pci device is removed.
> >
> >The problem can be mitigated by removing all virtio devices on virtio
> >bus shutdown.
> >
> >Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> >Reported-by: Hongyu Ning <hongyu.ning@xxxxxxxxxxxxxxx>
> 
> Could you provide a "Fixes:" tag pointing to the commit that introduced
> the bug?

I am not sure if it is a regression. Maybe it was there forever.

Hongyu, could you please check with bisect if it is possible to point to a
specific commit?

-- 
  Kiryl Shutsemau / Kirill A. Shutemov