Regular oops on shutdown of KVM/ARM64 machines with VGA device

On Tue, Jun 30, 2015 at 08:46:28AM +0100, Dirk M?ller wrote:

Hi Mark,

quoted

I've seen issues with prior FW versions where the ethernet controller
was erroneously left active after ExitBootServices(), and would DMA
braodcast packets over the kernel. That resulted in similar failures to
what you're reporting.

Can you reproduce the issue with all ethernet cables unplugged?

not with ethernet cables unplugged, but I did ifdown on all interfaces
and was able to trigger the issue just fine. Please note it is 100%
reproducible in one sequence each and every time, which imho makes it
unlikely to be a DMA scatter issue.

I see; agreed.

quoted

You can also try enabling CONFIG_MEMTEST (and pass memtest on the
command line) at boot time, which may happen to catch DMA in the act.

Did not try this.

Given the above it sounds like it wouldn't help anyway ;)

Sorry for the noise!

Mark.